计算机英语中英对照：dBASEⅢ使用

Using dBASE 3

　　Suppose the mailing list stores customer infor-mation for a warehouse that distributes wholesalekitchen appliances. The warehouse would also have aseparate database for customer orders, which wouldinclude fields for customer number, merchandisenumber, price per unit, quantity ordered, and totalcost. The mailing list and customer order databasesare relational because they have the customer numberfield in common (Figure 5一I)．By searching for thecustomer number in the mailing list and matching it tothe customer number in the order form，the databasemanager can determine who the purchaser is andwhere the purchaser is located from one database,and what the purchaser ordered and the total cost ofthe purchase from the other database．A databasemanager that draws information from different data-baseslinked b）a common field is called a relationaldatabase manager. 　　
　　The 124 commands in the dBASE IIIprogramming language offer you a host of ways tomanage information. But among all these commands, you won't find a single command that creates a data-base, inputs the information into it, and prints thedatabase on the printer. In any application, youprobably won't be able to use only one command thatwill perform the entire task. Instead, you will have todivide the task into smaller chores that dBASE IIIcommands can handle．For example, to create a mail-ing list, you will need to perform the following steps
　　(1) Create the database structure
　　(2) Input information in the database
　　(3) Print the contents of the database

　　Most commands can be entered on the keyboardand dBASE III will execute them immediatelv. This is called immediate mode operation. It is possible to do all your work on a database in immediate mode,but there are drawbacks．The most important is that you have to remember the exact form, or syntax ofthe command some of which are complicated. A typ-ing error will result in the computer not accepting the command; and when you want to repeat an operation, you have to remember the list of commands and the sequence you have already used. Fortunately, dBASE Ⅲ can store your program on disk for reuse. when Storing your program on the computer, you still haveto type the commands correctly. you still have to usethe proper sequence, but you only have to do it once．if you frequently create databases，input information,and print the information, you could save yourselfwork by entering the operation only once on a fileand reusing it as needed.