字符串拆分只返回第一個條目

Question

我正在嘗試做一個內部使用過程只有它的一部分，你可以添加一個由逗號分隔的標籤的字符串。

SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 
CREATE PROCEDURE AddService 
    @ServiceName AS VARCHAR(MAX), 
    @Location AS VARCHAR(MAX), 
    @Description AS VARCHAR(MAX), 
    @PermissionType AS INT, 
    @Tags AS VARCHAR(MAX) 
AS 
BEGIN 
    DECLARE @ServiceId AS INT 

    INSERT INTO Services(NAME,LOCATION,DESCRIPTION,PERMISSIONTYPE) VALUES(@ServiceName,@Location,@Description,@PermissionType) 
    SET @ServiceId = (SELECT SCOPE_IDENTITY()) 

    DECLARE @TagSplit TABLE(ID INT IDENTITY(1,1),DATA VARCHAR(MAX)) 
    INSERT @TagSplit VALUES(SUBSTRING(@Tags,0,CHARINDEX(',',@Tags))) 

    WHILE EXISTS(SELECT * FROM @TagSplit) 
    BEGIN 
     DECLARE @TempId AS INT 
     DECLARE @Tag AS VARCHAR(MAX) 

     SET @TempId = (SELECT TOP 1 ID FROM @TagSplit) 
     SET @Tag = (SELECT TOP 1 DATA FROM @TagSplit) 

     INSERT INTO Tags VALUES(@ServiceId,@Tag) 

     DELETE FROM @TagSplit WHERE ID = @TempId 
    END 
END 
GO 

但是，當我看着我的「標籤」表中，給出的@Tags字符串「一些事」只能「部分」被添加，但不是「東西」。我想我可能會誤解如何在SQL中進行正確的字符串分割。

這部分不正常工作：

WHILE EXISTS(SELECT * FROM @TagSplit) 
BEGIN 
    DECLARE @TempId AS INT 
    DECLARE @Tag AS VARCHAR(MAX) 

    SET @TempId = (SELECT TOP 1 ID FROM @TagSplit) 
    SET @Tag = (SELECT TOP 1 DATA FROM @TagSplit) 

    INSERT INTO Tags VALUES(@ServiceId,@Tag) 

    DELETE FROM @TagSplit WHERE ID = @TempId 
END 

任何幫助嗎？

Answer 1

嘗試使用CSV分離器表值函數由傑夫MODEN

create function [dbo].[delimitedsplit8K] (
     @pstring varchar(8000) 
    , @pdelimiter char(1) 
) 
returns table with schemabinding as 
return 
    with e1(N) as (
    select 1 union all select 1 union all select 1 union all 
    select 1 union all select 1 union all select 1 union all 
    select 1 union all select 1 union all select 1 union all select 1 
) 
    , e2(N) as (select 1 from e1 a, e1 b) 
    , e4(N) as (select 1 from e2 a, e2 b) 
    , ctetally(N) as (
    select top (isnull(datalength(@pstring),0)) 
     row_number() over (order by (select null)) from e4 
) 
    , ctestart(N1) as (
    select 1 union all 
    select t.N+1 from ctetally t where substring(@pstring,t.N,1) = @pdelimiter 
) 
    , ctelen(N1,L1) as (
    select s.N1, 
     isnull(nullif(charindex(@pdelimiter,@pstring,s.N1),0)-s.N1,8000) 
    from ctestart s 
) 
select itemnumber = row_number() over(order by l.N1) 
     , item  = substring(@pstring, l.N1, l.L1) 
    from ctelen l 
; 
go 

分割字符串參考：

• Tally OH! An Improved SQL 8K 「CSV Splitter」 Function - Jeff Moden
• Splitting Strings : A Follow-Up - Aaron Bertrand
• Split strings the right way – or the next best way - Aaron Bertrand
• string_split() in SQL Server 2016 : Follow-Up #1 - Aaron Bertrand

那麼你的程序變成這樣：

CREATE PROCEDURE AddService 
    @ServiceName AS VARCHAR(MAX), 
    @Location AS VARCHAR(MAX), 
    @Description AS VARCHAR(MAX), 
    @PermissionType AS INT, 
    @Tags AS VARCHAR(MAX) 
AS 
BEGIN 
    set nocount, xact_abort on; 

    DECLARE @ServiceId AS INT; 

    INSERT INTO Services(NAME,LOCATION,DESCRIPTION,PERMISSIONTYPE) 
    VALUES(@ServiceName,@Location,@Description,@PermissionType) 

    SET @ServiceId = (SELECT SCOPE_IDENTITY()); 

    insert into tags 
    select @ServiceId, s.Item 
    from [dbo].[delimitedsplit8K](@Tags,',') s; 
end 
go