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CHAPTER 7

USING THE DEMONSTRATION DISKETTE

7.1 Introduction

The demonstration diskette has been designed to provide an introduction to handling a database package. Even for those with very little or no experience of computers it should be possible to learn the basic operations after a few hours, and certainly within a few days.

This chapter is divided into the following main sections:

7.2 Hardware and operating system requirements

7.3 Installing and running the package

7.4 Basic operating procedures: using the HAEMANTH database

7.5 Creating a simple database

7.6 Building a database made up of several tables

7.7 Manipulating the database MED_ALL

If you want only a preliminary introduction to using a database then there may be no need to go beyond section 7.4. If, on the other hand, you want a more complete introduction then carry on through all the sections. Once the basic principles are understood there is nothing to stop you from experimenting further with the example data given, or from entering and handling your own data.

An important point to remember is to work at your own pace and to take plenty of breaks from the computer. It is probably better to keep working sessions fairly short (no more than about an hour) rather than attempting to work through large chunks of this chapter in long (and probably exhausting) sessions.

All the database operations and example files are contained in the diskette. However, as this is a demonstration package only a limited number of records (i.e. 150) can be entered into a new database. The package is designed to run on machines using either DOS or Windows 95/Windows 98. If your computer runs on one of the other Windows operating systems (such as Windows 3.11) then, as described below, it is a simple matter to exit into DOS from Windows.

7.2 Hardware and operating system requirements

The demonstration database package can be run on any IBM or IBM-compatible computer, from an 8086/8088 (or XT) to a Pentium; that is, either on any machine that uses (or can adapt to) the DOS operating system, or on a machine that uses Windows 95/Windows 98. If you are using Windows 95/Windows 98 it is essential to use a Microsoft mouse (or genuine equivalent), which ensures that the file "Mouse DRV" is loaded on the C:\Windows\System subdirectory. (If you have a problem with this specific aspect, your PC supplier should be able to assist).

There is no need to add extra RAM, although this could this could improve the efficiency of operation. It is essential, however, that the computer is fitted with a mouse. This is because most of the operations in the package use mouse-driven menus, as will be explained below. If need be, it is not expensive to buy a mouse (see Chapter 3). When a mouse is bought it comes with a diskette containing the software needed to drive it. This software must be loaded according to the instructions on the diskette, which will also update the AUTOEXEC.BAT (i.e. a batch file contained in the computer and used for storing a series of commands, such as those needed to drive a mouse each time the computer is switched on). This is a procedure that can be explained at a computer shop. Note that if you are operating in Windows 95/Windows 98, mouse software is automatically included and you can therefore ignore the above instructions.

A colour screen (VGA or super VGA) is also essential as a monochrome screen cannot show some of the highlighting provided in the package. In addition, the computer must have a hard disk storage capacity of at least 20Mb, only a small part of this (1-2 Mb) being required to load the package.

The computer will have either a 5¼" or a 3½" drive (or both in some machines). If the computer does not have a 3½" drive then it should be quite easy to have a 5¼" copy made from the 3½" diskette provided. It is strongly recommended that you make at least one backup copy of the diskette as a safety precaution.

7.3 Installing and running the package

The installation process is as follows:

(a) Non-Windows 95/98 operating systems

The first step is to switch the machine on, so that the DOS prompt appears (i.e. C:\>). This prompt will appear automatically in DOS machines. However, if your machine operates in Windows 3.11 then exit from the Windows screen into DOS. Now place the diskette into the appropriate drive (5¼" or 3½") that will be designated as A: or B: on the computer.

Make sure the diskette is locked into position and type in A: or B: (depending on the drive being used) and press Enter. The screen should then show the A:\> or B:\> characters (or prompt). At this point, type in INSTALL and press Enter. There will be a slight delay as the installation process takes place; that is, while the package is copied onto the hard disk -- or "C drive" as it usually known.

The prompt C:\PLANT_DB should come up on the screen. Now type in PLANT_DB and press Enter. When this is done a display will appear on the screen, as shown in Figure 7.1. This is the Main menu. The position of the mouse cursor is marked by a small rectangular block on the screen which will move as the mouse is shifted about. You can now begin to try out the various operating procedures and examples that are described below.

Figure 7.1 The Main menu as it appears on the computer screen: note that the parts of the menu within | | markers will appear in blue on the computer screen; these are the strips which must be clicked onto with the mouse in order to perform the operations indicated (each of these functions will be described below). Nothing will happen if the mouse is clicked outside the blue areas.

MAIN MENU

+--------------------------------------------------------------+

¦ ¦

¦ CLICK ONTO THE DESIRED OPERATION ¦

¦ ¦

¦ |New Database| Set up a new Database Framework ¦

¦ |Import Data| From an 'ASCII' file to Database ¦

¦ |Load Database| Make Database Ready for Processing ¦

¦ |Operate Database| View/Manipulate the Loaded Database ¦

¦ |Delete Database| Erase the Loaded Database ¦

¦ |Add Field| Add a Field to a Database ¦

¦ |Erase Field| Erase a Field from a Database ¦

¦ |Copy Database| Copy Loaded Database to Another ¦

¦ |Join Databases| Join Two Databases Together ¦

¦ |Add Databases| Add One Database to the End of Another ¦

¦ |EXIT| Return to DOS ¦

¦ ¦

+--------------------------------------------------------------+

¢ (1998) Michael Berjak and Jeremy Grimsdell

In order to switch off the computer, return to the Main menu, select EXIT and then switch the machine off.

The installation process will store the package in the computer (i.e. on the hard-drive) and need only be done once. Thereafter the package may be run as follows. First switch on the computer and, when the DOS prompt appears (or has been reached via Windows 3.11), type in CD\PLANT_DB and press Enter. This step should produce the C:\PLANT_DB> prompt. At this point type in PLANT_DB, press Enter, and the Main menu will appear. The package is now ready to use.

(Note that the _ symbol, known as Underscore, is obtained by pressing Shift and the minus key at the same time.)

Two important points need to be made here. The first is that if at any time you exit from the package and then wish to return to the package, type in PLANT_DB at the prompt (i.e. C:\PLANT_DB>) and the Main menu will appear again. It may happen that you exit from the package by mistake -- as can occur if a wrong key is pressed. There is no need to panic if this happens: simply return to the package as just explained.

The second point is that if in the rare event you get completely stuck (as might happen if, for instance, a letter instead of a number is entered in certain parts of the package) then it is necessary to switch the computer off and on again (i.e. re-boot the computer). You then need to bring the C:\PLANT_DB prompt back to the screen, type in PLANT_DB and return to

the Main menu. No harm can occur to the package when you do this.

