拆分字符串函数

本函数可以将“目标字符串”以“指定字符串”进行拆分，并通过表结构返回结果。

在SQL Service中的代码如下：

 1 CREATE FUNCTION [dbo].[fnSPLIT]
 2 (
 3     @sInputString varchar(8000) 
 4     , @sSplitChar varchar(10)
 5 )RETURNS @tbl_List TABLE (SEQ INT IDENTITY(1,1),COD varchar(8000) )
 6 AS
 7 
 8 BEGIN
 9     DECLARE @lInputStringLength Int ,
10             @lPosition Int ,
11             @lSplitChar Int 
12 
13     SET @lInputStringLength = LEN ( @sInputString )
14     SET @lPosition=1
15     SET @lSplitChar=1
16 
17     WHILE @lPosition <= @lInputStringLength
18         BEGIN
19             SET @lSplitChar = CHARINDEX ( @sSplitChar , @sInputString , @lPosition)
20             IF @lSplitChar = 0
21                 BEGIN
22                     INSERT @tbl_List (COD )
23                     SELECT SUBSTRING( @sInputString , @lPosition ,1+ @lInputStringLength - @lPosition)
24                     SET @lPosition= @lInputStringLength + 1
25                 END
26             ELSE
27                 BEGIN
28                     INSERT @tbl_List ( COD )
29                     SELECT SUBSTRING( @sInputString , @lPosition , @lSplitChar - @lPosition)
30                     SET @lPosition = @lSplitChar+1
31         END
32     END
33     
34     DELETE @tbl_List WHERE RTRIM(COD)=''
35 
36     RETURN
37 END

返回结果：

SELECT * FROM dbo.fnSPLIT('我的未来不是梦,我的心跟着希望在动',',')

在Oracle中的代码如下：

 1 --在Type中的代码：
 2 CREATE OR REPLACE TYPE str_split IS TABLE OF VARCHAR2 (4000);
 3 
 4 --在Function中的代码：
 5 CREATE OR REPLACE FUNCTION fnSPLIT
 6 (
 7     P_InputString IN VARCHAR2, 
 8     P_Flag IN VARCHAR2
 9 )
10     RETURN str_split 
11     PIPELINED
12 AS
13     v_length   NUMBER := LENGTH(P_InputString);
14     v_start    NUMBER := 1;
15     v_index    NUMBER;
16 BEGIN
17     WHILE(v_start <= v_length)
18     LOOP
19         v_index := INSTR(P_InputString, P_Flag, v_start);
20 
21         IF v_index = 0
22         THEN
23             PIPE ROW(SUBSTR(P_InputString, v_start));
24             v_start := v_length + 1;
25         ELSE
26             PIPE ROW(SUBSTR(P_InputString, v_start, v_index - v_start));
27             v_start := v_index + 1;
28         END IF;
29     END LOOP;
30 
31     RETURN;
32 END fnSPLIT;

返回结果：

1 select * from (select rownum rn,t.* from table(fnSPLIT('我的未来不是梦,我的心跟着希望在动',',')) t)

将行转为列显示：

1 select a.column_value a,b.column_value b from 
2   (select * from (select rownum column_id,t.* from table(fnSPLIT('我的未来不是梦,我的心跟着希望在动',',')) t)) a,
3   (select * from (select rownum column_id,t.* from table(fnSPLIT('我的未来不是梦,我的心跟着希望在动',',')) t)) b
4 where a.column_id=1 and b.column_id=2