Question

我有一张如下表所示的表格：

create table test
(
  cola varchar(10) 
)

插入一些数据：

insert into test values('a');
insert into test values('a');
insert into test values('a');
insert into test values('b');
insert into test values('b');
insert into test values('c');
insert into test values('d');
insert into test values('d');

我想显示列cola

中有多少组

预期结果：

TotalGroups   a    b    c    d 
--------------------------------
 4            3    2    1    2

Answer 1

试试这个，删除[和]以避免sql注入：

DECLARE @sql varchar(max) = 
       'SELECT (select count(distinct cola) from test) TotalGroups'

SELECT @sql += ',' +cast(count(*) as varchar(10)) + 
      '['+ replace(replace(cola, ']', ''), '[', '') + ']'
FROM TEST
GROUP BY cola
ORDER BY cola


EXEC(@sql)

结果：

Total_Groups  a  b  c  d
4             3  2  1  2

Answer 2

试试这个： -

SELECT count(distinct cola) AS Total_Groups, COUNT(CASE WHEN COLA = 'a' THEN 1 END) AS a,
                                             COUNT(CASE WHEN COLA = 'b' THEN 1 END) AS b,
                                             COUNT(CASE WHEN COLA = 'c' THEN 1 END) AS c,
                                             COUNT(CASE WHEN COLA = 'd' THEN 1 END) AS d                   
FROM TEST;

这是小提琴

http://sqlfiddle.com/#!2/fe5be/19

使用SQL Server 2008计算列中存在的组数

2 个答案: