mysql_query返回值

Question

The mysql_query function in php returns TRUE on success and FALSE on failure.

My question is what is considered success ?

In other words, what is returned when there is nothing from a SELECT statement, or if there is an UPDATE and nothing that matches the WHERE clause. Does it return FALSE or something like an empty resource ?

I'm trying to differentiate between a db error, and an empty result.

Answer 1

Success means "no errors". Getting zero rows is not an error.

Edit: Just checked the manual page and the explanation is pretty clear (not sure where you got yours):

For SELECT, SHOW, DESCRIBE, EXPLAIN and other statements returning resultset, mysql_query() returns a resource on success, or FALSE on error .

For other type of SQL statements, INSERT, UPDATE, DELETE, DROP, etc, mysql_query() returns TRUE on success or FALSE on error .

Answer 2

TRUE means no errors.

If you want to know the number of rows in the resultset use: mysql_num_rows($result) .

If it is an update and you want to know if rows have changed use: mysql_affected_rows($result) .