Frankenstein_的博客

sql 语句拼写 <select id="findByCardBeaconNo" resultType="com.jxkj.arithmetic.entity.CardRecord"> select cr.id, cr.worker_id,cr.entity_type,cr.car_id,car_.car_no as carNo,wor_.name as workerName,c.beacon_no as beaconNo from card_record cr left j

1.最简单的问题在配置连接URL时添加?characterEncoding=utf8(原始配置信息)spring: datasource: url: jdbc:mysql://127.0.0.1:3306/test?serverTimezone=Asia/Shanghai username: root password: 654321 driver...

-- 正数时： 截取字符串中逗号',' 第一次出现左边的字符串 select SUBSTRING_INDEX(telephone,',', 1) as functionA from user-- 负数时： 截取字符串中逗号',' 最后一次出现右边的字符串 select SUBSTRING_INDEX(telephone,',', -1) as functionA from ...

三张表同时删除 project_id 为指定相同的值SQL 语句DELETE engineering_subcontractor,project_engineering,user_project from engineering_subcontractor LEFT JOIN project_engineering ON engineering_subcontractor.p...