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.