Tutorial Chapter 6: Append, Update, Delete
This program allows the user to create, modify and remove rows in
the customer database table. Embedded SQL statements
(UPDATE/INSERT/DELETE) are used to modify the SQL
table, based on the values stored in the program record.
Modules organization Importing modules IMPORT FGL instruction to simplify programming.Example: custmain.4gl MENU statement in the module custmain.4gl is modified to call functions for appending, updating, and deleting the rows in the customer table.Example: custquery.4gl CONSTRUCT query. In this section we describe the changes done from the custquery.4gl version of the previous chapter.Example: comutils.4gl comutils.4gl module implements a set of utility functions used by other modules.The custdata.4gl module custdata.4gl module implements customer table modification and utility functions.The INPUT statement INPUT statement allows the user to enter or change the values in a program record, which can then be used as the data for new rows in a database table, or to update existing rows.Updating Database Tables Appending/Updating a row INPUT statement provides control blocks to allow your program to initialize field contents and validate user input when adding or updating a row.Deleting a Row DELETE statement can be used to delete rows from the database table.