存储过程P_GET_CLASS_NAME是根据输入的班级号判断班级名称

存储过程P_INSERT_STUDENT是接收输入的学生信息，最终将信息插入学生表。

DROP PROCEDURE IF EXISTS `P_GET_CLASS_NAME`;
CREATE PROCEDURE P_GET_CLASS_NAME(IN ID int,OUT NAME VARCHAR(50))
BEGIN
    IF(ID = 1) THEN 
          SET NAME = '一班';
    END IF;
    IF(ID = 2) THEN 
          SET NAME = '二班';
    END IF;
END;


DROP PROCEDURE IF EXISTS `P_INSERT_STUDENT`;
CREATE PROCEDURE P_INSERT_STUDENT(IN ID INT,IN NAME VARCHAR(10),IN CLASSNO INT,IN BIRTH DATETIME)
BEGIN
     SET @ID = ID;
     SET @NAME = NAME;
     SET @CLASSNO = CLASSNO;
     SET @BIRTH = BIRTH;
     SET @CLASSNAME = NULL;
     CALL P_GET_CLASS_NAME(@CLASSNO,@CLASSNAME);
     
     SET @insertSql = CONCAT('INSERT INTO TBL_STUDENT VALUES(?,?,?,?)');
     PREPARE stmtinsert FROM @insertSql;
     EXECUTE stmtinsert USING @ID,@NAME,@CLASSNAME,@BIRTH;
     DEALLOCATE PREPARE stmtinsert;
END;

CALL P_INSERT_STUDENT(1,'徐越',1,'2012-10-01 10:20:01');

在第二个存储过程中

①利用SET声明了参数，调用了第一个存储过程

②在第一个存储过程中的NAME参数是输出参数，所以@CLASSNAME这个参数在调用完第一个过程后就被附值

③最终利用CONCAT拼接SQL语句并传入参数执行SQL语句

CALL P_INSERT_STUDENT(1,'徐越',1,'2012-10-01 10:20:01');调用存储过程