MySQL delete last 4 letters

MySQL delete last 4 letters

UPDATE mytable SET myfield =SUBSTRING(myfield, 1, LENGTH(myfield)-4) ;

If you want to also check whether the field ends with '.php'
before truncating, you can add this condition:
UPDATE mytable SET myfield = SUBSTRING(myfield, 1, LENGTH(myfield)-4)
WHERE RIGHT(myfield, 4) = '.php' ;

Oh, there's also LEFT()
which can be used instead of SUBSTRING()
as well

And CHAR_LENGTH()
should be used instead of LENGTH()
as it is multi-byte safe (while LENGTH()
is not):
UPDATE mytable SET myfield = LEFT(myfield, CHAR_LENGTH(myfield)-4)
WHERE RIGHT(myfield, 4) = '.php' ;