Mysql字符串拆分

2021-11-20 00:00:00 csv split mysql

可能的重复:
Mysql 可以拆分列吗?

我有一个字符串列和一个逗号分隔的列，如下所示

I have one string column and one comma separated column as below

例如，我有桌子，

Col1 | col2
1    | a,b,c
2    | d,e

从上面，我想要

Col1,Col2
1   ,a
1   ,b
1   ,c
2   ,d
2   ,e

如何实现这一点

这不是完全重复.

推荐答案

您可以使用存储过程来做到这一点

You can do this using a stored procedure

DELIMITER $$

CREATE FUNCTION strSplit(x VARCHAR(65000), delim VARCHAR(12), pos INTEGER) 
RETURNS VARCHAR(65000)
BEGIN
  DECLARE output VARCHAR(65000);
  SET output = REPLACE(SUBSTRING(SUBSTRING_INDEX(x, delim, pos)
                 , LENGTH(SUBSTRING_INDEX(x, delim, pos - 1)) + 1)
                 , delim
                 , '');
  IF output = '' THEN SET output = null; END IF;
  RETURN output;
END $$


CREATE PROCEDURE BadTableToGoodTable()
BEGIN
  DECLARE i INTEGER;

  SET i = 1;
  REPEAT
    INSERT INTO GoodTable (col1, col2)
      SELECT col1, strSplit(col2, ',', i) FROM BadTable
      WHERE strSplit(col2, ',', i) IS NOT NULL;
    SET i = i + 1;
    UNTIL ROW_COUNT() = 0
  END REPEAT;
END $$

DELIMITER ;

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