Tutorial Chapter 6: Add, Update and Delete

Entering data on a form: INPUT statement
The 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
The values of the program variables that have been input through the form can be used in SQL statements that update tables in a database.

Adding a new row
The INPUT statement provides control blocks to allow your program to initialize field contents and validate user input when adding a new row.

Updating an existing Row
Updating an existing row in a database table provides more opportunity for concurrency and consistency errors than inserting a new row. Use techniques shown in this section to help minimize the errors.

Deleting a Row
The SQL DELETE statement can be used to delete rows from the database table. The primary key of the row to be deleted can be obtained from the values in the program record.