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
解析姓和名的简单解决方案
DECLARE @Name varchar(10) = 'John Smith'
-- Get First Name
SELECT SUBSTRING(@Name, 0, (SELECT CHARINDEX(' ', @Name)))
-- Get Last Name
SELECT SUBSTRING(@Name, (SELECT CHARINDEX(' ', @Name)) + 1, LEN(@Name))
在我的例子中(在许多其他人中似乎也是如此……),我有一个由一个空格隔开的姓和名列表。可以直接在选择语句中使用它来解析姓和名。
-- i.e. Get First and Last Name from a table of Full Names
SELECT SUBSTRING(FullName, 0, (SELECT CHARINDEX(' ', FullName))) as FirstName,
SUBSTRING(FullName, (SELECT CHARINDEX(' ', FullName)) + 1, LEN(FullName)) as LastName,
From FullNameTable
其他回答
从SQL Server 2016开始,我们使用string_split
DECLARE @string varchar(100) = 'Richard, Mike, Mark'
SELECT value FROM string_split(@string, ',')
通过delimeter函数得到字符串的n个部分:
create function GetStringPartByDelimeter (
@value as nvarchar(max),
@delimeter as nvarchar(max),
@position as int
) returns NVARCHAR(MAX)
AS BEGIN
declare @startPos as int
declare @endPos as int
set @endPos = -1
while (@position > 0 and @endPos != 0) begin
set @startPos = @endPos + 1
set @endPos = charindex(@delimeter, @value, @startPos)
if(@position = 1) begin
if(@endPos = 0)
set @endPos = len(@value) + 1
return substring(@value, @startPos, @endPos - @startPos)
end
set @position = @position - 1
end
return null
end
以及用法:
select dbo.GetStringPartByDelimeter ('a;b;c;d;e', ';', 3)
返回:
c
好吧,我的代码并不那么简单,但下面是我用来将逗号分隔的输入变量分割为单个值,并将其放入表变量中的代码。我相信您可以稍微修改一下,根据空格进行分割,然后对该表变量执行基本的SELECT查询以获得结果。
-- Create temporary table to parse the list of accounting cycles.
DECLARE @tblAccountingCycles table
(
AccountingCycle varchar(10)
)
DECLARE @vchAccountingCycle varchar(10)
DECLARE @intPosition int
SET @vchAccountingCycleIDs = LTRIM(RTRIM(@vchAccountingCycleIDs)) + ','
SET @intPosition = CHARINDEX(',', @vchAccountingCycleIDs, 1)
IF REPLACE(@vchAccountingCycleIDs, ',', '') <> ''
BEGIN
WHILE @intPosition > 0
BEGIN
SET @vchAccountingCycle = LTRIM(RTRIM(LEFT(@vchAccountingCycleIDs, @intPosition - 1)))
IF @vchAccountingCycle <> ''
BEGIN
INSERT INTO @tblAccountingCycles (AccountingCycle) VALUES (@vchAccountingCycle)
END
SET @vchAccountingCycleIDs = RIGHT(@vchAccountingCycleIDs, LEN(@vchAccountingCycleIDs) - @intPosition)
SET @intPosition = CHARINDEX(',', @vchAccountingCycleIDs, 1)
END
END
概念是差不多的。另一种选择是利用SQL Server 2005本身的. net兼容性。实际上,您可以在. net中编写一个简单的方法,将字符串分割,然后将其作为存储过程/函数公开。
下面是一个SQL UDF,它可以分割字符串并只抓取特定的部分。
create FUNCTION [dbo].[udf_SplitParseOut]
(
@List nvarchar(MAX),
@SplitOn nvarchar(5),
@GetIndex smallint
)
returns varchar(1000)
AS
BEGIN
DECLARE @RtnValue table
(
Id int identity(0,1),
Value nvarchar(MAX)
)
DECLARE @result varchar(1000)
While (Charindex(@SplitOn,@List)>0)
Begin
Insert Into @RtnValue (value)
Select Value = ltrim(rtrim(Substring(@List,1,Charindex(@SplitOn,@List)-1)))
Set @List = Substring(@List,Charindex(@SplitOn,@List)+len(@SplitOn),len(@List))
End
Insert Into @RtnValue (Value)
Select Value = ltrim(rtrim(@List))
select @result = value from @RtnValue where ID = @GetIndex
Return @result
END
declare @strng varchar(max)='hello john smith'
select (
substring(
@strng,
charindex(' ', @strng) + 1,
(
(charindex(' ', @strng, charindex(' ', @strng) + 1))
- charindex(' ',@strng)
)
))