使用SQL Server,我如何分割一个字符串,以便我可以访问项目x?
拿一根“你好,约翰·史密斯”的绳子。我如何通过空格分割字符串并访问索引1应该返回“约翰”的项目?
使用SQL Server,我如何分割一个字符串,以便我可以访问项目x?
拿一根“你好,约翰·史密斯”的绳子。我如何通过空格分割字符串并访问索引1应该返回“约翰”的项目?
当前回答
如果你查看下面关于使用SQL分割字符串的SQL教程,你会发现许多函数可以用于在SQL Server上分割给定的字符串
例如,SplitAndReturnNth UDF函数可用于使用分隔符分割文本,并将第n块作为函数的输出返回
select dbo.SplitAndReturnNth('Hello John Smith',' ',2)
其他回答
我一直在使用vzczc的答案使用递归cte的一段时间,但一直想更新它来处理可变长度分隔符,也处理字符串与前驱和滞后“分隔符”,如当你有一个csv文件的记录,如:
“鲍勃”,“史密斯”桑尼维尔”,“CA”
或者当你处理如下所示的六部分fqn时。我广泛地使用这些来记录subject_fqn的审计,错误处理等,parsename只处理四个部分:
[netbios_name].[machine_name].[instance].[database].[schema].[table].[column]
这是我的更新版本,感谢vzczc的原始帖子!
select * from [utility].[split_string](N'"this"."string"."gets"."split"."and"."removes"."leading"."and"."trailing"."quotes"', N'"."', N'"', N'"');
select * from [utility].[split_string](N'"this"."string"."gets"."split"."but"."leaves"."leading"."and"."trailing"."quotes"', N'"."', null, null);
select * from [utility].[split_string](N'[netbios_name].[machine_name].[instance].[database].[schema].[table].[column]', N'].[', N'[', N']');
create function [utility].[split_string] (
@input [nvarchar](max)
, @separator [sysname]
, @lead [sysname]
, @lag [sysname])
returns @node_list table (
[index] [int]
, [node] [nvarchar](max))
begin
declare @separator_length [int]= len(@separator)
, @lead_length [int] = isnull(len(@lead), 0)
, @lag_length [int] = isnull(len(@lag), 0);
--
set @input = right(@input, len(@input) - @lead_length);
set @input = left(@input, len(@input) - @lag_length);
--
with [splitter]([index], [starting_position], [start_location])
as (select cast(@separator_length as [bigint])
, cast(1 as [bigint])
, charindex(@separator, @input)
union all
select [index] + 1
, [start_location] + @separator_length
, charindex(@separator, @input, [start_location] + @separator_length)
from [splitter]
where [start_location] > 0)
--
insert into @node_list
([index],[node])
select [index] - @separator_length as [index]
, substring(@input, [starting_position], case
when [start_location] > 0
then
[start_location] - [starting_position]
else
len(@input)
end) as [node]
from [splitter];
--
return;
end;
go
使用字符串和values()语句怎么样?
DECLARE @str varchar(max)
SET @str = 'Hello John Smith'
DECLARE @separator varchar(max)
SET @separator = ' '
DECLARE @Splited TABLE(id int IDENTITY(1,1), item varchar(max))
SET @str = REPLACE(@str, @separator, '''),(''')
SET @str = 'SELECT * FROM (VALUES(''' + @str + ''')) AS V(A)'
INSERT INTO @Splited
EXEC(@str)
SELECT * FROM @Splited
结果集。
id item
1 Hello
2 John
3 Smith
虽然类似于josejuan基于XML的回答,但我发现只处理一次XML路径,然后旋转稍微更有效:
select ID,
[3] as PathProvidingID,
[4] as PathProvider,
[5] as ComponentProvidingID,
[6] as ComponentProviding,
[7] as InputRecievingID,
[8] as InputRecieving,
[9] as RowsPassed,
[10] as InputRecieving2
from
(
select id,message,d.* from sysssislog cross apply (
SELECT Item = y.i.value('(./text())[1]', 'varchar(200)'),
row_number() over(order by y.i) as rn
FROM
(
SELECT x = CONVERT(XML, '<i>' + REPLACE(Message, ':', '</i><i>') + '</i>').query('.')
) AS a CROSS APPLY x.nodes('i') AS y(i)
) d
WHERE event
=
'OnPipelineRowsSent'
) as tokens
pivot
( max(item) for [rn] in ([3],[4],[5],[6],[7],[8],[9],[10])
) as data
8:30开始
select id,
tokens.value('(/n[3])', 'varchar(100)')as PathProvidingID,
tokens.value('(/n[4])', 'varchar(100)') as PathProvider,
tokens.value('(/n[5])', 'varchar(100)') as ComponentProvidingID,
tokens.value('(/n[6])', 'varchar(100)') as ComponentProviding,
tokens.value('(/n[7])', 'varchar(100)') as InputRecievingID,
tokens.value('(/n[8])', 'varchar(100)') as InputRecieving,
tokens.value('(/n[9])', 'varchar(100)') as RowsPassed
from
(
select id, Convert(xml,'<n>'+Replace(message,'.','</n><n>')+'</n>') tokens
from sysssislog
WHERE event
=
'OnPipelineRowsSent'
) as data
9点20分跑
下面是一个函数,它将完成问题的目标,即分割字符串并访问项目X:
CREATE FUNCTION [dbo].[SplitString]
(
@List VARCHAR(MAX),
@Delimiter VARCHAR(255),
@ElementNumber INT
)
RETURNS VARCHAR(MAX)
AS
BEGIN
DECLARE @inp VARCHAR(MAX)
SET @inp = (SELECT REPLACE(@List,@Delimiter,'_DELMTR_') FOR XML PATH(''))
DECLARE @xml XML
SET @xml = '<split><el>' + REPLACE(@inp,'_DELMTR_','</el><el>') + '</el></split>'
DECLARE @ret VARCHAR(MAX)
SET @ret = (SELECT
el = split.el.value('.','varchar(max)')
FROM @xml.nodes('/split/el[string-length(.)>0][position() = sql:variable("@elementnumber")]') split(el))
RETURN @ret
END
用法:
SELECT dbo.SplitString('Hello John Smith', ' ', 2)
结果:
John
如果你查看下面关于使用SQL分割字符串的SQL教程,你会发现许多函数可以用于在SQL Server上分割给定的字符串
例如,SplitAndReturnNth UDF函数可用于使用分隔符分割文本,并将第n块作为函数的输出返回
select dbo.SplitAndReturnNth('Hello John Smith',' ',2)