11存储过程

CREATE PROCEDURE p1() 
BEGIN
    INSERT INTO goods VALUES(null,‘寒舍‘,50);    
    SELECT * FROM goods;
END

CALL p1();

#入参IN、出参OUT、出入参OUTIN
CREATE PROCEDURE p2(IN i INT,INOUT names VARCHAR(50)) 
BEGIN
    UPDATE goods SET name=names WHERE id=i;
    SELECT names;
END

SET @names=‘大鹅‘;
CALL p2(4,@names);

SELECT 要查询的值 INTO 要赋的值 FROM ...

CREATE PROCEDURE p3(IN flag CHAR(5),IN nums INT)
BEGIN
    IF flag=‘true‘ THEN SELECT * FROM goods WHERE num<nums;
    ELSEIF flag=‘false‘ THEN SELECT * FROM goods WHERE num>nums;
    ELSE SELECT * FROM goods;
    END IF;
END 

CALL p3(‘false‘,20);

#计算1到100的和
CREATE PROCEDURE p4(IN n INT,OUT m INT)
BEGIN
    DECLARE i INT DEFAULT 0;
    DECLARE sums INT;
    SET sums=0;
    WHILE i<=n DO
        SET sums=sums+i;
        SET i=i+1;
    END WHILE;
    SET m=sums;
END