OLE DB DECLARE and EXECUTE

PowerBuilder requires a declarative statement to identify the database stored procedure that is being used and to specify a logical name for the procedure. The logical name is used to reference the procedure in subsequent SQL statements.

The general syntax for declaring a procedure is:

DECLARE logical_procedure_name PROCEDURE FOR
   [RC=]procedure_name
   {@param1 = value [OUTPUT], @param2 = &
      value2[OUTPUT], ...}
   {USING transaction_object};

where logical_procedure_name can be any valid PowerScript identifier and procedure_name is the name of a stored procedure in the database.

The parameter references can take the form of any valid parameter string the database accepts. PowerBuilder inspects the parameter list format only for variable substitution.

You must use the reserved word OUTPUT or OUT to indicate an output parameter if you want to get the output parameter value. If the stored procedure has a return value and you want to get it, use the syntax "RC=procedure_name".  If the procedure has one or more result sets, only after all the result set has been retrieved can you get the output parameter or return value. The USING clause is required only if you are using a transaction object other than the default transaction object (SQLCA).

Example 1

Assume a stored procedure named proc1 is defined on the server. To declare proc1 for processing within PowerBuilder, enter:

DECLARE emp_proc PROCEDURE FOR proc1;

The procedure declaration is a nonexecutable statement, just like a cursor declaration. However, where cursors have an OPEN statement, procedures have an EXECUTE statement.

When an EXECUTE statement executes, the procedure is invoked. The EXECUTE refers to the logical procedure name, in this example emp_proc:

EXECUTE emp_proc;

Example 2

This example declares a stored procedure with two input and one output parameters:

DECLARE sp_duration PROCEDURE FOR pr_date_diff_prd_ken
   @var_date_1 = :ad_start,
   @var_date_2 = :ad_end,
   @rtn_diff_prd = :ls_duration OUTPUT;

If the stored procedure contains result sets, you must fetch the result sets first. If the stored procedure has a return value and you want to obtain it, use the format RC=procedure_name:

DECLARE sp_duration PROCEDURE FOR& 
      RC=pr_date_diff_prd_ken
   @var_date_1 = :ad_start,
   @var_date_2 = :ad_end,
   @rtn_diff_prd = :ls_duration OUTPUT;

See also

OLE DB EXECUTE