(b) Windows 95/98 operating system

Install the package as with any other Windows 95/98 package (but note that the package must be installed on the C drive and not the D drive if more than one hard drive is present). That is, place the diskette into the 3½" drive and make the following selections on the screen:

Begin with Start;

then Run;

then Browse (on the Run menu);

then use the down arrow on the Look In screen;

then 3½ Floppy;

then select Winstall;

then select Open;

then OK.

The package will then be loaded onto the hard disk. Close the installation window (click onto X) and find the Plant_DB icon; double-click onto the icon and the Main menu of the package will appear. You can now use the package as described below; click onto EXIT on the Main menu in order to return to the Windows front screen.

Once the package is installed in this way, merely click onto the Plant_DB icon (on the Desktop or Windows front screen) whenever you want to use the package.

7.4 Basic operating procedures: using the HAEMANTH database

7.4.1 The example database

The basic operating procedures of the package can be demonstrated on an example database that is included in the diskette. This example database, called HAEMANTH, contains information on the distribution of Haemanthus species in Southern Africa. The design of the database is shown in Figure 7.2. The reason for having fields for each of the eight regions is that some species occur in more than one region and therefore, following the principle of atomising data, separate fields are needed for each region.

(Figure 7.2 about here)

The operating procedures can now be described, starting with loading the database HAEMANTH.

It should be noted that these operations can be summoned in order within certain logical limits; namely that a database cannot be operated until it has been loaded, and that it cannot be loaded until it has been constructed.

7.4.2 Load Database

Starting at the Main menu, find the operation called Load Database and move the rectangular cursor of the mouse anywhere onto the blue strip labelled |Load Database|. Once the mouse is clicked (using the left-hand button for all operations), a list of databases will appear in blue on the screen. This list, as shown below, is merely an example of what could be displayed at this point, and the order in which database names appear on the screen may differ from that in this listing.

For the purpose of this demonstration move the mouse cursor to the example database called HAEMANTH and click onto the blue strip. This will load the database to be worked on, in this case HAEMANTH. The computer will then return to the Main menu. You will note that the name of the database you are working on appears at the bottom right position on the screen.

Assuming that a database has been loaded, the majority of operations available on the Main menu can now be used. However, should you try to operate a database before one has been loaded the following remark will appear on the screen:

And, as indicated on the screen, in order to get back to the Main menu simply press any key on the keyboard.

7.4.3 Copy Database

Before proceeding to look at specific database operations, it is essential to copy the database (in this instance HAEMANTH) to a working copy which can be altered without affecting the original. Accordingly, click onto |Copy Database| on the Main menu. A further menu (or sub-menu) will now appear as follows:

Do You Wish to Continue (or Cancel) the Process of Copying a Database?

|Continue| or |Cancel|

If |Cancel| is selected the Main menu will return. However, when |Continue| is clicked you will be asked to:

ENTER THE NAME OF THE DATABASE TO BE COPIED TO (N.B. UP TO 8 CHARACTERS) EXCLUDE EXTENSION

This instruction means that you should use no more than eight letters or numerals as a name. You can also use the Underscore character if you like (e.g. GEN_SPEC), but you should not have any breaks in the letters; nor should you use punctuation or any symbols on the keyboard as characters because these are reserved for certain DOS conventions. In particular, you should not use a so-called Extension; that is, two expressions connected by a full stop (e.g. GEN.SPEC).

For this demonstration choose WORKING as a suitable name and type this in. Then press the Enter button and the Main menu will reappear. As the copied database is not loaded yet, click onto |Load Database|. The newly copied database named WORKING will now appear as a choice on the screen and should be selected. The Main menu will then return once more.

7.4.4 Operate Database

This operation will only work once a database has been loaded. However, as a database has been loaded (i.e. WORKING), click onto |Operate Database| and another sub-menu (the View sub-menu) will come onto the screen as follows:

View the Database in Table or Record Format

|Table| or |Record| or |Field| or |Exit|

(Note that |Field| is a special case of using the Record structure and will be ignored in this book).

7.4.5 Record Format: list of operations

For the purpose of this demonstration select the Record Format (i.e click onto |Record|). The first database record (for WORKING) will then be displayed, with field titles shown on a red background, followed by the appropriate data. The position of the record in the database (e.g. Record No. 1 of 26) and the database name (i.e. WORKING) are given at the bottom right-hand corner of the screen. At the foot of the screen is a further sub-menu on a blue background, as shown below:

|Next Record| |Previous Record|

|Enter New Record| |Delete Record|

|Sort Database| |Edit Record|

|Project Database| |Print Database|

|Export Database| |Exit|

|GoTo Record No.|

By clicking onto |Next Record| the next entry in the file will be shown, and by continuing in this manner all the records presently stored in this database can be viewed one at a time. To go backwards through the records of the database merely click onto |Previous Record|. If the Next Record option is chosen when the last record is on the screen (i.e. Record 26 of 26) a return is made to the View sub-menu. You may notice while going through the database in this manner that the position on screen of each record may vary slightly from others in the database. This is because the database programs have been designed to get the most out of the screen layout by fitting the data fields together as tightly as possible.

Having looked at the records in the database, the next step is to try out some alterations, as listed below. Remember that as you will be working on a copy no damage can be done to the original database HAEMANTH. Sometimes the mouse cursor may slip and when clicked, select an unwanted choice. For example, |Enter New Record| may be selected instead of |Next Record|, or |Delete Record| instead of |Previous Record|. However, such unwanted choices can be avoided as a further sub-menu will appear asking whether you wish to continue or reject the selection. By clicking onto |Cancel| the computer will return to the previous screen and the correct operation can then be selected.

(a) Enter New Record

This option appears near the top of the View sub-menu. For demonstration purposes, suppose a new species of Haemanthus has been discovered called "paucifolius" and that this record needs to be included in the database. Clicking onto |Enter New Record| will bring up the sub-menu:

Do You Wish to Continue (or Cancel) the Process of Creating a New Record?

|Continue| or |Cancel|

|Continue| will call up the first field, Family Name, on a red background for entry. This is followed by an instruction on how the entry should be written (i.e. can be alphabetic or numeric and include punctuation) and what the maximum length of the field entry can be (i.e. 30 characters). The instruction can change depending on the field; in this example, you will notice a change when the fields for Regions are reached.

For Family Name, type in Amaryllidaceae and then press Enter. This will bring up the next field to enter.

Complete the new record exactly as listed below (i.e. with due regard to upper and lower case letters), and press the Enter key after typing in each data entry (i.e. as enclosed by inverted commas). For those unfamiliar with computer keyboards, use the Backspace or Delete keys to remove any typing errors.

For Genus Name, type in Haemanthus

For Species Name, type in PAUCIFOLIUS

For Subspecies, just press Enter as there is no entry in this example

For Region T, type in T

As Region T is the only region where the new species is found, all other fields for regions must be left blank; so for these just press Enter.

