Returns a positive MySQL result resource to the query
result, or FALSE on error.
The function also returns
TRUE/FALSE for INSERT/UPDATE/DELETE queries
to indicate success/failure.
mysql_db_query() selects a
database and executes a query on it. If the optional link
identifier isn't specified, the function will try to find an
open link to the MySQL server and if no such link is found
it'll try to create one as if
mysql_connect() was called with no arguments.
Be aware that this function does NOT switch back to the database
you were connected before. In other words, you can't use this
function to
temporarily run a sql query on another database,
you would have to manually switch back. Users are strongly
encouraged to use the database.table
syntax in their sql queries instead of this function.
See also mysql_connect() and
mysql_query().
注: This function has been deprecated since PHP 4.0.6. Do not use this function. Use mysql_select_db() and mysql_query() instead.