How can I add multiple constraints after the WHERE part of the UPDATE MySQL table statement? Is this possible? I have tried separating the constraints using commas. Thank you.
$update_error = mysqli_query($con, "UPDATE users SET error_level='3'
WHERE errors <= '650', errors > '200'");
You should add logical operator (https://dev.mysql.com/doc/refman/5.7/en/logical-operators.html) which will describe to MYSQL what is the connection between conditions:
It will look like this
mysqli_query($con, "UPDATE users SET error_level='3' WHERE errors <= '650' AND errors > '200'");
or this
mysqli_query($con, "UPDATE users SET error_level='3' WHERE errors <= '650' OR errors > '200'");
SQL :
WHERE errors <= '650'AND errors > '200'
You could also use BETWEEN ( I find this easier to read later )
WHERE errors BETWEEN 200 AND 650
UPDATE users SET error_level='3' WHERE errors <= '650' AND errors > '200'
AND...