When you have entered the last field (i.e. Region B) the following instruction will appear:

|Create Another Record| |Exit|

As there is no further record to enter, click onto Exit and the Record Format sub-menu will reappear on the screen. You will notice that there are now twenty-seven records in the database, the last being the one just created.

(b) GoTo Record No.

Now click onto this option and the following question will come up on the screen:

Enter the required record number.

Any number in the range 1 to 27 can be entered. If a number is entered outside of the present record set, it will be rejected. However, to view the newly created record, type in 27 and press Enter. The record you have just created will then appear.

Certain conventions are followed when entering records into the database. For example, Species Name is always written in lower case letters. The name of the species in the newly created record was entered in upper case, a deliberate mistake in this case. However this mistake can be easily corrected.

Click onto |Edit Record| with the record needing to be edited on the screen (i.e. record 27). The field titles will now be displayed on a green background, together with the instruction:

To SELECT:CLICK ON HIGHLIGHT

As the entry in the field Species Name needs alteration, click onto this field. The screen will then come up with a further instruction:

ENTER ALPHABETIC OR NUMERIC DATA OR PUNCTUATION (UP TO 30 CHARACTERS)

This specification on how the data should be written is the same as that given when the new record was entered. This topic will come up again later in this chapter when a new database is created. At this point, however, type in the correct lettering of the species name (i.e. paucifolius) and press Enter. The record will then reappear at once with the alteration in place. Other fields can be edited in the same way.

(d) Delete Record

The record presently on the screen will be deleted completely if this option is used. However, after selecting this option the deletion can be cancelled because the message:

Do You Wish to Continue (or Cancel) the Process of Deleting a Record

|Continue| or |Cancel|

provides for continuation or rejection of the operation. If |Continue| is selected, the record will be deleted and cannot be retrieved. There is no need to try out this operation as the explanation is sufficient.

(e) Sort Database

As only one field can be sorted at a time, sorting is sometimes a lengthy operation, and with large databases one has to be patient while this takes place.

The new record (for the entry paucifolius) has been entered at the end of the file. All the other records were arranged in alphabetical order according to species name (albiflos, amarylloides....unifoliatus), and by sorting on Species Name the new record can be put into its correct position in the file. It is important to note that the sorting takes into account whether the letters entered are upper or lower case. All upper case characters (A..Z) take precedence over lower case (a..z). Therefore make sure that the correct case is used (i.e. paucifolius, not Paucifolius) otherwise the end result will not turn out as expected.

The operation is as follows. Click onto |Sort Database| which results in the Continue/Cancel sub-menu. Click onto |Continue| and the highlighted field names will appear. It is on Species Name that the sort is to be performed so click onto this option. The message:

***** SORT IN PROGRESS *****

will stay on the screen until the process is finished. However, depending on the hardware being used, the sorting can be so rapid that this message does not appear. The Record Format sub-menu will reappear on the screen. By starting at record 1 and going right through the file using |Next Record| the revised order can be seen. The record with species name paucifolius is now number 20.

Any of the other fields in the database can be sorted in a similar manner.

(f) Project Database

On many occasions a selected file of data has more fields than are useful for a particular need (see previous chapter). Although inadvisable to get rid of seemingly unnecessary records on a permanent basis, it is very useful to be able to make a temporary copy of the database containing just the fields that are required. The original database (WORKING in this case) will be unaltered by this operation and, every time performed, a new database called TEMP (short for Temporary) will be created.

In order to try out this option, first click onto |Project Database|. The following sub-menu will then appear:

Do You Wish to Continue (or Cancel) the Process of Projecting the Database?

|Continue| or |Cancel|

When |Continue| is chosen the names of the first ten fields (the others will come up later) will be presented on the screen with the message:

INCLUDE FIELD 1

|Yes| or |No|

Please note, by the way, that if an incorrect choice is made there is no means of going back. But if this does happen, complete the operation, by answering |Yes| or |No| to all the questions, and when the Record Format comes back, select |Project Database| again. Then repeat the operations.

|Yes| will include the field in the resultant database; |No| will leave it out. As an example, using the database WORKING, retain all fields up to number 8 (Region C) and omit the remainder by clicking Yes for fields 1 to 8 and No for the remainder. As the click is made for field 10 the next range of field numbers (11 to 12) will appear on the screen. Just continue in the same manner until all fields have been dealt with. At this point, the message

PROCESSING PLEASE WAIT

will flash in red on the screen. In this example, with only 27 records, the processing will be rapid -- so rapid on some computers that the message will not be seen. But it will take much longer for large files of records and so patience may be needed. Once completed, the screen will return to the Record Format sub-menu; that is, for the original database (WORKING).

In order to see the new database, Exit from the Record Format sub-menu and also from the next sub-menu to get back to the Main menu. Now click onto |Load Database| and find the title TEMP in the list of databases. Select this database and then click onto |Operate Database| followed by |Record| to view what has been produced. In this case, this will be a database containing just the eight fields that were selected.

As mentioned above, a database called TEMP will be created every time the Project Database operation is carried out. However, each new TEMP will replace the old one, and so if you wish to keep a TEMP database it should first be loaded, then copied and renamed using the |Copy Database| operation on the Main menu. This process needs to be carried out with discretion, as there is a risk that a large number of databases will be created, so making the system more difficult to operate.

When copying a file, make sure that the name you give is not the same as that of another database, otherwise the latter will be overwritten and lost.

(g) Print Database

This option is to be found on the Record Format sub-menu. If you select this option then the following instruction will come up on the screen:

PLEASE ENSURE THAT THE PRINTER IS ON-LINE AND SWITCHED ON N.B. IF A PRINTER IS NOT CONNECTED OR NOT SWITCHED ON, YOU WILL HAVE TO RE-BOOT YOUR MACHINE. IF YOU ANSWER YES DO YOU WISH TO CONTINUE PRINTING?

Provided the printer is correctly connected, printing will start immediately |Yes| is selected. All the records in the database (in this case WORKING) will be printed one by one in the same form as the records were presented on the screen. When the printing has finished, click onto |CONTINUE| which will bring back the View sub-menu. A return to Record Format can then be made.

However, if |Yes| is selected when the printer is not connected properly (or perhaps not connected at all) then it will be necessary to "re-boot" the computer (i.e. switch it off and on again). (However, Windows 95/98 will merely return to the RECORD screen with a mention of the non-connection of a printer). This will not damage the package in any way; all that will happen is that the DOS prompt will reappear (or, for example, the Windows 95 screen). You will then have to load the package again in order to get back to the Main menu.

If a particular form of printed output is needed, then use the Export facility (see below) to transfer the data to another package, such as a word processor or spreadsheet package.

