Question

在Access中我有四个表T1, T2, T3和T4，其中的字段为1到10.其中一个字段是＆＃34; Field1＆＃34;所以我有以下几点：

[T1].Field1, [T2].Field1, [T3].Field1, [T4].Field1

我想选择至少一个Field1相等的所有值。

换句话说，我想做一些像

这样的事情

SELECT Field1,
       Field2,
       Field4,
       Field5 
  FROM all the table before 
 WHERE [T1].Field1 = [T2].Field1 
    OR [T1].Field1 = [T3].Field1 
    OR [T1].Field1 = [T4].Field1 
    OR [T2].Field1 = [T3].Field1 
    OR [T2].Field1 = [T4].Field1 
    OR [T3].Field1 = [T4].Field1

-

我的主要困难是FROM部分，因为SELECT很好，我可以把所有我感兴趣的字段放在不同的表中，WHERE也应该没问题，因为我可以说，正如我上面报道的那样。问题是在Access中使用FROM命令选择数据。我相信它可以通过外部加入来完成，但我不知道如何实现它。

假设我有：

TABLE1
1 Field1: 0012
  Field2: TEST
  Field3: TEST3
2 Field1: 0010
  Field2: TEST
  Field3: TEST3

TABLE2
1 Field1: 0012
  Field2: TEST2
  Field3: TEST3
2 Field1: 0044
  Field2: TEST
  Field3: TEST3

TABLE3
1 Field1: 0012
  Field2: TEST2
  Field3: TEST3
2 Field1: 0044
  Field2: TEST
  Field3: TEST3

TABLE4
1 Field1: 0011
  Field2: TEST2
  Field3: TEST3
2 Field1: 0010
  Field2: TEST
  Field3: TEST3
3 Field1: 0044
  Field2: TEST2
  Field3: TEST3

此时我想生成输出

TABLE1.Field1 TABLE2.Field1 TABLE3.Field1 TABLE4.Field1 TABLE1.Field2 TABLE2.Field2 TABLE3.Field2 TABLE4.Field2

在这种情况下，第一行将是与Field1 0012相关联的一行：

0012 0012 0012 NULL TEST TEST2 TEST2 NULL

第二个到0010：

0010 NULL NULL 0010 TEST NULL NULL TEST

等等。你能帮我正式化我的想法吗？

非常感谢

Answer 1

首先将所有记录与UNION ALL粘在一起，保留表名。然后聚合每field1并使用传统聚合来获取单个字段。使用HAVING仅显示包含多个表条目的field1：

select
  max(iif(table_name = 'TABLE1', field1, null)) as table1_field1,
  max(iif(table_name = 'TABLE2', field1, null)) as table2_field1,
  max(iif(table_name = 'TABLE3', field1, null)) as table3_field1,
  max(iif(table_name = 'TABLE4', field1, null)) as table4_field1,
  max(iif(table_name = 'TABLE1', field2, null)) as table1_field2,
  max(iif(table_name = 'TABLE2', field2, null)) as table2_field2,
  max(iif(table_name = 'TABLE3', field2, null)) as table3_field2,
  max(iif(table_name = 'TABLE4', field2, null)) as table4_field2,
  max(iif(table_name = 'TABLE1', field3, null)) as table1_field3,
  max(iif(table_name = 'TABLE2', field3, null)) as table2_field3,
  max(iif(table_name = 'TABLE3', field3, null)) as table3_field3,
  max(iif(table_name = 'TABLE4', field3, null)) as table4_field3
from
(
  select 'TABLE1' as table_name, field1, field2, field3 from table1
  union all
  select 'TABLE2' as table_name, field1, field2, field3 from table2
  union all
  select 'TABLE3' as table_name, field1, field2, field3 from table3
  union all
  select 'TABLE4' as table_name, field1, field2, field3 from table4
) alldata
group by field1
having count(*) > 1;

访问：使用OR选择公共值

1 个答案: