How to use mysql_num_rows??

[Anon]

can anyone teach me how to use the function mysql_num_rows??

here is my code:
$result=mysql_query("select * from mytable");
$rows=mysql_num_rows($result);

then the following error occur in the second line:
Supplied argument is not a valid MySQL result resource

Would somebody help me pls!!

[Anon]

you have forgot the connection parameter in the mysql_query function, should be something like this..

$mysql_link = mysql_connect("localhost", "username", "password");
mysql_select_db("dbname", $mysql_link);

then:

$result = mysql_query("SELECT * FROM mytable", $mysql_link);
$rows = mysql_num_rows($result);

that should do it..

[Anon]

I have already used the function mysql_connect() and mysql_select_db() to connect and select the database

but error still occur
pls help

[Anon]

I think you are missing the link Identifier ie $db from your query statement

$db = mysql_connect("host", "user", "pass");
mysql_select_db(dbname, $db)
$result=mysql_query("select * from mytable", $db);
$rows=mysql_num_rows($result);

[Anon]

you don't have to supply a link id to mysql_query... more likely is that the query is causing an error and so a the result id is invalid (eg. if no table with that name exist)

print out mysql_error() to have a look

dom