我有一个这样的SQL表:
| SomeID | OtherID | Data
+----------------+-------------+-------------------
| abcdef-..... | cdef123-... | 18,20,22
| abcdef-..... | 4554a24-... | 17,19
| 987654-..... | 12324a2-... | 13,19,20
是否有一个查询，我可以执行查询，如SELECT OtherID, SplitData where SomeID = 'abcdef-.......，返回单独的行，就像这样:
| OtherID | SplitData
+-------------+-------------------
| cdef123-... | 18
| cdef123-... | 20
| cdef123-... | 22
| 4554a24-... | 17
| 4554a24-... | 19
基本上把我的数据在逗号处分割成单独的行?
我知道将逗号分隔的字符串存储到关系数据库中听起来很愚蠢，但消费者应用程序中的正常用例使这种方法非常有用。
我不想在应用程序中进行拆分，因为我需要分页，所以我想在重构整个应用程序之前探索选项。
它是SQL Server 2008(非r2)。
DECLARE @id_list VARCHAR(MAX) = '1234,23,56,576,1231,567,122,87876,57553,1216';
DECLARE @table TABLE ( id VARCHAR(50) );
DECLARE @x INT = 0;
DECLARE @firstcomma INT = 0;
DECLARE @nextcomma INT = 0;
SET @x = LEN(@id_list) - LEN(REPLACE(@id_list, ',', '')) + 1; -- number of ids in id_list
WHILE @x > 0
BEGIN
SET @nextcomma = CASE WHEN CHARINDEX(',', @id_list, @firstcomma + 1) = 0
THEN LEN(@id_list) + 1
ELSE CHARINDEX(',', @id_list, @firstcomma + 1)
END;
INSERT INTO @table
VALUES ( SUBSTRING(@id_list, @firstcomma + 1, (@nextcomma - @firstcomma) - 1) );
SET @firstcomma = CHARINDEX(',', @id_list, @firstcomma + 1);
SET @x = @x - 1;
END;
SELECT *
FROM @table;
;WITH tmp(SomeID, OtherID, DataItem, Data) as (
SELECT SomeID, OtherID, LEFT(Data, CHARINDEX(',',Data+',')-1),
STUFF(Data, 1, CHARINDEX(',',Data+','), '')
FROM Testdata
WHERE Data > ''
)
SELECT SomeID, OtherID, Data
FROM tmp
ORDER BY SomeID
仅对上述查询进行了微小的修改…
当使用这种方法时，您必须确保您的值中没有包含非法XML - user1151923
我总是使用XML方法。确保使用VALID XML。我有两个函数在有效的XML和文本之间转换。(我倾向于去掉回车，因为我通常不需要它们。
CREATE FUNCTION dbo.udf_ConvertTextToXML (@Text varchar(MAX))
RETURNS varchar(MAX)
AS
BEGIN
SET @Text = REPLACE(@Text,CHAR(10),'');
SET @Text = REPLACE(@Text,CHAR(13),'');
SET @Text = REPLACE(@Text,'<','<');
SET @Text = REPLACE(@Text,'&','&');
SET @Text = REPLACE(@Text,'>','>');
SET @Text = REPLACE(@Text,'''',''');
SET @Text = REPLACE(@Text,'"','"');
RETURN @Text;
END;
CREATE FUNCTION dbo.udf_ConvertTextFromXML (@Text VARCHAR(MAX))
RETURNS VARCHAR(max)
AS
BEGIN
SET @Text = REPLACE(@Text,'<','<');
SET @Text = REPLACE(@Text,'&','&');
SET @Text = REPLACE(@Text,'>','>');
SET @Text = REPLACE(@Text,''','''');
SET @Text = REPLACE(@Text,'"','"');
RETURN @Text;
END;
可以使用以下函数提取数据
CREATE FUNCTION [dbo].[SplitString]
(
@RowData NVARCHAR(MAX),
@Delimeter NVARCHAR(MAX)
)
RETURNS @RtnValue TABLE
(
ID INT IDENTITY(1,1),
Data NVARCHAR(MAX)
)
AS
BEGIN
DECLARE @Iterator INT;
SET @Iterator = 1;
DECLARE @FoundIndex INT;
SET @FoundIndex = CHARINDEX(@Delimeter,@RowData);
WHILE (@FoundIndex>0)
BEGIN
INSERT INTO @RtnValue (data)
SELECT
Data = LTRIM(RTRIM(SUBSTRING(@RowData, 1, @FoundIndex - 1)));
SET @RowData = SUBSTRING(@RowData,
@FoundIndex + DATALENGTH(@Delimeter) / 2,
LEN(@RowData));
SET @Iterator = @Iterator + 1;
SET @FoundIndex = CHARINDEX(@Delimeter, @RowData);
END;
INSERT INTO @RtnValue (Data)
SELECT Data = LTRIM(RTRIM(@RowData));
RETURN;
END;
