18.1 Data Types

The following PHP data types are specialized types for database access:

cresource

A connection resource handle. An integer returned from the functions mysql_connect( ), and mysql_pconnect( ). Both functions are used to establish a connection to a MySQL DBMS, and are described later in this chapter. The connection resource handle is used as a parameter to several functions (such as mysql_select_db( ), mysql_query( ), and mysql_affected_rows( )) to determine or change aspects of the connection.

qresource

A query resource handle. An integer returned from functions such as mysql_query(), mysql_list_fields(), mysql_list_dbs(), and mysql_unbuffered_query(). These functions are used to execute a query through a connection resource handle, and are described later in this chapter. A query resource handle is used as a parameter to several functions (such as mysql_fetch_array(), mysql_tablename(), and mysql_num_rows()) to retrieve a query's output or information about the query.