Hier is het:
DELIMITER $$
DROP FUNCTION IF EXISTS `replace_ci`$$
CREATE FUNCTION `replace_ci` ( str TEXT,needle CHAR(255),str_rep CHAR(255))
RETURNS TEXT
DETERMINISTIC
BEGIN
DECLARE return_str TEXT DEFAULT '';
DECLARE lower_str TEXT;
DECLARE lower_needle TEXT;
DECLARE pos INT DEFAULT 1;
DECLARE old_pos INT DEFAULT 1;
SELECT lower(str) INTO lower_str;
SELECT lower(needle) INTO lower_needle;
SELECT locate(lower_needle, lower_str, pos) INTO pos;
WHILE pos > 0 DO
SELECT concat(return_str, substr(str, old_pos, pos-old_pos), str_rep) INTO return_str;
SELECT pos + char_length(needle) INTO pos;
SELECT pos INTO old_pos;
SELECT locate(lower_needle, lower_str, pos) INTO pos;
END WHILE;
SELECT concat(return_str, substr(str, old_pos, char_length(str))) INTO return_str;
RETURN return_str;
END$$
DELIMITER ;
Gebruik:
$sql = "
UPDATE timeline
SET message = replace_ci(message,'".$targetuserold."', '".$targetusernew."')
";