MySQL use ExtractValue(XML, 'Value/Values') to get all multiple values (split one column into rows)

Question

I have a non-normal field containing multiple values because it is Xml data that wasn\'t intended to be queried, until now. Can MySQL split this xml column into multiple row

Answer 1

No. You must solve this just like other mysql split column problems.

• Can MySQL split a column?
• Mysql string split

I.e. Specifically based on this answer

DROP FUNCTION IF EXISTS STRSPLIT;
DELIMITER $$
CREATE FUNCTION STRSPLIT($Str VARCHAR(20000), $delim VARCHAR(12), $pos INTEGER) 
    RETURNS VARCHAR(20000)
BEGIN
    DECLARE output VARCHAR(20000);

    SET output = REPLACE(SUBSTRING(SUBSTRING_INDEX($Str, $delim, $pos)
                 , LENGTH(SUBSTRING_INDEX($Str, $delim, $pos - 1)) + 1)
                 , $delim
                 , '');

    IF output = '' 
        THEN SET output = null;
    END IF;

    RETURN output;
END $$

You can iterate through the values like so

DROP PROCEDURE IF EXISTS GetNameValues $$
CREATE PROCEDURE GetNameValues()
BEGIN
    DECLARE i INTEGER;

    DROP TEMPORARY TABLE IF EXISTS TempList;
    CREATE TEMPORARY TABLE TempList(
        `Name` VARCHAR(256) COLLATE utf8_unicode_ci NOT NULL,
        `ValueList` VARCHAR(20000) COLLATE utf8_unicode_ci NOT NULL
    );
    DROP TEMPORARY TABLE IF EXISTS Result;
    CREATE TEMPORARY TABLE Result(
        `Name` VARCHAR(256) COLLATE utf8_unicode_ci NOT NULL,
        `Value` VARCHAR(128) COLLATE utf8_unicode_ci NOT NULL
    );

    INSERT INTO
        TempList
    SELECT
        I.`Name`,
        ExtractValue(Xml,'/Xml/Values/Value') AS ValueList
    FROM
        Item AS I
    WHERE
        I.TypeID = 'A'
    ;

    SET i = 1;
    REPEAT
        INSERT INTO
            Result
        SELECT
            `Name`,
            CAST(STRSPLIT(ValueList, ' ', i) AS CHAR(128)) AS Value
        FROM
            TempList
        WHERE 
            CAST(STRSPLIT(ValueList, ' ', i) AS CHAR(128)) IS NOT NULL
        ;

        SET i = i + 1;
        UNTIL ROW_COUNT() = 0
    END REPEAT;

    SELECT * FROM Result ORDER BY `Name`;
END $$

DELIMITER ;

CALL GetNameValues();

Hope this helps someone one day.