★ APPLICATIONS ★ BUREAUTIQUE ★ DATABASE (c) GEMINI ★ |
| Gemini - Database | Applications Bureautique |
Anyone thinking of using the CPC464 in business, or just for recording a stamp collection, will be on the look out for an easy-to-use database program. A database in its simplest form is a computerised card index. You may enter the details of each 'card'and then browse through them, sort them into order, or search through them for a particular entry. To be of any real value, these jobs must be considerably easier on a computer database than with pen and paper. Gemini Marketing has had a lot of experience designing programs for home and small business use. They started with a range of programs for the BBC Model B and have since expanded to take in a range of home micros. Their database for the CPC464 is not a direct crib of a program for another machine, but is a development of earlier products, combining most of the essential features of a data storage system. The program is provided on cassette, although it's not protected and can be copied to disc if you want. On loading the tape you are presented with the main menu. This offers options, among other things, to search, sort and print records, to perform calculations on them and to summarise their contents. Before any of these functions can be used, however, you must first define the record card itself. You can choose either the 40 or 80 column modes to design and display your record, so you have plenty of space if your card contains a lot of information. The main restriction is not one of space on the screen, but rather the number of records your can fit into memory. In RAM The Gemini database is memory-based. This means it loads all the records in a particular file from cassette into memory in one go, and then manipulates them there. The advantages of this technique are that function like searching and sorting are performed very quickly. The disadvantage is that the size of the file is governed by the amount of available memory. The sample datafile supplied with the program is for a mailing list and can hold about 110 names and addresses. If each card holds less than this, more cards can be held on the file. You are completely free to position the fields on your card where you will. This is done by using the COPY key to place small white squares on the screen - one for each character you want in the field. To add titles to the fields, you simply move the cursor to the right spot and type them in. The whole process is very straightforward, and similar to that used by Gemini in their programs for other machines. When you've finished designing the card, you can set about entering your data. This again is a simple business, since each field is initially filled with the same small white squares, which you overwrite when you type in your entries. A count is kept at the top of the screen of the number of records you've added and the number remaining before you fill all available memory. These figures, along with the current record and the number of records found that match a given condition, are all headed with only a two character mnemonic. It would have been clearer to have had longer titles for these, even if it meant devoting two lines to them rather than one. Once you have entered all your data, there are a number of different things that this database will allow you to do with it. The 'find'option will search through your data looking for entries which match your given rule. These rules can be quite complex, and may include inequality and the Boolean functions 'AND' and 'OR', as well as a straight equality. Fields are specified by number, thus the formula 'F5>F4 AND F3= 'TEST' will match all the records where the contents of field 5 is greater than the contents of field 4 and field 3 contains the word 'TEST'. The matching records will be re-positioned at the beginning of the file. Sorting If you select the sort option, the program will perform a 'heap' sort, which is one of the faster methods, on any selected field. You can sort in either ascending or descending order. You can also perform calculations on any fields within a card. These may be simple totals or a more complex formula, defined in a similar way to the conditions for searching. This is a particularly powerful feature of the program. Although the whole package has been written in BASIC with machine code routines, it is commendably fast, and does have the advantage of being able to use any of the built-in mathematical and logical functions of the language. When it comes to printing the contents of your file, you can specify how you want the information laid out, but only to a limited extent. Gemini have produced a 'Report Generator' which will take data from the database and produce labels from it or incorporate it directly into a standard business letter. This package is extra, however, and costs as much as the database itself. Conclusion Overall, I was impressed with Gemini's database. Although it isn't as sophisticated as Campbell Software's fully machine coded Masterfile 464, it has the virtue of being simple to set up and easy to use -although at a similar price Dialog's slick DFM database includes the labels and standard letter function. The 20 page manual is well produced and describes the various functions concisely. Like any non-CP/M database the package is limited by being memory-bound, since to write a random-access database requires working in CP/M and then you have to think about a language other than Amstrad BASIC to write in. (Compiled Microsoft BASIC is one option). It's interesting to see what can be done without resorting to machine-code. With a program like a database, BASIC techniques, if well-used, can prove as effective as assembler albeit taking up rather more space. Perhaps the program is a bit pricey at £19.95; but if you want a good, robust package, you can't go far wrong with this one.
|
