RETURN TRIM(SUBSTRING_INDEX(SUBSTRING_INDEX(Source, Delimiter, Number), Delimiter, -1));

ERROR 1046 (3D000): No database selected

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'CREATE FUNCTION SUBSTRING_BY_INDEX(Source VARCHAR(255), Delimiter VARCHAR(255), ' at line 2

mysql> DELIMITER //
mysql> CREATE FUNCTION SUBSTRING_BY_INDEX(Source VARCHAR(255), Delimiter VARCHAR(255), Number INT)
    -> CREATE FUNCTION SUBSTRING_BY_INDEX(Source VARCHAR(255), Delimiter VARCHAR(255), Number INT)
    -> RETURNS VARCHAR(255)
    -> DETERMINISTIC
    -> NO SQL
    -> BEGIN
    -> IF ((LENGTH(Source) - LENGTH(REPLACE(Source, Delimiter, ''))) / LENGTH(Delimiter) >= Number - 1) AND (Number > 0)
    -> THEN
    ->
Display all 2814 possibilities? (y or n)
    ->  TRIM(SUBSTRING_INDEX(SUBSTRING_INDEX(Source, Delimiter, Number), Delimiter, -1));
    -> ELSE
    ->
Display all 2814 possibilities? (y or n)
    ->  '';
    ->
Display all 2814 possibilities? (y or n)
    ->  '';
    -> RETURN '';
    -> END IF;
    -> END;
    -> //

SELECT product_id, attribute_id, language_id, attr_pos, SUBSTRING_BY_INDEX(text, 'x', attr_pos) attr
FROM oc_product_attribute, (SELECT 1 attr_pos UNION SELECT 2 UNION SELECT 3) dummy