Re: how to use PHP variable in MYSQL query?

[Paul Ferrett]

Using backquotes in your query is like escaping a string.

If you have used reserved words (such as 'set', 'update' etc), or operators (such as -, + etc) as table/field names, MySQL will evaluate those as such.

I.e. if you were to write the query:

SELECT my-col FROM tbl_a

MySQL would assume you wanted to subtract the field `my` from the field `col`. Hence, `my-col` needs to be enclosed in backquotes.

SELECT mycol FROM tbl_a

would work perfectly fine in all versions of MySQL.