PostgreSQL中的IF ELSE

IF condition THEN
    statement1;
ELSE
    statement2;
END IF;

DO DECLARE
    input_string TEXT := 'Welcome to geek-docs.com';
BEGIN
    IF input_string LIKE '%geek-docs.com%' THEN
        RAISE NOTICE '字符串中包含geek-docs.com';
    ELSE
        RAISE NOTICE '字符串中不包含geek-docs.com';
    END IF;
END;

NOTICE:  字符串中包含geek-docs.com
DO

DO DECLARE
    num1 INT := 10;
    num2 INT := 5;
BEGIN
    IF num1>num2 THEN
        RAISE NOTICE 'num1大于num2';
    ELSE
        RAISE NOTICE 'num2大于num1';
    END IF;
END;

NOTICE:  num1大于num2
DO

NOTICE: 应用20%折扣后的价格为：80
DO