Mysql_fetch_array () expectsparameter1toberesource, booleangiveninD: What is the solution? Solution

Mysql_fetch_array () expectsparameter1toberesource, booleangiveninD: What is the solution? Mysql_fetch_array () expectsparameter1toberes mysql_fetch_array () expects parameter 1 to be resource, boolean given in D: What is the solution?
Mysql_fetch_array () expects parameter 1 to be resource, boolean given in D: \ xampp \ htdocs \ 4.php on line 12

What is the error? How to correct it? Thank you ~

The code is as follows:

$ Con = mysql_connect ("localhost", "root ","");
// Establish a connection through the server locahost. the user name is root and no password is required.

If (! $ Con)
{
Die ('could not connect: '. mysql_error ());
} // If it fails, an error is displayed.
Mysql_select_db ("crms", $ con); // select a database
$ Result = mysql_query ("SELECT * FROM Cno"); // query

While ($ row = mysql_fetch_array ($ result) // Print
{
Echo $ row ['cno']. "". $ row ['cno'];
Echo"
";
}

Mysql_close ($ con );
?>

------ Solution --------------------
Discussion

Access denied for user ''@ 'localhost' to database 'crms'

How can I change this error?