Question

我创建了以下查询，选择了我需要的数据

SELECT par.wo, l.addr, eml.maildate, lp.workdate
FROM parsed AS par, emails AS eml, list AS l, locateparsed AS lp
WHERE par.status != 0 AND eml.id = par.origid AND par.wo = l.wo AND par.wo = lp.wo

是否可以让每个返回的行检查一个匹配的'wo'的“已完成”表，如果使用一个查询匹配则不输出它？

Answer 1

这正是为什么逗号分隔的表格让我非常恼火，你只是看不到连接类型使用的明显问题。试试这个：

SELECT
  par.wo,
  l.addr,
  eml.maildate,
  lp.workdate
FROM
  parsed AS par
  INNER JOIN emails AS eml      ON eml.id = par.origid
  INNER JOIN list AS l          ON par.wo = l.wo
  INNER JOIN locateparsed AS lp ON par.wo = lp.wo
  LEFT  JOIN completed          ON par.wo = completed.wo
WHERE
  par.status != 0 
  AND completed.wo IS NULL

将mysql select与table进行比较，仅使用不匹配的结果

1 个答案: