Mysql字段拼接，字符包含

字段拼接

• CONCAT(str1,str2,…) 拼接的字符串中有一个是Null，那么返回结果就是Null

  SELECT CONCAT(service_id,service_name)as id_name FROM t_sc_service;
  

• CONCAT_WS(separator,str1,str2,…) 拼接的字符串中有Null，返回结果也不会是Null

  SELECT CONCAT_WS('-',service_id,service_name)as id_name FROM t_sc_service;
  

• GROUP_CONCAT(expr1,expr2) 一对多关系中

  SELECT service_id,GROUP_CONCAT(service_name)as id_name FROM t_sc_service 
  GROUP BY service_id;
  

字段判断字符包含

• LIKE "%666%"
• FIND_IN_SET('666',name)
• LOCATE('666',name)>0

行转列，列转行

https://cloud.tencent.com/developer/article/1533688
https://www.w3xue.com/exp/article/201812/12440.html
https://zhuanlan.zhihu.com/p/139087541