MySQL

1、存储过程示例

CREATE TABLE p_user(
			id     INT PRIMARY KEY AUTO_INCREMENT,
      name   VARCHAR(10),
      sex    CHAR(2)
);
INSERT INTO p_user(name,sex) VALUES("A",'男');
INSERT INTO p_user(name,sex) VALUES("B",'女');
INSERT INTO p_user(name,sex) VALUES("C",'男');
#创建存储过程（查询得到男性或女性的数量），如果传入的是0就是女性否则是男性
DELIMITER $
CREATE PROCEDURE hw.get_user_count(IN sex_id INT,OUT user_count INT)
BEGIN
IF sex_id=0 THEN	
	 SELECT COUNT(*) FROM hw.p_user WHERE p_user.sex='女' INTO user_count;
ELSE
   SELECT COUNT(*) FROM hw.p_user WHERE p_user.sex='男' INTO user_count;
END IF;
END;
$

#调用存储过程
SET @user_count = 0;
CALL hw.get_user_count(2,@user_count);
SELECT @user_count;