The IF-THEN statement of PL/SQL language has the same structure as the others equivalent procedural languages. The IF-THEN statement allows selective execution of actions based on the fulfillment of certain conditions.
If you want to execute a certain section of code only if a condition is true, you can use an IF-THEN statement.
IF condition THEN -- statements END IF;
You can also use an IF-THEN-ELSIF statement to check multiple conditions.
IF condition_1 THEN -- statement_1 ELSIF condition_2 THEN -- statement_2 END IF;
If you want to execute a certain section of code only if a condition is NOT true, you can use an IF-THEN-ELSE statement.
IF condition_1 THEN -- statement_1 ELSIF condition_2 THEN -- statement_2 ELSE -- statement_3 END IF;
You can use the CASE statement to select one of several alternative sections of code to execute.
CASE expression WHEN condition_1 THEN statement_1; WHEN condition_2 THEN statement_2; WHEN condition_3 THEN statement_3; ELSE statement_4; END CASE;