Mysql：从同一表中选择查询

Question

我想将不同的查询组合成一个字段并按字段分组。 当我分别执行查询时，我得到了所需的结果，但我无法将它们合并。我认为union或union all应该合并它们。

下面是查询。

(select cmb_region, count(*) as count1 
 from leases 
 where txt_contr_end <= CURDATE() 
 group by cmb_region) 
union 
(select cmb_region, count(*) as count2 
 from leases 
 where txt_contr_end >= CURDATE() 
 group by cmb_region);

这是我得到的结果：

+------------+--------+
| cmb_region | count1 |
+------------+--------+
| Central    |    648 |
| NGA        |    647 |
| NULL       |    140 |
| SGS        |      1 |
| Central    |    855 |
| NGA        |    855 |
| NULL       |      5 |
+------------+--------+

一切都一样。 第二个结果不存在。

Answer 1

您需要像这样的2个不同的列。

(select cmb_region, count(*) as count1, 0 as count2 
 from leases 
 where txt_contr_end <= CURDATE() 
 group by cmb_region) 
union 
(select cmb_region, 0 as count1, count(*) as count2 
 from leases 
 where txt_contr_end >= CURDATE() 
 group by cmb_region);

或者如果您在同一行中需要它们

 select cmb_region, 
        sum(CASE WHEN txt_contr_end <= CURDATE() THEN 1 ELSE 0 END) as count1,
        sum(CASE WHEN txt_contr_end >= CURDATE() THEN 1 ELSE 0 END) as count2 
 from leases 
 group by cmb_region