(h) Export Database

This operation is similar in some ways to printing, except that the output goes to an ASCII file (see Chapter 1) rather than to a printer. Click onto |Export Database| and a sub-menu is brought up as follows:

Do You Wish to Produce a Fixed Length or a Delimited Output File?

This means that you can choose between two forms of ASCII files -- either Fixed Length or Delimited. Both of these outputs are suitable for many packages (for example, for database packages such as dBase, Oracle, Paradox or Foxpro). In general, the delimited form is preferable as it is more compact and convenient to handle.

By clicking onto |Fixed Length| the output will be immediately placed into a file called PRINT_DB.ASC (i.e. Print Database in ASCII form). In this form, each field occupies a fixed length depending on its definition. For instance, an alphabetic field of 30 spaces containing the name Haemanthus would be presented in the file as:

Haemanthus???????????????????? , where ? depicts a blank.

On the other hand, the |Delimited| option will request you to:

ENTER THE (SINGLE) DELIMITER CHARACTER e.g. | or ,

This means that you have to choose a suitable single character to delimit the fields in the database. You can choose between an upright slash (|) or a comma as a delimiting character. Once a suitable character is entered the screen will display the following message:

THE OUTPUT FILE WILL BE LODGED IN FILE "PRINT_DB.ASC" ON THIS DRIVE & DIRECTORY

PROCESSING : PLEASE BE PATIENT (blinking in red)

This line will then change to:

PROCESSING NOW COMPLETED (blinking in red)

The file "PRINT_DB.ASC" is now in a form suitable for export -- for instance via a diskette. Note that if another ASCII file is made it will overwrite the previous one, so it is necessary to save (e.g. on diskette) important files.

The |CONTINUE| strip will also appear in blue at the foot of the screen. Once the mouse is clicked onto this strip the Record Format sub-menu (for WORKING) will return. Exit from this and the View sub-menu will come up again.

7.4.6 Table Format: list of operations

Now select the |Table| option on the View sub-menu. Immediately a table will appear on the screen with column headings corresponding with the field names of the database (WORKING) and the rows consisting of the first twenty records of the database (labelled 1 to 20 on the right-hand side). At the foot of the screen will be the Table Format sub-menu (in blue), as shown below:

Each of these operations will be described in turn. Note that the mouse cursor will be somewhere on the screen; if you are unsure where it is then move the mouse and watch the cursor move.

(a) Page Down

This will bring up the next page of the table. However, there will have to be more than twenty records in the database for another page to appear. By clicking onto |Page Down|, records 21 to 27 of the database WORKING will now be displayed. If you click onto |Page Down| again, the following message will appear at the bottom right-hand corner of the screen:

AT END OF FILE SELECT AGAIN

At this point one of the other options should be selected.

(b) Page Up

Clicking onto this option will bring back the first page of the table (records 1 to 20), but if selected at the start of a file (i.e. top of table) will bring up the message:

AT START OF FILE SELECT AGAIN

Each click of the mouse on this option will move the table one field to the right until the last field is displayed. At this point the following message will appear:

AT END OF DATA SELECT AGAIN

Note that at any time while doing this the Page Up or Page Down options may be selected to obtain vertical movement.

(d) Left Fields

This operation allows movement of the table one field to the left, otherwise it is the same as the above command.

(e) Cursor Operation (editing)

This option is used for editing purposes and is somewhat more involved than editing in Record Format. Once the |Cursor Operation| selection is made, a new sub-menu will appear at the foot of the table, as follows:

|Edit| (Highlighted Field) |Esc| To Exit

You will also notice that the top data entry of the left hand column is highlighted in white. This highlighted block can be moved around the table on the screen by clicking onto |Right|,|Left|,|Down| or |Up| at the bottom of the table (in blue). The white block is used to mark a field that needs editing.

In order to mark an item in any part of the table not in view, click onto |Esc| - i.e.Escape -

and the previous sub-menu will return. This will allow you to find the relevant part of the table; then the |Cursor Operation| option can be clicked onto again.

To take an example, suppose that the species Haemanthus avosmontanus (record 5) has been found in Region C, a region where it was not recorded before. A new entry therefore has to be made. However, before selecting |Cursor Operation|, use |Right Fields| repeatedly until the column headed Region C is on the screen. Now click onto |Cursor Operations| and note the white block that appears in the top-left position. Using |Right| and |Down|, move the block to the column Region C opposite record number 5, which will be empty. Now click onto |Edit|, type in a C and then press Enter. As soon as Enter is pressed the new entry will fall into the correct position.

In this way, you can make as many alterations as needed on the part of the table in view. The white block will remain at the position of the change until |Esc| is selected. If an incorrect entry is made, then merely re-edit until the correct result is obtained.

It should be noted that any editing carried out in Table Format will be reflected in Record Format, and the other way around.

(f) Select (first example)

This option (on the Table Format sub-menu) is used to make selections of records that meet certain criteria, as explained in the previous chapter. Such selections can be simple or complex. A simple selection may involve only one field and an example of this type of selection will be given first. Note that there is no need to have the field (i.e. column) on which operations are to be made in view; all selection operations are carried out by the computer, irrespective of whether the fields are on the screen or not.

Using the database WORKING, suppose one needs to know which species of Haemanthus are found in Region N. By looking at the screen when Region N is one of the columns in view it is obvious that only four species are found in this region. This is clearly a very easy selection for which a computer would not be needed, but is given here purely as a demonstration of the procedure involved. It can be noted, however, that a computer selection of this kind would be useful, if not essential, for large databases of plant species (for example, there are more than 20 000 species included in the database of South African plants, PRECIS).

The command clause for the operation is as follows:

SELECT <WORKING> WHERE Region N = N

To begin the selection process, click onto |Select| and a new table will appear containing the field headings (as listed in the first column of the table). A sub-menu will also appear at the foot of the table, as follows:

|Select| (Highlighted Field) |Esc| To Exit

A white block (or cursor) will be present at top-left of the table. For this selection the field Region N is needed so use the |Down| selection repeatedly until the block lands on Region N. Once there, click onto |Select|. A message will then appear as follows:

THE CHOICE MUST NOW BE MADE AS TO WHICH ATTRIBUTES IN THE FIELD SPECIFIED ARE TO BE SELECTED

THE ATTRIBUTE NUMBERS AND NAME ARE GIVEN SELECT (Y)ES OR (N)O AGAINST EACH ENTRY IN THE TABLE

You will notice a blue |CONTINUE| strip at the base of the screen. Click onto this strip and a new screen will appear with a column of attribute choices -- only one of which has the letter N next to it.

A sub-menu at the bottom of the screen is displayed as follows:

IS ATTRIBUTE 1 TO BE USED ?

| Yes | or | No | or |GoTo Next Page| or |End Search|

Now work through the list of attributes, choosing |Yes| when the attribute number corresponds to the letter N (representing Region N) and |No| when the attribute number corresponds to a blank (the blanks are of no importance and can be ignored).

When all the entries have been handled the sub-menu will disappear and the |CONTINUE| strip will be come onto the screen. Click onto this and the table of field headings will return. At this stage another column can be selected in combination with the one already handled (i.e. selection could be by two criteria, not one), but this option is not required in this case.

The next step is to click onto |Esc|. The computer will then make the selection for the criteria that have been given (i.e. which species occur in Region N). A code (or log) made up of letters and numbers may appear on the screen while the selection is being carried out. In most situations, this log can be ignored. When the selection is completed the Table Format will re-appear.

In Record Format, you will notice that the first of the four selected records appears in the usual way and when |Next Record| is chosen the remaining three records can be viewed in turn. This is because these four records, and no others in the database WORKING, had "N" against the Region N heading. You will also see that the arrangement of the individual records is the same as in the parent database WORKING. This will always be the case when selections are made; in other words, a faithful sub-set of the original table is created.

The database SELFIL can, once loaded, be copied and renamed. However, if the name entered is the same as that for another database, then the |Copy Database| operation will overwrite the previous database and all data (and headings) in it will be lost. It is also important to remember that if SELFIL (like TEMP) is not copied and renamed it will be replaced when another selection is made. The reason for creating SELFIL each time is to prevent huge numbers of unwanted databases from being created. Not only would this make the system more cumbersome to operate but the user would also be likely to lose track of what is stored where. Thus it is always up to the user to limit the number of databases and to delete unwanted ones as soon as possible; that is by using the option |Delete Database| on the Main menu. (There are ways to protect important databases from being inadvertently overwritten, but these methods will not be described here).

A further important point to note is that it is not possible to perform a further selection from SELFIL itself. This is because the resultant database will attempt to write over the database being used, an operation that cannot be done. If such a selection is required, then copy SELFIL to another name (e.g. ANOTHER) and then carry out the selection on this database.

(g) Select (second example)

This example will deal with a slightly more complex selection, as written below:

SELECT <WORKING> WHERE Region N = N AND Region S = S

SAVE SELFIL

PROJECT <SELFIL> OVER Species Name

SAVE REGS_NS

In other words, a command clause has been written to select just the records where species occur both in Region N and in Region S; then, secondly, to remove all fields except Species Name from the result. Incidentally, note that such a selection is possible because there is a separate field for each region; this selection would not be possible if there was just one field for all regions.

As the database you have just made will be in SELFIL, go back to the Main menu and load it. Then click onto |Operate Database| and choose Record Format. Now click onto |Project Database| followed by |Continue|. The first ten field names will appear on screen and, as only Species Name is wanted, answer |Yes| when INCLUDE FIELD 3 comes up and |No| to all the other options, including fields 11 to 12 when they appear. After this the message PROCESSING PLEASE WAIT may flash in red on the screen (you may not see this in faster machines), and when this is completed the View sub-menu will appear. Remember that the result of the Project Database operation is in TEMP, so go back to the Main menu and load it. Next click onto |Copy Database| followed by |Continue|. When asked to name the database type in REGS_NS (short for Regions N and S) and press Enter. Once the database has been copied, the Main menu will return. Finally, load REGS_NS which will now appear on the database list and view it in Record Format. You will see that just the field Species Name will be present and that only two records are contained in REGS_NS, the final result of this selection example.

When you have reached this point, you will have been through most of the basic operations of the package and can move on to the next section -- creating a simple database.

7.5 Creating a simple database

7.5.1 The example

The example database described in the last chapter can be used to demonstrate how to set up a simple database. This database, CONSERV, has eight fields, as shown in Figure 7.3

(Figure 7.3 about here)

7.5.2 Setting up the framework

Setting up the framework of a new database involves several steps: first naming the database, and then naming and defining the fields. In order to begin the process, click onto |New Database| on the Main menu. When this is done and confirmed, an instruction to name the new database comes onto the screen, as shown below. Click on to |CONTINUE| and the following instruction will appear.

ENTER THE FILE NAME FOR THE RESULTANT FILES

THIS WILL BE THE NAME FOR THE NEW DATABASE BEING CREATED N.B. USE UP TO 8 CHARACTERS FOR THE FILE NAME :EXCLUDE EXTENSION

e.g. DURBAN OR NEWCASTL (NOT NEWCASTLE - TOO LONG)

The name of this example database is CONSERV. Therefore type in this name and press Enter. Immediately, a new sub-menu will appear for Field 1 of the new database. In this example all the fields will be "Normal Fields"; therefore click onto |Normal Field|. You are then asked to give the title of the field, which in this case is "Genus". So type this in and press Enter. Another sub-menu will then appear in blue, as follow:

Indeterminate String of Letters/Numerals

String of Length 30

Number with Decimals

Larger Whole Numbers >32767

String of Length 7

String of Length 5

Single Letters or One Digit Numbers

Whole Numbers (-32767 to 32767)

This sub-menu allows you to define the field according to its content. A choice of |String of Length 30| would be appropriate here as genus names would be unlikely to have more than thirty letters. Once this option has been clicked onto, you are asked the following question:

Is there another field needing entering?

| Yes | or | No |

As there are more fields to be entered click onto |Yes| and repeat the procedure for fields 2 to 8, using the following specifications for these fields:

For the fields Species, Local Name and Part: choose |String of Length 30|

For the fields Life Form, Distribution and Threat: choose |String of Length 5|

For the field Bags: choose |Whole Numbers (-32767 to 32767)|

When the data specification for the last field (Field 8) has been entered, click onto |No| and the Main menu will return. You have now created the framework of the database; the next stage is to enter some data.

7.5.3 Entering data into the database

In order to enter data, first load the new database (listed as CONSERV) and operate the database in Record Format. The normal screen and sub-menu for Record Format will appear, but, as there are no records entered, the following comment is displayed at the top:

THERE ARE NO RECORDS IN THE DATABASE

However, by clicking onto |Enter New Record| followed by |Continue|, the process of entering data can begin. The first record can be completed using the following data items for each field (as taken from Figure 6.3):

Genus: Ocotea

Species: bullata

Local Name: Nukani,-u

Life Form: P2

Distribution: ul

Part: bark

Bags: 58

Threat: Vulnerable & Declining

Accordingly, type in Ocotea under Genus and press Enter. Then continue in a similar manner for the other fields. When the data item for the last field has been entered you can either create another record or exit; click onto |Exit| in this instance and the record you have just entered (i.e. Record No. 1) will be displayed immediately in the usual Record Format. You can then check that all entries have been made correctly; if not, use |Edit Record| to make any alterations.

Once the framework of a new database has been set up in this way, you may enter as many records as needed (although only up to 150 records can be entered in this demonstration package).

7.5.4 Adding or erasing fields

If required, it is possible to add an extra field (or fields) or to erase a field (or fields). To add a field, first load the database for which an extra field is needed, and then choose the option |Add Field| from the Main menu. Continue the operation and a select |No| from the new sub-menu that appears (i.e. choose Record Mode on the sub-menu). Then choose |Normal Field| from the next sub-menu, enter the name of the new field and specify the type of field required. You will then be asked if another field should be added. If |No| is selected the screen will return to the Main menu and you can then view the altered database in, say, Record Format. Use a similar procedure to erase a field (or fields): that is, load the relevant database, choose |Erase Field|, continue until the list of existing fields is displayed and then select the field to be erased.

7.5.5 Deleting a database

Should you wish to delete a database, simply select that option on the Main menu and the database currently loaded will be erased. This operation can be used, for example, to remove any unwanted databases when passing the package to another person to use; that person can then start with the original databases still in place and all others deleted.

7.6 Building a database made up of several tables

7.6.1 Conceptual model of the database

Having built a simple database, the next stage is to look at a more complicated example involving more than one table. A conceptual model of this example database is shown in Figure 7.4. It is essentially the same (although the field Bags has been omitted) as the simple database you have just made except that it includes associated tables. It is therefore an example of a relational database, consisting of a main table called MED_CONS (short for Medicinal Plants Conservation) and five associated tables linked to all the fields except Local Name. In this example the associated tables act as lists to assist with data entry and to ensure consistency; once formed, they will probably remain unaltered. However, there is nothing to stop you from adding extra records or fields (see above) to these associated tables if required.

(Figure 7.4 about here)

In order to demonstrate how tables may be constructed, the five associated tables are formed in three different ways in this example. The tables and their different origins are listed below:

(a) Tables GEN_SPEC and LF_LIST already exist as preformed databases in the package and can be loaded directly into the main table (MED_CON). You can look at these databases by loading then in the usual way.

(b) The table DIS_LIST exists as a separate ASCII file in the package and has to be imported into a table once the framework has been set up.

Also note that one field (Local Name) does not have an associated table; in this case the names have to be typed in at the keyboard when new records are entered into the database (as will become clear later).

The first stage in setting up this example database is to create the three tables that do not exist yet, namely tables THR_LIST, PAR_LIST and DIS_LIST.

7.6.2 Creating the tables THR_LIST, PAR_LIST and DIS_LIST

(a) THR_LIST (short for Threat List)

The table that has to be created is shown in Table 7.1. It consists of six records, made up of two fields -- Threat Category and Explanation.

(Table 7.1 about here)

Information now has to be entered into this new table (or database). Proceed, therefore, in the manner explained in section 7.5.3 and enter the six records contained in Table 7.1. Finally, inspect the records you have just created to verify that the information has been correctly entered. Remember that extra records or new information can be added at any stage.

(b) PAR_LIST (short for Part List)

The second associated table is a very simple one, storing only the names of the plant parts used. Again, use the |New Database| option on the Main menu, enter the name PAR_LIST and click onto |Normal Field|. There is only one field in this database, called Part. This field should be specified as |String of Length 30| as the names of the plant parts are short and simple, as shown below:

bark, roots, bulb, whole plant, leaves, stem, fruit, sap

Once set up, load the database and enter the eight records of the database, as given above.

This table will be created by importing an ASCII file in order to give an example of how this is done.

The ASCII file is contained in the Demonstration Diskette, and is composed of five records of three fields. You can view this information by exiting from the Main menu and typing in the words type distr.dat at the DOS prompt (i.e. C:\PLANT_DB>). The following output will then appear on the screen:

r|rare species||

uw|widespread|uncommon|

ul|occurring locally|uncommon|

cw|widespread|common|

cl|locally common|common|

This output shows the five records: each consists of three fields and these are separated by the upright slash symbol (|). Note that the third field in the first record is a blank and is recorded as ||. Having viewed this ASCII file, return to the Main menu by typing in PLANT_DB at the DOS prompt.

The next step is to create a framework to put the ASCII file into. Continue, therefore, in a similar manner as with the previous associated databases. Click onto |New Database| and type in the name DIS_LIST. Then prepare the database as follows:

Select |Normal Field|, name the first field Distribution and choose |String of Length 5|

Select |Normal Field|, name the second field Occurrence and choose |String of Length 30|

Select |Normal Field|, name the third field Abundance and choose |String of Length 30|

Once these three fields have been specified, select |No|, as there are no further fields to be included. The computer will then return to the Main menu. Now load the database you have just created (i.e. DIS_LIST). At this point a new operation should be selected, namely |Import Data|, that appears on the Main menu. When this option is chosen, an instruction comes onto the screen as follows:

ENTER NAME AND EXTENSION (IF ANY) OF THE TEXT FILE TO BE IMPORTED

The ASCII file can now be incorporated. Therefore at the prompt type in DISTR.DAT (in upper or lower case, it does not matter). Note that this file name does have an extension; that is, the letters DAT that follow immediately after the full stop. Once you have entered the file name, the next instruction will ask for the delimiter character. Type in an upright slash symbol (|) and press Enter. The computer may take a short time to import the data; it will then return to the Main menu. As the database has already been loaded, the next thing to do is to click onto |Operate Database|; it can now be viewed in either Record or Table Format.

7.6.3 Setting up the main table

Now that all associated tables are available, the main table, MED_CON, can be built. The initial stages are the same as setting up any new database. Therefore, select |New Database| from the Main menu and enter the name MED_CON. What is different from now on is the use of the Reserved/Normal Field sub-menu. This sub-menu is shown below.

-------------------------------------------------------------

Click onto one of the highlighted strips

|Reserved| i.e. are data to be loaded from an external Database

|Access| i.e. is this field to be used as an access mechanism to another Database

|Normal Field| i.e. standard Database field

_____________________________________________________________

(Note that the option |Access| will not be used in these examples)

The |Reserved| option does two things. First, it allows the specifications (i.e. string length, etc.) of any field that is selected from an external database to be transferred to the new database, and second, it forms a link between the two databases via this common field.

As associated tables (or external databases) are available that contain nearly all the fields needed for the database MED_CON, the |Reserved| option can be used to specify most of the fields in the database. Thus the first field required for the MED_CON database is Genus and this can be obtained from another database (i.e. GEN_SPEC). Therefore, click onto |Reserved| and a new sub-menu will then appear with the following instruction:

Now select The Database Which This Field Must Link To

Click onto |Continue| below this instruction and a list of all the databases currently loaded will appear. Select |GEN_SPEC| from the list. The two fields of this database will be displayed in blue, as shown below:

|Genus| |Species|

A link is required to the first of these fields so click onto |Genus|. Once this is done another sub-menu will come up asking whether there is another field that needs entering, and, as more fields are needed, click onto |Yes|. The Reserved/Normal Field sub-menu will then return.

