SQL 在子查询上选择计数的服务器错误

Question

我正在尝试 select 计算查询中的行数 return。查询是

Select 
    a.itm_cd, max(b.doc_num) ,max(c.text) 
from 
    ist b, itm_trn a, ist_cmnt c  
where 
    a.ist_seq_num = b.ist_seq_num 
    and a.ist_seq_num = c.ist_seq_num  
    and a.ist_wr_dt = b.ist_wr_dt 
    and a.new_loc_cd  like 'BOX115' 
    and a.ITT_CD = 'XFR' and a.create_dt >'21-AUG-16' 
group by 
    a.itm_cd;

对于我 return 3 行的这个特定查询，我需要编写一个查询 return 有多少行 returned。

我已经试过了：

Select 
    count(*) 
from 
    (Select 
         a.itm_cd, max(b.doc_num), max(c.text) 
     from 
         ist b,itm_trn a, ist_cmnt c  
     where 
         a.ist_seq_num = b.ist_seq_num 
         and a.ist_seq_num = c.ist_seq_num  
         and a.ist_wr_dt = b.ist_wr_dt 
         and a.new_loc_cd  like 'BOX115' 
         and a.ITT_CD = 'XFR' 
         and a.create_dt > '21-AUG-16' 
     group by 
         a.itm_cd);

这会导致语法错误

Msg 102, level 15, state 1 line 1
Incorrect syntax near ')'.

我不确定我做错了什么，我有一个类似的 SQL 语句在 Oracle 中以这种方式工作，但没有找到我在 SQL 服务器中搞砸的地方。

更新：

根据我收到的第一个建议，我尝试了：

Select 
    count(*)  
from 
    (Select 
         a.itm_cd, max(b.doc_num), max(c.text)
     from 
         ist b, itm_trn a, ist_cmnt c 
     where 
         a.ist_seq_num = b.ist_seq_num 
         and a.ist_seq_num = c.ist_seq_num  
         and a.ist_wr_dt = b.ist_wr_dt 
         and a.new_loc_cd  like 'BOX115' 
         and a.ITT_CD = 'XFR' 
         and a.create_dt > '21-AUG-16' 
     group by 
         a.itm_cd) as T

错误 returned 是

Msg 8155, Level 16, State 2, Line 12
No column was specified for column 2 of 'T'.

Msg 8155, Level 16, State 2, Line 12
No column was specified for column 3 of 'T'.

Answer 1

根据错误消息，您应该为聚合列添加别名。像这样尝试，

SELECT count(*)
FROM (
    SELECT a.itm_cd
        ,max(b.doc_num) AS MaxDoc_num
        ,max(c.TEXT) AS MaxText
    FROM ist b
        ,itm_trn a
        ,ist_cmnt c
    WHERE a.ist_seq_num = b.ist_seq_num
        AND a.ist_seq_num = c.ist_seq_num
        AND a.ist_wr_dt = b.ist_wr_dt
        AND a.new_loc_cd LIKE 'BOX115'
        AND a.ITT_CD = 'XFR'
        AND a.create_dt > '21-AUG-16'
    GROUP BY a.itm_cd
    ) T

您可以使用此查询轻松找到计数。

SELECT count(DISTINCT a.itm_cd)
FROM ist b
    ,itm_trn a
    ,ist_cmnt c
WHERE a.ist_seq_num = b.ist_seq_num
    AND a.ist_seq_num = c.ist_seq_num
    AND a.ist_wr_dt = b.ist_wr_dt
    AND a.new_loc_cd LIKE 'BOX115'
    AND a.ITT_CD = 'XFR'
    AND a.create_dt > '21-AUG-16'

SQL 在子查询上选择计数的服务器错误

SQL Server error selecting count on a subquery

sql-server-2005