INFORMIX-ESQL/C Programmer's Manual Using a System-Descriptor Area

How you determine the input parameters in the WHERE clause of a DELETE or UPDATE statement is very similar to how you determine them in the WHERE clause of a SELECT statement. For more information, see Handling a Parameterized SELECT Statement. The major differences between these two types of dynamic parameterized statements are as follows:

• You do not need to use a cursor to handle a DELETE or UPDATE statement. Therefore, you provide the parameter values from a system-descriptor area with the USING SQL DESCRIPTOR clause of the EXECUTE statement instead of the OPEN statement.
• You can use the DESCRIBE...USING SQL DESCRIPTOR statement to determine if the DELETE or UPDATE statement has a WHERE clause. For more information, see Checking for a WHERE Clause.