SQL basics

SQL execution diagnostic registers
If an SQL statement execution failed, error description can be found in the SQLCA.SQLCODE, SQLSTATE, STATUS and SQLERRMESSAGE predefined registers.

The SQLCA diagnostic record
The SQLCA variable is a predefined record containing SQL statement execution information.

SQL error identification
Identifying SQL exceptions in your programs with SQLCA.SQLCODE.

SQL interruption
Interrupting long running SQL queries, or waiting queries because data is locked.

Debugging SQL
Setting the FGLSQLDEBUG environment variable to print SQL debug info.

Cursors and connections
Understanding relation between database cursors and connections.

Implicit database connection
Understanding the implicit database connection with DATABASE instruction used before MAIN.

The database utility library
Purpose of the fgldbutl.4gl library.

Handling nested transactions
Manage nested transactions in different parts of a program.