我想对一张表(test表)中的num(int)字段进行求平均直,但是不能使用AVG函数,请问怎么做? ----------------------------- 这样? select sum(num)/count(num) as [avg] from test 另外我还在问个问题,我想对两行数据中的同一个字段的直进行相加,这个字段是int型,请问该怎么做呢? ------------------------- select sum(num) as [sum] from test
declare @test table(id int identity,num int) insert @test(num) select 100 union all select 200 union all select 300--用avg時 select avg(num) as 平均值 from @test --不用avg時,覺得沒有必要這樣做 select sum(num)/count(num) as 平均值 from @test select sum(num) as total from @test where id=1 or id=2
或者是这样? 我想对一张表(test表)中的num(int)字段进行求平均直,但是不能使用AVG函数,请问怎么做? ------------------------- declare @sum int,@cou int select @sum = 0 ,@cou =0 select @sum=@sum +num ,@cou =@cou +1 from test select cast (@sum/@cou as decimal(9,2)) as [avg]另外我还在问个问题,我想对两行数据中的同一个字段的直进行相加,这个字段是int型,请问该怎么做呢? declare @sum int select @sum = 0 select @sum=@sum +num from test select cast (@sum as decimal(9,2)) as [sum]
能解释下这个是什么意思吗? select cast (@sum as decimal(9,2)) as [sum]
能解释下这个是什么意思吗? select cast (@sum as decimal(9,2)) as [sum] ---------------- 不好意思o,这个是复制上面的句子直接修改的... 这样就可以了 select @sum as [sum]
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这样?
select sum(num)/count(num) as [avg] from test
另外我还在问个问题,我想对两行数据中的同一个字段的直进行相加,这个字段是int型,请问该怎么做呢?
-------------------------
select sum(num) as [sum] from test
insert @test(num) select 100 union all select 200 union all select 300--用avg時
select avg(num) as 平均值 from @test --不用avg時,覺得沒有必要這樣做
select sum(num)/count(num) as 平均值 from @test select sum(num) as total from @test where id=1 or id=2
我想对一张表(test表)中的num(int)字段进行求平均直,但是不能使用AVG函数,请问怎么做?
-------------------------
declare @sum int,@cou int
select @sum = 0 ,@cou =0
select @sum=@sum +num ,@cou =@cou +1 from test
select cast (@sum/@cou as decimal(9,2)) as [avg]另外我还在问个问题,我想对两行数据中的同一个字段的直进行相加,这个字段是int型,请问该怎么做呢?
declare @sum int
select @sum = 0
select @sum=@sum +num from test
select cast (@sum as decimal(9,2)) as [sum]
select cast (@sum as decimal(9,2)) as [sum]
select cast (@sum as decimal(9,2)) as [sum]
----------------
不好意思o,这个是复制上面的句子直接修改的...
这样就可以了
select @sum as [sum]