从多个表中选择计数(*) [英] Select count(*) from multiple tables
本文介绍了从多个表中选择计数(*)的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
如何从两个具有结果的不同表格(称为tab1和tab2)中选择计数(*):
Count_1 Count_2
123 456
?
我尝试过:
Count_1 from schema.tab1 union all select count(*)Count_2 from schema.tab2
但我所有是:
Count_1
pre>
123
456
解决方案
SELECT(
SELECT COUNT(*)
FROM tab1
)AS count1,
(
SELECT COUNT(*)
FROM tab2
)AS count2
FROM dual
How can I select count(*) from two different tables (call them tab1 and tab2) having as result:
Count_1 Count_2 123 456
?
I've tried this:
select count(*) Count_1 from schema.tab1 union all select count(*) Count_2 from schema.tab2
But all I have is:
Count_1 123 456
解决方案SELECT ( SELECT COUNT(*) FROM tab1 ) AS count1, ( SELECT COUNT(*) FROM tab2 ) AS count2 FROM dual
这篇关于从多个表中选择计数(*)的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文