Question

我是SQL的新手，我有两个这样的表

tab1：

+---+---+
| ID|som|
+---+---+
|  e|  1|
|  d|  j|
|  c|  1|
|  b|  1|
|  a|  p|
+---+---+

tab2：

+------+---+
|SK_CUR|som|
+------+---+
|     b|  d|
|     a|  c|
|     a|  i|
+------+---+

，我只想计算两个表中字母的出现。因此输出应如下所示：

+------+---+
|    ID| oc|
+------+---+
|     a|  3|
|     b|  2|
|     c|  1|
|     d|  1|
|     e|  1|
+------+---+

Answer 1

我认为您只想要union all和group by：

select id, count(*)
from ((select id from t1) union all
      (select SK_CUR from t2)
     ) t
group by id;

Answer 2

尝试以下查询，

select ID , count(*) from (
select ID from tab1 where like '%[a-z]%'
union all
select som as ID from tab1 where som like '%[a-z]%'
union all
select SK_CUR as ID from tab2 where SK_CUR like '%[a-z]%'
union all
select som as ID from tab2 where som like '%[a-z]%')
group by ID

由于您只需要两个表的所有列中的字母，因此我使用了过滤器就像“％[a-z]％”

加入并计数发生

2 个答案: