Split delimited string value into rows

Question

Some external data vendor wants to give me a data field - pipe delimited string value, which I find quite difficult to deal with.

Without help from an application pr

Answer 1

Although your issue is probably long time resolved, I was looking for a solution to the very same problem you had. I solved it with the help of a procedure referenced here with slight adaptions to serve multi-byte characters (such as the German Umlauts) in the string by using CHAR_LENGTH() instead of LENGTH().

DELIMITER $$
    CREATE FUNCTION SPLIT_STRING(val TEXT, delim VARCHAR(12), pos INT) RETURNS TEXT
    BEGIN
        DECLARE output TEXT;
        SET output = REPLACE(SUBSTRING(SUBSTRING_INDEX(val, delim, pos), CHAR_LENGTH(SUBSTRING_INDEX(val, delim, pos - 1)) + 1), delim, '');
        IF output = '' THEN
            SET output = null;
        END IF;
        RETURN output;
    END $$

    CREATE PROCEDURE TRANSFER_CELL()
    BEGIN
        DECLARE i INTEGER;
        SET i = 1;
        REPEAT
            INSERT INTO NewTuple (id, value)
            SELECT id, SPLIT_STRING(value, '|', i)
            FROM Tuple
            WHERE SPLIT_STRING(value, '|', i) IS NOT NULL;
            SET i = i + 1;
        UNTIL ROW_COUNT() = 0
        END REPEAT;
    END $$
DELIMITER ;

CALL TRANSFER_CELL() ;

DROP FUNCTION SPLIT_STRING ;
DROP PROCEDURE TRANSFER_CELL ;