Question

我有三个表t1，t2和t2，所有三个表都有相同的字段名称，例如

ID
HOMEPHONE
办公电话
MobilePhone

我想用t1检查t2和t3中的事件。我提出了MySQL查询（下面），但是当我运行它时我得到一个空集，知道我确实在所有三个表中都有重复的电话号码：

SELECT t1.id, t1.HomePhone, t1.WorkPhone, t1.MobilePhone, 
(
SELECT COUNT(*) 
FROM t2 
WHERE t1.HomePhone = t2.HomePhone 
    AND 
        (t2.HomePhone IS NOT NULL OR t2.HomePhone != '')
    UNION 
    SELECT COUNT(*) 
    FROM t2 
    WHERE t1.WorkPhone = t2.WorkPhone 
        AND 
            (t2.WorkPhone IS NOT NULL OR t2.WorkPhone != '')
        UNION 
    SELECT COUNT(*)  
    FROM t2 
    WHERE t1.MobilePhone = t2.MobilePhone 
        AND 
            (t2.MobilePhone IS NOT NULL OR MobilePhone != '')
) AS Countt2,
(
SELECT COUNT(*) 
FROM t3 
WHERE t1.HomePhone = t3.HomePhone 
    AND 
        (t3.HomePhone IS NOT NULL OR t3.HomePhone != '')
    UNION 
    SELECT COUNT(*) 
    FROM t3 
    WHERE t1.WorkPhone = t3.WorkPhone 
        AND 
            (t3.WorkPhone IS NOT NULL OR t3.WorkPhone != '')
        UNION 
    SELECT COUNT(*)  
    FROM t3 
    WHERE t1.MobilePhone = t3.MobilePhone 
        AND 
        (t3.MobilePhone IS NOT NULL  OR MobilePhone != '')
) AS Countt3 
FROM t1 
WHERE 
(t1.HomePhone IS NOT NULL OR t1.HomePhone != '') 
AND (t1.WorkPhone IS NOT NULL OR t1.WorkPhone != '')
AND (t1.MobilePhone IS NOT NULL OR t1.MobilePhone != '')

我在这里做错了什么？

Answer 1

前提：复制被定义为所有4个字段MATCH。因此，通过联合所有表并“计算它们＆gt; 1然后您将识别重复项。而groupConcat列出具有重复的表。

SELECT count(B.src), B.ID, B.HomePhone, B.WorkPHone, B.MobilePHone, 
    group_Concat(B.SRC) as TablesDupIN 
FROM (
(SELECT 't1'  as SRC, id, HomePhone, WorkPhone, MobilePhone FROM T1)
UNION ALL 
(SELECT 'T2', id, HomePhone, WorkPhone, MobilePhone FROM T2)
UNION ALL 
(SELECT 'T3', id, HomePhone, WorkPhone, MobilePhone FROM T3)) B
GROUP BY ID, HomePhone, WorkPhone, MobilePhone
HAVING count(*) > 1

union all返回每个表中的所有记录，但不会消除重复项。只是联盟会删除重复。 t1，t2，t3成一个临时表。我们可以从ID，HomePHone，WorkPhone和MobilePhone的临时表分组中进行选择。假设需要所有4个字段来确定重复。如果不是这种情况，您可以删除字段ID，如果它只是所有必须相同的电话。通过对结果进行分组，我们将其组合为ID，家庭电话，工作电话和移动电话等行。我使用'T1'，'T2'来识别具有重复的表格，副本在ID上，以及TalesDupIn中列出的表格中的3个电话号码。

结果将类似于

2 4 555-5555 555-5555 555-5555 (t1,t2)
2 5 666-6666 666-6666 666-6666 (t1,t3)
3 7 777-7777 777-7777 777-7777 (t1,t2,t3)
2 8 888-8888 888-8888 888-8888 (t2,t3)

这意味着在表1和表2中都找到了ID 4 ID 5见表1和表3 但副本是根据所有4个字段MATCHING ID + 3手机确定的。 IF ID不是副本的一部分，它可以从select和group by中删除，作为group_Concat（ID）添加，并且与tablesDupIn结合将告诉您所涉及的ID和表。根据您打算如何处理结果，这可能有益或无效......

Answer 2

您可以在这些

之间使用OR代替AND

   AND t3.HomePhone IS NOT NULL 
   AND t3.HomePhone != ''

像那样

    AND (t3.HomePhone IS NOT NULL 
         OR t3.HomePhone != '')

在所有查询中使用OR进行更改

Answer 3

SELECT 
  COUNT(DISTINCT t1.id)
  COUNT(DISTINCT t2.id)
  COUNT(DISTINCT t3.id)
FROM t1
LEFT JOIN t2 ON
  (t1.HomePhone=t2.HomePhone AND t1.HomePhone IS nOT NULL)
  OR (t1.WorkPhone=t2.WorkPhone AND t1.WorkPhone IS nOT NULL)
  OR (t1.MobilePhone=t2.MobilePhone AND t1.MobilePhone IS nOT NULL)
LEFT JOIN t3 ON
  (t1.HomePhone=t3.HomePhone AND t1.HomePhone IS nOT NULL)
  OR (t1.WorkPhone=t3.WorkPhone AND t1.WorkPhone IS nOT NULL)
  OR (t1.MobilePhone=t3.MobilePhone AND t1.MobilePhone IS nOT NULL)

MySQL：使用多个字段检查多个表的出现次数

3 个答案:

结果将类似于