mysql - 列中的 CONCAT 搜索

Question

SELECT
  People.Name, People.Secondname
  CONCAT(People.Name," ", People.Secondname)
FROM People, Shop, Circus
WHERE CONCAT(People.Name," ", People.Secondname) != Shop.Buyer 
  AND CONCAT(People.Name," ", People.Secondname) != Circus.Watcher

好的，这就是我的问题。有 2 列。我已将它们连接起来，并希望找到未去过商店和马戏团的人员名单。就像:我已经连接了全名 - “Jhon Jhonson”。他没有去过马戏团，也没有去过商店。所以我希望他能被展示出来。

因为我无法在这里发布图片，至少我可以获取我正在尝试制作的表格的链接... http://imm.io/1k5tJ 希望你能明白我想说的话。

Answer 1

尝试

SELECT
  People.Name, People.Secondname
  CONCAT(People.Name," ", People.Secondname)
FROM People left outer join Shop on CONCAT(People.Name," ", People.Secondname) = Shop.Buyer 
left outer join Circus on  CONCAT(People.Name," ", People.Secondname) = Circus.Watcher
where Shop.Buyer is null and  Circus.Watcher is null