SQLPreview

Description

Occurs immediately before a SQL statement is submitted to the DBMS.

Event ID

Event ID	Objects
None	Transaction objects

Arguments

Argument	Description
sqlfunc	The SQLFunction system enumeration passed by value. This enumeration indicates the function that initiated database activity. Values for this enumeration are: SQLDBInsert! SQLDBUpdate!, SQLDBDelete!, SQLDBSelect!, SQLDBProcedure!, SQLDBRPC!, and SQLDBOthers!.
sqlsyntax	String by value. The full text of the SQL statement.

Returns

Long. Set the return code to affect the outcome of the event:

0 Continue processing
1 Stop processing

Usage

Use with embedded SQL This event is triggered before SQL statements are passed to the DBMS.

Use with DataWindow/DataStore When using this event of the Transaction object with a DataWindow that also defines a SQLPreview event, the DataWindow’s event is fired first. If the return value of DataWindow SQLPreview event is 0 (continue processing), the Transaction object’s SQLPreview event is triggered next.

Examples

Example 1

In this embedded SQL cursor example, the SQLPreview event is invoked just before the OPEN Emp_curs; statement is executed:

DECLARE Emp_cur CURSOR FOR SELECT employee.emp_number,
  employee.emp_name FROM employee 
WHERE employee.emp_salary > :Sal_var ;
OPEN Emp_curs ;

Example 2

In this dynamic SQL example, the SQLPreview event is invoked just before the EXECUTE DYNAMIC my_proc DESCRIPTOR SQLDA statement is executed:

PREPARE SQLSA FROM  "execute @rc = myproc @parm1=?,
   @parm2=? OUTPUT ";
DESCRIBE SQLSA INTO SQLDA ;
DECLARE my_proc DYNAMIC PROCEDURE FOR SQLSA ;
SetDynamicParm(SQLDA, 1, var1)
SetDynamicParm(SQLDA, 2, var2)
EXECUTE DYNAMIC my_proc DESCRIPTOR SQLDA ;