你可以用 Concat 在 MySQL ```
drop table if exists Demo;
CREATE TABLE Demo
(
ID INT AUTO_INCREMENT PRIMARY KEY,
channelid int,
Name VARCHAR(20)
);

INSERT INTO Demo(channelid, Name)VALUES
(1,'in'),(1,'out'),(1,'in'),(1,'out'),(2,'in'),(2,'out'),(1,'in'),(1,'out'),(1,'in'),(2,'out'),(2,'in'),(2,'out'),(2,'in'),(1,'in'),(1,'in');

查询

SELECT SQL_CALC_FOUND_ROWS
channelid,
group_concat ( concat(name,':',channelid) )
FROM Demo
group by channelid;

SELECT FOUND_ROWS();

看小提琴演奏的结果

请根据您的要求查找以下工作代码：

select tb.channelid, group_concat
(
  concat(tb.name,':',tb.MyCol2Count)

) as v1
from
(Select tbl.channelid,tbl.name,(LENGTH(tbl.val) - LENGTH(REPLACE(tbl.val,",","")) + 1) AS MyCol2Count
from 
(SELECT channelid, group_concat
(
  concat(name,':',channelid)

) as val,name
FROM Demo
group by channelid,Name) as tbl) as tb group by tb.channelid

您可以查看以下屏幕截图：http://springinfosoft.com/code/groupby_code.png

你可以用 GROUP_CONCAT 在子查询上，如下所示：

SELECT channelid, GROUP_CONCAT(
    CONCAT(direction, ': ', c)
    ORDER BY direction
    SEPARATOR ', '
) AS summary
FROM (
    SELECT channelid, direction, COUNT(*) AS c
    FROM t
    GROUP BY channelid, direction
) x
GROUP BY channelid

或者简单地使用条件聚合：

SELECT channelid, CONCAT_WS(', ',
    CONCAT('in: ',  COUNT(CASE WHEN direction = 'in'  THEN 1 END)),
    CONCAT('out: ', COUNT(CASE WHEN direction = 'out' THEN 1 END))
) AS summary
FROM t
GROUP BY channelid