For the second field, Species, exactly the same sequence of operations is carried out except that |Species| is selected. As before, choose |Yes| at the end of the sequence and return to the Reserved/Normal Field sub-menu.

The third field of the database is Local Name. This is the only field that does not have an associated database, and therefore the specifications of this field have to be entered. Accordingly, click onto |Normal Field|, enter the title Local Name, select |String of Length 30| and return to

the Reserved/Normal Field sub-menu.

All the remaining fields (i.e. Threat, Life Form, Part and Distribution) can be obtained from the associated databases. Therefore, use the |Reserved| option and select the following fields from these databases:

|Threat| from the database THR_LIST

|Life Form| from the database LF_LIST

|Part| from the database PAR_LIST

|Distribution| from the database DIS_LIST

Finally, respond |No| when asked whether another field needs to be entered and go through the usual procedure to view the new database (i.e. MED_CON). The stage is now set for entering data into the database.

7.6.4 Entering data into the database MED_CON

Only a few records need to be entered into the database in order to understand the procedures. After that you can use a preformed database called MED_ALL (short for Medicinal Plants: All Records) to try out various database manipulations. This database contains all the records (i.e. 130) required for the database MED_CON. You can either view MED_ALL on the computer screen, or as displayed in Table 7.2.

[Table 7.2 here]

Referring to Table 7.2, begin the process of entering a few records into the database MED_CON. When this database is viewed in Record Format the screen will come up with the message THERE ARE NO RECORDS IN THE DATABASE. This is to be expected as nothing has been fed into the database yet. To start the process, therefore, click onto |Enter New Record|, followed by |Continue|.

The first data item to enter is for the field Genus. This data item can be obtained from the list stored in the database GEN_SPEC. However, as this list is too long for all of it to fit onto the screen, you are presented with the following instruction:

FOR |Genus|

THERE ARE TOO MANY ENTRIES * ONLY 100 PERMITTED *

ENTER THE FIRST FEW LETTERS (UP TO FIVE) OF THE TARGET TO REDUCE THE SET

N.B. ONLY ONE FOR STRICTLY CHARACTER DATA (NOT STRINGS)

(Note that the last line of this instruction means that if the data items consist of a single letter -- e.g. C for Cape -- then only one letter should be entered).

Start with the first record listed in Table 7.2 as an example. The genus name for this record is Erythrophleum; the first letter (or the first few letters) of this word should be entered to allow the computer to list all the genus names that start with that (or those) letter(s). To see the possibilities type in just one letter: that is, an E. A selected list of names will then appear on the screen as follows:

CLICK ON HIGHLIGHT (BLUE)

NOW CHOOSE FOR FIELD |Genus|

When duplicate or multiple occurrences of a name are listed it means that there is more than one species of this genus present, but in the case of the genus Erythrophleum there is only one species, so click onto this single option. Another sub-menu will come up as follows:

Must all linked fields be updated or only the selected one?

| All | or | Selected Only |

As, in this instance, there are two fields in the MED_CON database which are linked to the GEN_SPEC database, the opportunity is being offered of obtaining all the necessary fields by one selection. It is clearly an advantage to accept this option so that both genus name and species name can be collected in one operation. Accordingly, choose |All|. The first (and in this case the only) entry for the genus Erythrophleum together with species name of lasianthum will then appear on the screen, as shown below:

|Genus| Erythrophleum |Species| lasianthum

Is this the master record to be loaded?

| Yes | or | No |

Click onto |Yes| and both these data items will be loaded into their correct fields.

The next field to be entered, Local Name, will then appear with the following instruction:

|Local Name| ENTER ALPHABETIC OR NUMERIC DATA OR PUNCTUATION (UP TO 30 CHARACTERS)

As this is a Normal Field (i.e. the data do not come from another database), the information has to be typed in. For this record the word Khwangu,-um should be entered.

The next field to enter is Threat. A sub-menu will now appear showing the options to choose, as shown below:

CLICK ON HIGHLIGHT (BLUE)

NOW CHOOSE FOR FIELD |Threat|

The correct entry for this field is |Declining| (see Table 7.2), so click onto this option.

In a similar manner, the remaining three fields are loaded by means of sub-menus. Thus for the field Life Form select P2; for the field Part select bark; and for the field Distribution select uw.

When all the fields in the first record have been entered, the following sub-menu comes up :

|Create Another Record| |Exit|

This sub-menu allows you to return to the Record Format sub-menu via |Exit| -- for example in order to edit a record -- or to carry on making records. If editing is done, use the |Enter New Record| option to continue with the record building process.

If you wish, you can enter a few more records in order to become familiar with the process. Note that the fifth record is slightly different because there are two entries in the GEN_SPEC database for the genus Eulophia and the correct one has to be selected. Click onto the first entry of |Eulophia| followed by |All| linked fields. The name of the species will then appear on the screen:

|Genus| Eulophia |Species| cucullata

This happens to be the correct species, so answer |Yes| to the question on the screen. In cases when the incorrect species comes up answer |No| and continue the search until the right entry is found. For example, the sixth record in Table 7.2 gives the genus Cassine which has two listed species: transvaalensis and papillosa. The second name is the one needed; therefore |Yes| should be answered only to the latter option in this case.

Once you have entered a few records, you will probably find the process rapid and convenient. And as nearly all the entries are chosen from menus, data entry is consistent. The advantage of setting up the database in this manner can now be appreciated. Admittedly, setting up the associated databases and the main database may appear quite complicated, but the advantages in data entry will often outweigh these initial complications.

7.7 Manipulating the database MED_ALL

7.7.1 The example database

As mentioned above, the database MED_ALL is available in the package. This database can used to demonstrate further examples of database manipulation. The first step is therefore to load MED_ALL and then follow the examples given below.

7.7.2 Selecting and sorting

To begin with, suppose there is a need to find all the species classified as Vulnerable & Declining and for which the part used is bark. The procedure is similar to that already given above (section 7.4). First view the database in Table Format. Then |Select| Threat using the cursor movements and |Select| again.

A new sub-menu will then appear that only comes up when the file contains over 100 records; this provides an opportunity to narrow down the search if there are many options to choose from. However, in this example there is no need to enter the first few letters of the data item to be selected as we know that there are only six entries to choose from. So click onto |No|. This will bring up the full list of six categories and category 6 (Vulnerable & Declining) is the one to select.

Remember that the database SELFIL holds the result of the selection (6 records in this example). In this example it may be useful to view the result in alphabetical order of genus. Accordingly, choose the Record Format of SELFIL; then |Sort Database| according to Genus and view the result in Table Format.

