怎么统计一个分组查询后的记录总数？
比如：
select a from t group by a
我要知道结果返回多少条记录
我这样写：
select count(a) from t group by a 为啥不行？
请指点，不甚感激！
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select a,count(a) from t group by a 为啥不行？
你前面没有a元素后面怎么group by
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ls的正解
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look
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declare @t table
(a int)
select a from @t group by a
select @@rowcount
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or
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select count(a) from (select a from @t group by a) b
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support Red_angelX
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select a, count(a) from t group by a
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select a, count(*) from t group by a
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jf
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select count(min_lvl)
from (
select min_lvl from jobs
group by min_lvl) tb
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select count(a) from (select a from t group by a)
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select count(1) from t group by a
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前面没有a元素
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比如 select a, b from t group by a 的结果如下：
a b
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a1 1
a2 3
a3 2
这时我要求返回记录总数，也就是3
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可以直接這麼寫
Select Count(Distinct a) From t