Ntext字段拆分处理

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[p_split]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
drop procedure [dbo].[p_split]
GO

/*--Ntext字段拆分处理

 按指定的分隔符,将 ntext 字段拆分成多条记录
 注意:处理过程固定以名为id的int型字段为主键
 如果不满足这个条件,则要对应的修改存储过程

--邹建 2004.07(引用请保留此信息)--*/

/*--调用示例

 --测试数据
 create table tb(id int identity(1,1),content ntext)
 insert tb select '001,002'
 union all select '001,002,003,004,005,006,007,008,009,010'
 union all select replicate('001,002,003,004,005,006,007,008,009,010',8000)

 --调用存储过程,进行拆分
 exec p_split 'tb','content',',','id=3'

 drop table tb
--*/

create proc p_split
@tbname sysname,  --要处理的表名
@fdname sysname,  --text/ntext字段名
@splitchar nvarchar(10)=',',--拆分的字符串分隔符
@where nvarchar(1000)=''--要处理的记录的条件
as
if isnull(@splitchar,'')='' set @splitchar=','

declare @s nvarchar(4000)
set @s='
create table #t(id int identity(1,1),re nvarchar(50))
declare @id int,@ptr varbinary(16)
declare @s nvarchar(4000),@i int,@j int
declare @sp1 varchar(10),@step int

select @sp1=reverse(@splitchar),@step=len(@splitchar)

declare tb cursor local for
select id,s=substring(['+@fdname+'],1,4000)
from ['+@tbname+']
where datalength(['+@fdname+'])>0 
'+case isnull(@where,'') when '' then ''
 else ' and('+@where+')' end+'

open tb
fetch tb into @id,@s
while @@fetch_status=0
begin
 set @i=1
 while @s<>''''
 begin
  if len(@s)=4000
   select @j=4000-charindex(@sp1,reverse(@s))
    ,@i=@i+@j+@step
    ,@s=left(@s,@j)
  else
   select @i=@i+4000,@j=len(@s)
  insert #t select substring(@s,id,charindex(@splitchar,@s+@splitchar,id)-id)
  from 序数表
  where id<=@j+@step and charindex(@splitchar,@splitchar+@s,id)-id=0
  select @s=substring(['+@fdname+'],@i,4000)
  from ['+@tbname+']
  where id=@id
 end

 fetch tb into @id,@s
end
close tb
deallocate tb
select * from #t
'
exec sp_executesql @s
 ,N'@splitchar nvarchar(10)'
 ,@splitchar
go

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