Using a Host Variable

You can declare the cursor variable in the PL/SQL host environment like an OCI or Pro C program. To use the cursor variable, you should pass it as a host variable to PL/SQL. In the Pro C illustration, you pass a host cursor variable and a selector to the PL/SQL block that opens the cursor variable for the chosen query:

EXEC SQL BEGIN DECLARE SECTION;

...

/* Declare host cursor variable. */

SQL_CURSOR generic_cv;

int choice;

EXEC SQL END DECLARE SECTION;

...

/* Initialize host cursor variable. */

EXEC SQL ALLOCATE :generic_cv;

...

/* Pass host cursor variable and selector to PL/SQL block. */

EXEC SQL EXECUTE

BEGIN

IF :choice = 1 THEN

OPEN :generic_cv FOR SELECT * FROM emp;

ELSIF :choice = 2 THEN

OPEN :generic_cv FOR SELECT * FROM dept;

ELSIF :choice = 3 THEN

OPEN :generic_cv FOR SELECT * FROM salgrade;

END IF;

END;

END-EXEC;

The Host cursor variables are well-suited with any query return type. They act just like the PL/SQL cursor variables.