我如何得到:
id Name Value
1 A 4
1 B 8
2 C 9
to
id Column
1 A:4, B:8
2 C:9
我如何得到:
id Name Value
1 A 4
1 B 8
2 C 9
to
id Column
1 A:4, B:8
2 C:9
当前回答
如果是SQL Server 2017或SQL Server Vnext, SQL Azure,您可以使用STRING_AGG如下所示:
SELECT id, STRING_AGG(CONCAT(name, ':', [value]), ', ')
FROM #YourTable
GROUP BY id
其他回答
这类问题在这里经常被问到,解决方案将在很大程度上取决于潜在的需求:
https://stackoverflow.com/search?q=sql+pivot
and
https://stackoverflow.com/search?q=sql+concatenate
通常,如果没有动态sql、用户定义函数或游标,就没有仅使用sql的方法来完成此任务。
当我尝试将Kevin Fairchild的建议转换为使用包含空格和编码的特殊XML字符(&,<,>)的字符串时,遇到了几个问题。
我的代码的最终版本(它没有回答最初的问题,但可能对某些人有用)看起来像这样:
CREATE TABLE #YourTable ([ID] INT, [Name] VARCHAR(MAX), [Value] INT)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (1,'Oranges & Lemons',4)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (1,'1 < 2',8)
INSERT INTO #YourTable ([ID],[Name],[Value]) VALUES (2,'C',9)
SELECT [ID],
STUFF((
SELECT ', ' + CAST([Name] AS VARCHAR(MAX))
FROM #YourTable WHERE (ID = Results.ID)
FOR XML PATH(''),TYPE
/* Use .value to uncomment XML entities e.g. > < etc*/
).value('.','VARCHAR(MAX)')
,1,2,'') as NameValues
FROM #YourTable Results
GROUP BY ID
DROP TABLE #YourTable
它没有使用空格作为分隔符并将所有空格替换为逗号,而是在每个值前附加一个逗号和空格,然后使用STUFF删除前两个字符。
XML编码由TYPE指令自动处理。
从http://groupconcat.codeplex.com安装SQLCLR聚合
然后你可以像这样写代码来得到你想要的结果:
CREATE TABLE foo
(
id INT,
name CHAR(1),
Value CHAR(1)
);
INSERT INTO dbo.foo
(id, name, Value)
VALUES (1, 'A', '4'),
(1, 'B', '8'),
(2, 'C', '9');
SELECT id,
dbo.GROUP_CONCAT(name + ':' + Value) AS [Column]
FROM dbo.foo
GROUP BY id;
不需要光标…while循环就足够了。
------------------------------
-- Setup
------------------------------
DECLARE @Source TABLE
(
id int,
Name varchar(30),
Value int
)
DECLARE @Target TABLE
(
id int,
Result varchar(max)
)
INSERT INTO @Source(id, Name, Value) SELECT 1, 'A', 4
INSERT INTO @Source(id, Name, Value) SELECT 1, 'B', 8
INSERT INTO @Source(id, Name, Value) SELECT 2, 'C', 9
------------------------------
-- Technique
------------------------------
INSERT INTO @Target (id)
SELECT id
FROM @Source
GROUP BY id
DECLARE @id int, @Result varchar(max)
SET @id = (SELECT MIN(id) FROM @Target)
WHILE @id is not null
BEGIN
SET @Result = null
SELECT @Result =
CASE
WHEN @Result is null
THEN ''
ELSE @Result + ', '
END + s.Name + ':' + convert(varchar(30),s.Value)
FROM @Source s
WHERE id = @id
UPDATE @Target
SET Result = @Result
WHERE id = @id
SET @id = (SELECT MIN(id) FROM @Target WHERE @id < id)
END
SELECT *
FROM @Target
使用Replace函数和FOR JSON PATH
SELECT T3.DEPT, REPLACE(REPLACE(T3.ENAME,'{"ENAME":"',''),'"}','') AS ENAME_LIST
FROM (
SELECT DEPT, (SELECT ENAME AS [ENAME]
FROM EMPLOYEE T2
WHERE T2.DEPT=T1.DEPT
FOR JSON PATH,WITHOUT_ARRAY_WRAPPER) ENAME
FROM EMPLOYEE T1
GROUP BY DEPT) T3
有关示例数据和更多方法,请点击这里