mysql 存储过程 动态sql例子

proc:BEGIN
    DECLARE _count INT DEFAULt 0;
    DECLARE _eventID INT DEFAULT 0;
    DECLARE _status INT DEFAULT 0;
    DECLARE _startTime VARCHAR(19) DEFAULT '';
    DECLARE _endTime VARCHAR(19) DEFAULT '';
    DECLARE _tblAccessLog VARCHAR(30) DEFAULT '';#插入日志的表,一个活动一张表

    #将局部变量转换成会话变量
    #动态sql语言只接受会话变量
    SET @iFieldID=iFieldID;
    SET @sUID=sUID;
    SET @sIP=sIP;
    SET @sCreateTime=sCreateTime;

    #判断字段状态
    SELECT event_id,`status` INTO _eventID,_status
    FROM portal_tongji_event_field
    WHERE id=iFieldID;

    IF _eventID=0 THEN
        SELECT -10001 AS retCode,'该字段不存在' AS retMsg;
        LEAVE proc;
    END IF;
    IF _status=2 THEN
        SELECT -10002 AS retCode,'该字段已禁用' AS retMsg;
        LEAVE proc;
    END IF;

    #判断活动状态
    SELECT COUNT(*),`status`,start_time,end_time INTO _count,_status,_startTime,_endTime
    FROM portal_tongji_event_info
    WHERE id=_eventID;

    IF _count=0 THEN
        SELECT -10003 AS retCode,'该活动不存在' AS retMsg;
        LEAVE proc;
    END IF;
    IF _status=2 THEN
        SELECT -10004 AS retCode,'该活动已禁用' AS retMsg;
        LEAVE proc;
    END IF;
    IF _startTime>CURDATE() THEN
        SELECT -10005 AS retCode,'活动未开始' AS retMsg;
        LEAVE proc;
    END IF;
    IF _endTime<CURDATE() THEN
        SELECT -10006 AS retCode,'活动已结束' AS retMsg;
        LEAVE proc;
    END IF;

    #判断日志表是否存在
    SET _tblAccessLog=CONCAT('portal_tongji_access_log_',_eventID);

    SELECT COUNT(*) INTO _count
    FROM information_schema.TABLES
    WHERE table_name =_tblAccessLog;

    IF _count=0 THEN
        SET @strSql=CONCAT('CREATE TABLE ',_tblAccessLog,' (`id` mediumint(8) unsigned NOT NULL AUTO_INCREMENT,`field_id` smallint(5) unsigned NOT NULL COMMENT \'统计字段ID\',`uid` varchar(24) NOT NULL COMMENT \'用户账号\',`ip` varchar(15) NOT NULL COMMENT \'用户IP\',`create_time` datetime NOT NULL COMMENT \'创建时间\',PRIMARY KEY (`id`),KEY `field_id` (`field_id`)) ENGINE=MyISAM AUTO_INCREMENT=1 DEFAULT CHARSET=gbk;');
        PREPARE stmt FROM @strSql;
        EXECUTE stmt;
        DEALLOCATE PREPARE stmt;
    END IF;

    #插入日志
    SET @strSql=CONCAT('INSERT ',_tblAccessLog,' VALUES(NULL,?,?,?,?);');
    PREPARE stmt FROM @strSql;
    EXECUTE stmt USING @iFieldID,@sUID,@sIP,@sCreateTime;
    DEALLOCATE PREPARE stmt;

    IF last_insert_id()>0 THEN
        SELECT 10000 AS retCode,'操作成功' AS retMsg;
    ELSE
        SELECT -10005 AS retCode,'插入失败' AS retMsg;
    END IF;
END

#输入参数:　　IN iFieldID tinyint(3),IN sUID varchar(24),IN sIP varchar(15),IN sCreateTime varchar(19)