如果您有 MySQL 8.0,则只能使用正则表达式。
但是,如果您的链接位于单独的字段中,则可以创建并使用 SP 来清理它们:
DELIMITER $$
CREATE FUNCTION CLEANUP(
aString VARCHAR(255)
, aName VARCHAR(15)
)
RETURNS VARCHAR(255)
BEGIN
SET @u = SUBSTRING_INDEX(aString, '?', 1);
SET @q = SUBSTRING_INDEX(aString, '?', -1);
IF @q = aString THEN
RETURN aString; -- no '?' char found
ELSE
SET @f = LOCATE(CONCAT(aName, '='), @q);
SET @query = IF(@f > 1, SUBSTR(@q, 1, @f - 1), '');
IF @f > 0 THEN
SET @t = LOCATE('&', @q, @f + LENGTH(aName) + 1);
IF @t > 0 THEN
SET @query = CONCAT(@query, SUBSTR(@q, @t + 1));
END IF;
END IF;
IF @query = '' THEN
RETURN @u;
ELSE
RETURN CONCAT(@u, '?', TRIM('&' FROM @query));
END IF;
END IF;
END
$$
DELIMITER ;
然后:
SELECT
CLEANUP('https://example.com/public/images/someimage.jpg?itok=WDGFySy&b=2', 'itok')
, CLEANUP('https://example.com/public/images/someimage.jpg?itok=WDGFySy', 'itok')
, CLEANUP('https://example.com/public/images/someimage.jpg?a=1&itok=WDGFySy', 'itok')
, CLEANUP('https://example.com/public/images/someimage.jpg?a=1&itok=WDGFySy&b=2', 'itok')
;