mysql_affected_rows() returns the number of rows affected by the last query when doing an INSERT, UPDATE, or DELETE.

In MySQL 3.23, there is an exception when DELETE is used without a WHERE clause. In this case, the table is re-created as an empty table and mysql_affected_rows() returns zero for the number of records affected. In MySQL 4.0 and later, DELETE always returns the correct number of rows deleted. For a fast re-create, use TRUNCATE TABLE.

mysql_num_rows() returns the number of rows in a result set. With mysql_store_result(), mysql_num_rows() may be called as soon as mysql_store_result() returns. With mysql_use_result(), mysql_num_rows() may be called only after you have fetched all the rows with mysql_fetch_row().

mysql_insert_id() returns the ID generated by the last query that inserted a row into a table with an AUTO_INCREMENT index. See Section 17.6.3.35, “mysql_insert_id()”.

Some queries (LOAD DATA INFILE ..., INSERT INTO ... SELECT ..., UPDATE) return additional information. The result is returned by mysql_info(). See the description for mysql_info() for the format of the string that it returns. mysql_info() returns a NULL pointer if there is no additional information.