--1. 建立fn_split函式. ( 切分字串， 返回乙個列名為id的表 )
if exists(
select *
from dbo.sysobjects
where id = object_id('fn_split')
and (type = 'fn' or type = 'tf' or type = 'if')
)drop function fn_split
go
create function [dbo].[fn_split]
( @str varchar(max),
@separator varchar(10)
)returns table
as return
( --example: select id from fn_split('a,b,d,c',',')
select b.id
from (
(--a 的作用只是生成 'abd
c' 的xml格式的資料, 提供資料來源
select [value] = convert(xml, '' + replace(@str, @separator, '
') + '')
) a
(--b 的作用是將a中的 xml 資料的值列舉出來轉換成行
select id = n.v.value('.', 'varchar(100)') from a.[value].nodes('/v') n(v)
) b)
)go
/*
by 砸死牛頓的蘋果
qq 343774501
*/-- 輔助數字表(可單獨使用)
if object_id('getnums') is not null
drop function getnums
gocreate function [dbo].[getnums]
( @n int
)returns table
as return
with t1 as(
select 1 n union all select 1
),t2 as(
select 1 n
from t1,
t1 a,
t1 b,
t1 c
),t3 as(
select 1 n
from t2,
t2 a,
t2 b,
t2 c
),t4 as(
select 1 n
from t3,
t3 a
)select top(@n) row_number()over(
order by(
select 1
)) n
from t4
order by
ngo-- 字串分割函式
if object_id('fn_split') is not null
drop function fn_split
gocreate function fn_split
( @s nvarchar(max),
@split nvarchar(2)
)returns table
as return
with t0 as (
select substring(@s, n, 1)ch,n
from getnums(len(@s))
),t1 as(
select ch,
rid = n -row_number()over(order by n) + 1
from t0
where ch <> @split
) select rid,
keys = (
select '' + ch
from t1 b
where b.rid = a.rid for xml path('')
)from t1 a
group by
ridgo-- 舉例測試
select *
from fn_split('aaa,bb,cc,123', ',')
/*rid keys
1 aaa
2 bb
3 cc
4 123
*/
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