Pl/sql function body returning sql query

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PL/SQL Function Body Returning SQL Query

PL/SQL functions can be used to return SQL queries as results. This can be useful when you need to perform complex calculations or data manipulations before returning the final result.

Here’s an example of a PL/SQL function body returning an SQL query:

    
    CREATE OR REPLACE FUNCTION get_employee_details
        RETURN SYS_REFCURSOR
    IS
        result SYS_REFCURSOR;
    BEGIN
        OPEN result FOR
            SELECT employee_id, first_name, last_name, salary
            FROM employees;
        
        RETURN result;
    END;

In this example, we define a PL/SQL function called get_employee_details that returns a SYS_REFCURSOR type. The SYS_REFCURSOR is a special datatype in Oracle that can hold the result set of a SQL query.

Inside the function body, we declare a variable result of type SYS_REFCURSOR. We then open the result cursor by executing the SQL query SELECT employee_id, first_name, last_name, salary FROM employees.

Finally, we return the result cursor, which can be used to fetch the data from the SQL query.

Here’s how you can use the function in a SQL query:

    
    DECLARE
        emp_cursor SYS_REFCURSOR;
        emp_id NUMBER;
        emp_first_name VARCHAR2(50);
        emp_last_name VARCHAR2(50);
        emp_salary NUMBER;
    BEGIN
        emp_cursor := get_employee_details();
        
        LOOP
            FETCH emp_cursor INTO emp_id, emp_first_name, emp_last_name, emp_salary;
            EXIT WHEN emp_cursor%NOTFOUND;
            
            -- Do something with the fetched data
            -- For example, print the employee details
            DBMS_OUTPUT.PUT_LINE('Employee ID: ' || emp_id);
            DBMS_OUTPUT.PUT_LINE('First Name: ' || emp_first_name);
            DBMS_OUTPUT.PUT_LINE('Last Name: ' || emp_last_name);
            DBMS_OUTPUT.PUT_LINE('Salary: ' || emp_salary || CHR(10));
        END LOOP;
    END;

In the above example, we declare a variable emp_cursor of type SYS_REFCURSOR and call the get_employee_details function to assign the result set to the cursor. We then use a loop to fetch each row of data from the cursor until there are no more rows (EXIT WHEN emp_cursor%NOTFOUND). Inside the loop, we can perform any desired operations on the fetched data.

Note that the DBMS_OUTPUT.PUT_LINE procedure is used to print the employee details, but you can modify the code to suit your needs.


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