類似於MySQL中爆炸工作的函數

Question

MySQL中有任何函數用於爆炸某列的數據然後檢索它嗎？ 如果列數據是P：12，那麼數據可以在'：'上分解，然後讀取？

Answer 1

以下是有關SPLIT問題mysql的許多討論：

http://dev.mysql.com/doc/refman/5.0/en/string-functions.html

Answer 2

你可以寫在MYSQL分流功能檢查這個link

從鏈接

CREATE FUNCTION SPLIT_STR(
    x VARCHAR(255), 
    delim VARCHAR(12), 
    pos INT 
) 

RETURNS VARCHAR(255) 
RETURN REPLACE(SUBSTRING(SUBSTRING_INDEX(x, delim, pos), 
     LENGTH(SUBSTRING_INDEX(x, delim, pos -1)) + 1), 
     delim, ''); 

用法

SELECT SPLIT_STR(string, delimiter, position) 

例

SELECT SPLIT_STR('a|bb|ccc|dd', '|', 3) as third; 

+-------+ 
| third | 
+-------+ 
| ccc | 
+-------+ 

Answer 3

我解析使用while循環的串和插入拆分項到臨時表。這很複雜，但我複製並粘貼代碼，然後更改表名以提高可讀性。下面是一個例子來分析用戶ID的逗號分隔列表到一個臨時表：

CREATE PROCEDURE spParse 
(_UserList MEDIUMTEXT) 
BEGIN 
    DECLARE _Pos INT; 
    DECLARE _Start INT; 
    DECLARE _Item INT; 
    DECLARE _Length INT; 

    CREATE TEMPORARY TABLE IF NOT EXISTS TempUserList 
    (
     UserID INT 
    ); 

    SET _Length = LENGTH(_UserList); 
    SET _Pos = 1; 
    SET _Start = 1; 
    divide_loop:LOOP 
     IF _Pos > _Length Then 
      LEAVE divide_loop; 
     End If; 
     IF SUBSTRING(_UserList,_Pos,1) = ',' Then 
      IF _Pos - _Start > 0 Then 
       IF IsNumeric(SUBSTRING(_UserList,_Start,_Pos-_Start)) Then 
        SET _Item = CONVERT(SUBSTRING(_UserList,_Start,_Pos-_Start),Signed); 
        INSERT INTO TempUserList (UserID) 
        VALUES (_Item); 
       End If;     
      End If; 
      SET _Start = _Pos + 1; 
     End If; 
     SET _Pos = _Pos + 1; 
    END LOOP divide_loop; 
    IF _Start <= _Length Then 
     If IsNumeric(SUBSTRING(_UserList,_Start,_Length - _Start + 1)) Then 
      SET _Item = CONVERT(SUBSTRING(_UserList,_Start,_Length - _Start + 1),Signed);  
      INSERT INTO TempUserList (UserID) 
      VALUES (_Item); 
     End If; 
    End If; 

    SELECT UserID FROM TempUserList; 

    DROP TABLE TempUserList; 
END