解析郜燕(wx1110283)2023-06-09 15:33 select 6 union select 7 union select 8 union select 9 union select 10 union select 11

这是一个 SQL 查询语句，其目的是将数字 6 到 11 分别作为一行输出。SELECT 是用于从表中获取数据的 SQL 关键字，UNION 是用于合并结果集的关键字。

具体解析如下：

1. select 6：从一个虚拟表中选择数字 6，作为结果集的第一行。
2. union select 7：将数字 7 作为另一行添加到结果集中。
3. union select 8：将数字 8 作为另一行添加到结果集中。
4. union select 9：将数字 9 作为另一行添加到结果集中。
5. union select 10：将数字 10 作为另一行添加到结果集中。
6. union select 11：将数字 11 作为最后一行添加到结果集中。

因此，执行该查询语句后，结果集将包含六行数据，分别是数字 6 到 11。

相关问题

select count(1) from (select distinct unique_id_station from d_wx_expansion_oarea2023 dweo where 1 = 1 and unique_id_station is not null) as a union all select count(1) from (select distinct unique_id_station from d_wx_expansion_oarea2023 where 1 = 1 and is_pdcp_busy_week =1 and unique_id_station is not null) as aaa 将两条sql合成一条不使用UNION ALL

可以使用子查询和 CASE WHEN 语句将两条 SQL 合并成一条，如下所示：

SELECT 
    COUNT(DISTINCT CASE WHEN unique_id_station IS NOT NULL THEN unique_id_station END) as total_count,
    COUNT(DISTINCT CASE WHEN is_pdcp_busy_week = 1 AND unique_id_station IS NOT NULL THEN unique_id_station END) as pdcp_busy_count
FROM d_wx_expansion_oarea2023

这条 SQL 语句会返回两个列，分别为总数量和满足 `is_pdcp_busy_week = 1` 条件的数量。

select count(1)from (select distinct unique_id_station from d_wx_expansion_oarea2023 dweo where 1 = 1 and unique_id_station is not null and province_name ='河北省'and month_id ='202212' ) as a union all select count(1) from d_wx_expansion_oarea2023 where 1 = 1 and province_name ='河北省'and city_name ='邯郸市'and month_id ='202212' union all select count(1) from d_wx_expansion_oarea2023 where 1 = 1 and province_name ='河北省'and city_name ='邯郸市'and month_id ='202212' and is_pdcp_busy_week =1 union all select count(1)from(select distinct unique_id_station from d_wx_expansion_oarea2023 where 1 = 1 and province_name ='河北省' and city_name ='邯郸市'and month_id ='202212' and is_pdcp_busy_week =1 and unique_id_station is not null) as aaa将四个sql语句合成一个

SELECT
(SELECT COUNT(DISTINCT unique_id_station) FROM d_wx_expansion_oarea2023 WHERE province_name = '河北省' AND month_id = '202212' AND unique_id_station IS NOT NULL) AS cnt1,
(SELECT COUNT(*) FROM d_wx_expansion_oarea2023 WHERE province_name = '河北省' AND city_name = '邯郸市' AND month_id = '202212') AS cnt2,
(SELECT COUNT(*) FROM d_wx_expansion_oarea2023 WHERE province_name = '河北省' AND city_name = '邯郸市' AND month_id = '202212' AND is_pdcp_busy_week = 1) AS cnt3,
(SELECT COUNT(DISTINCT unique_id_station) FROM d_wx_expansion_oarea2023 WHERE province_name = '河北省' AND city_name = '邯郸市' AND month_id = '202212' AND is_pdcp_busy_week = 1 AND unique_id_station IS NOT NULL) AS cnt4;