mysql - msyql纵表转化横表问题

问题描述

构造表sql语句：

DROP TABLE IF EXISTS `hr_new_sign_activities_field_data`;CREATE TABLE `hr_new_sign_activities_field_data` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT, `field_id` int(11) unsigned NOT NULL DEFAULT ’0’ COMMENT ’字段ID’, `value` varchar(255) DEFAULT NULL COMMENT ’提交过来的数据’, `acitvity_info_id` int(11) NOT NULL DEFAULT ’0’ COMMENT ’表hr_new_sign_activities_info的自增ID’, PRIMARY KEY (`id`), KEY `acitvity_info_id` (`acitvity_info_id`)) ENGINE=InnoDB AUTO_INCREMENT=27 DEFAULT CHARSET=utf8 COMMENT=’用户提交的表单数据----这个主要是存储的后台设置的字段，用户提交的字段数据’;-- ------------------------------ Records of hr_new_sign_activities_field_data-- ----------------------------INSERT INTO `hr_new_sign_activities_field_data` VALUES (’6’, ’38’, ’我的企业’, ’5’);INSERT INTO `hr_new_sign_activities_field_data` VALUES (’7’, ’39’, ’13985623562’, ’5’);INSERT INTO `hr_new_sign_activities_field_data` VALUES (’8’, ’40’, ’13985623562@qq.com’, ’5’);INSERT INTO `hr_new_sign_activities_field_data` VALUES (’15’, ’38’, ’我的企业哈’, ’8’);INSERT INTO `hr_new_sign_activities_field_data` VALUES (’16’, ’39’, ’13652356524’, ’8’);INSERT INTO `hr_new_sign_activities_field_data` VALUES (’17’, ’40’, ’wangjian@shixiba.com’, ’8’);INSERT INTO `hr_new_sign_activities_field_data` VALUES (’18’, ’38’, ’sasassasasa’, ’9’);INSERT INTO `hr_new_sign_activities_field_data` VALUES (’19’, ’39’, ’13985236523’, ’9’);INSERT INTO `hr_new_sign_activities_field_data` VALUES (’20’, ’40’, ’13985236523@qq.com’, ’9’);INSERT INTO `hr_new_sign_activities_field_data` VALUES (’24’, ’38’, ’我速度1’, ’11’);INSERT INTO `hr_new_sign_activities_field_data` VALUES (’25’, ’39’, ’13562354125’, ’11’);INSERT INTO `hr_new_sign_activities_field_data` VALUES (’26’, ’40’, ’1253652361@qq.com’, ’11’);

我现在的数据表是这样的我现在期望转化为目前我的sql语句是这样的

select acitvity_info_id , CASE value when ’38’ then value else ’’ end as field_38, CASE value when ’39’ then value else ’’ end as field_39 , CASE value when ’40’ then value else ’’ end as field_40 from hr_new_sign_activities_field_data where acitvity_info_id in (5,8,9 , 11) GROUP BY acitvity_info_id

sql语句的效果如下：

我期望的最终效果如下：

问题解答

已经找到解决办法了

select m.acitvity_info_id ,CASE m.value when ’38’ then m.value else (select value from hr_new_sign_activities_field_data where acitvity_info_id =m.acitvity_info_id and field_id=38) end as field_38, CASE value when ’39’ then value else (select value from hr_new_sign_activities_field_data where acitvity_info_id =m.acitvity_info_id and field_id=39) end as field_39 , CASE value when ’40’ then value else (select value from hr_new_sign_activities_field_data where acitvity_info_id =m.acitvity_info_id and field_id=40) end as field_40 from hr_new_sign_activities_field_data m where acitvity_info_id in (5,8,9 , 11) GROUP BY acitvity_info_id