MySQL Substring Grab all but last three characters

Basically, I am trying to find 开发者_运维百科the inverse of this command: substring(term, -3).

Try this:

SELECT SubStr(myColumn, 1, LENGTH(myColumn) - 3)
FROM MyTable

or

SELECT LEFT(myColumn, LENGTH(myColumn) - 3)
FROM MyTable

This should do it: SELECT SUBSTRING(term FROM 1 FOR LENGTH(term)-3)

If you need it to match in a where comparison you could use

WHERE somefield LIKE 'term___'