Supplying Parameters Through a System Descriptor

You can create a system-descriptor area that describes the data type and memory location of one or more values and then specify the descriptor in the USING SQL DESCRIPTOR clause of the EXECUTE statement.

Each time that the EXECUTE statement is run, the values that the system-descriptor area describes are used to replace question-mark ( ? ) placeholders in the PREPARE statement.

The COUNT field corresponds to the number of dynamic parameters in the prepared statement. The value of COUNT must be less than or equal to the number of item descriptors that were specified when the system-descriptor area was allocated with the ALLOCATE DESCRIPTOR statement.

The following example shows how to use system descriptors to execute a prepared statement in ESQL/C:

EXEC SQL execute prep_stmt using sql descriptor 'desc1';