7.7.3 Joining databases

This operation has not yet been used, and will be demonstrated in this example. Suppose that the full description of the field Life Form is required for the selection (in SELFIL) made above. At present this field is denoted simply by a symbol, the meaning of which is given in the associated database LF_LIST. By using the operation |Join Databases| on the Main menu this extra information can be added.

What this operation does is to take the two databases in order to search for a matching field. If one is found, then a combined result is compiled. In this case a match is possible via the field Life Form, and therefore all the corresponding information in the database LF_LIST can be incorporated.

The first step is to make a copy of the database SELFIL to (say) VUL_DECL. The operation |Join Databases| should now be selected from the Main menu. Click onto |Continue| and a sub-menu will come up with an instruction:

Now Select The First File for the Join/Add

When |CONTINUE| is selected a list of all the databases loaded comes onto the screen, and VUL_DECL should be selected. A further sub-menu then appears asking for the second file needed for the join. Click onto |CONTINUE| and choose LF_LIST from the list.

The next sub-menu to appear highlights the fields of the first database (VUL_DECL) including the comment:

CLICK FOR FIRST DATABASE JOIN

(This instruction is asking for the field in question on which to join)

Therefore select |Life Form| as this is the field to be joined. Note that it is possible to make a join on several fields, but in this example there is only one. A sub-menu now comes up highlighting the fields of the second database, with the instruction:

CLICK ON CORRESPONDING JOIN

Clearly the option to select is |Life Form|. The next sub-menu to appear asks if there is another field to be included in the join, to which the response, in this example, is |No|.

At this stage another sub-menu will be displayed showing all the fields in the first database (VUL_DECL) with the following instruction:

SELECT OTHER FIELDS FROM DB1

The second database (DB2 -- or LF_LIST in this example) is now treated in a similar manner. Hence, click (one by one) onto the fields |Botanical Term| and |Description| prior to |Esc|.

The join will then be made by the computer and the screen will return to the Main menu. The result of the join operation will be found in a new database called JOINED. When this database is viewed in Record Format, you will see that the two fields describing the life form symbols are now included, as shown below:

P3 Bersama tysoniana Diyaza,-un Vulnerable & Declining bark uw PHANEPOPHYTES (R) microphanerophytes 2-5 m

P2 Curtisia dentata Lahleni,-um Vulnerable & Declining bark uw PHANEROPHYTES (P) mesophanerophytes 5-50 m

P2 Faurea macnaughtonii Sefo,-isi Vulnerable & Declining bark uw PHANEROPHYTES (P) mesophanerophytes 5-50 m

P2 Ocotea bullata Nukani,-u Vulnerable & Declining bark uw PHANEROPHYTES (P) mesophanerophytes 5-50 m

P2 Pleurostylia capensis Thunyelelwa,-u Vulnerable & Declining bark ul PHANEROPHYTES (P) mesophanerophytes 5-50 m

P2 Pleurostylia capensis Thunyelelwa,-u Vulnerable & Declining bark r PHANEROPHYTES (P) mesophanerophytes 5-50 m

As with TEMP and SELFIL, JOIN is a temporary database and must be copied if you wish to keep it.

7.7.4 Joining a further database

A further database can be joined to the result obtained above. This operation will not be explained in detail as it is similar to the one above. It is left to you to copy the result of the previous example (to say VD_ALL) and then join it with the database DIS_LIST on the field Distribution. This will add two fields explaining the distribution category. The final product, once again called JOINED, will have eleven fields, if all additional fields are included and all the operations are carried out successfully.

7.7.5 Removing unwanted fields

In this example the fields Distribution and Life Form can be removed from the database JOINED that you have made above. These fields could be considered unnecessary as their explanations are now included in the database.

To begin with, make a copy of the database JOINED and call it FINAL_VD. Then load this new database and operate in Record Format. Now click onto |Project Database| and follow the procedure described in section 7.4.

Use |Project Database| to exclude the fields Distribution and Life Form from the database. It should be noted that as there are eleven fields in FINAL_VD, the eleventh field (Abundance) does not appear on the first screen (as only ten are displayed at a time), but is carried over to the second screen. As soon as this last field is selected the computer will remove the unwanted fields and store the result in the database TEMP. This database will contain five records of nine fields each.

7.7.6 Selecting records according to specific criteria within a field

In this example a selection is made not only according to a particular field in a database, but also according to specific criteria within the field. The database MED_ALL is again used to demonstrate this operation.

Suppose, for instance, that a question has been raised regarding a plant that is probably endangered and could have a local name beginning with the letters math. First, load the database MED_ALL and operate in Table Format; then use the |Select| option to pick out Local Name. As the file contains over a hundred records, you are given the option of nominating the first few letters of the name. Accordingly, select |Yes| and type in the letters math and press Enter. Then click onto |CONTINUE| and a list of four names will appear, these being the only local names in the database which commence with the letters math. Select each of the four possibilities by responding |Yes| to all of them. Now click onto |Continue| and then |Esc| to complete the selection process.

The result will be found in SELFIL; make a copy of this (called, say, MATH_) and operate the new database in Record Format. You will see that two of the four plants selected are classified under the field Threat as Indeterminate. In this demonstration, these records can be excluded. Therefore click onto |Delete Record| when the records in question are on the screen. At this point the screen will indicate that four records still exist even though only records 1 and 4 can be viewed on the screen. However, as soon as |Exit| is selected the two unwanted records will be removed completely. On return to Record Format, the two selected records of the database should appear as follows:

Genus Species Local Threat Life Part Distrib.

Name Form

Eucomis autumnalis Mathunga,-u Declining G4 bulb cl

Aloe aristata Mathithibala,-u Rare & Vulnerable C4 whole plant ul

The approach given in this example could be used for other selections; for instance, identifying plants according to leaf characteristics, assuming suitable fields are present in the database.

7.7.7 Adding databases

This operation adds one database to another provided that both have exactly the same fields.

Following on from the example above, suppose that an extra plant record with a local name of Mabelejongosi,-u has to be added to MATH_. Exactly the same process (starting with MED_ALL) of initial selection can be used, except that in this case the first letters entered are mabe. There is only one record in the MED_ALL database with these first letters and once selected it will be stored in SELFIL.

It is possible to add the databases MATH_ and SELFIL (or better SELFIL copied to, say, MABE_) to each other as they contain identical fields, having been extracted in this case from the same parent database. To perform this operation, first click onto |Add Databases| on the Main menu. Then click onto |Continue| and select from the list MATH_ for the first database and SELFIL (or MABE_) for the second. The name ADDED can be given to the new database which will contain the three records, as shown below:

Genus Species Local name Threat Life Form Part Distribution

Eucomis autumnalis Mathunga,-u Declining G4 bulb cl

Aloe aristata Mathithibala,-u Rare & Vulnerable C4 whole plant ul

Eulophia cucullata Mabelejongosi,-u Declining G2 bulb cl