A_ODBC_STRICT_EQUAL configuration variable

When Database Connectors for ODBC executes a START … KEY EQUAL keyval, the interface generates a SELECT statement to select all rows with a key equal to the key columns in keyval. When fetching the data, Database Connectors eventually detects that there is no more data. If A_ODBC_STRICT_EQUAL is set to TRUE at the time the START is executed, the interface returns the error END OF FILE (error 10) at this point. If A_ODBC_STRICT_EQUAL is set to FALSE (the default), Database Connectors for ODBC then generates a new SELECT statement to continue reading records until the end of the file rather than the subset of records represented by keyval, and these records may be discarded by the program. (Note that this is program-dependent behavior.) Setting A_ODBC_STRICT_EQUAL to TRUE causes the interface to stop reading records earlier, which can make SELECT statements generated by Database Connectors for ODBC more efficient.

A_ODBC_STRICT_EQUAL has these conditions:

A_ODBC_STRICT_EQUAL must be set to TRUE when the START is executed.
The START must be a KEY EQUAL start.
There must be no COMMITs between the START and the end of the file. Because most ODBC drivers close all cursors on COMMIT and ROLLBACK (according to the ANSI 92 SQL standard), the interface must regenerate a SELECT the first time it attempts to execute a READ NEXT after a COMMIT or ROLLBACK. For most drivers, this means that the 4GL_COMMIT_COUNT configuration variable should be set to -”, so that no COMMITs are issued by Database Connectors for ODBC. See 4GL_COMMIT_COUNT for additional information.
A_ODBC_STRICT_EQUAL is most useful with alternate keys that allow duplicates.

Note:

This same behavior can be accomplished with the 4GL_WHERE_CONSTRAINT, but using A_ODBC_STRICT_EQUAL requires less programming.

The default value is FALSE (or OFF, NO, or 0). This configuration variable can also take the value TRUE, ON, YES, or 1.