Difference between SQL and PL/SQL

SQL (Structured Query Language) is a standard database language used to create, maintain, and retrieve data from relational databases. PL/SQL (Procedural Language extension to SQL) extends SQL by adding procedural capabilities like variables, loops, conditions, and error handling.

SQL Example

SQL executes a single declarative statement at a time ?

-- SQL: single operation, declarative
SELECT name, salary
FROM employees
WHERE department = 'Engineering';

PL/SQL Example

PL/SQL can execute multiple operations with procedural logic ?

-- PL/SQL: procedural block with variables, loops, conditions
DECLARE
    v_name employees.name%TYPE;
    v_bonus NUMBER;
BEGIN
    FOR emp IN (SELECT name, salary FROM employees) LOOP
        IF emp.salary > 50000 THEN
            v_bonus := emp.salary * 0.10;
        ELSE
            v_bonus := emp.salary * 0.05;
        END IF;
        DBMS_OUTPUT.PUT_LINE(emp.name || ' bonus: ' || v_bonus);
    END LOOP;
END;

Key Differences

Conclusion

SQL is used for direct data manipulation with single declarative statements. PL/SQL extends SQL with procedural capabilities, allowing developers to write complex business logic with variables, loops, conditions, and error handling in a single executable block.