PHP appears Warning:mysql_fetch_array (): supplied argument is not a valid MySQL result solution

PHP appears Warning:mysql_fetch_array (): supplied argument is not a valid MySQL result
$link = mysql_connect ("localhost", "root", "root") or Die ("Database connection Failed". Mysql_error ());
mysql_select_db ("Student", $link);
mysql_query ("Set names gb2312");
?>
$sql =mysql_query ("SELECT * Ftom tb_student");
$info =mysql_fetch_array ("$sql");
if ($_post[submit]== "query")
{
$tex _book=$_post[tex_book];
$sql =mysql_query ("select * Ftom tb_student where sno like '% '. Trim ($tex _book)." %'");
$info =mysql_fetch_array ($sql);

}
?>

------Solution--------------------
$info =mysql_fetch_array ("$sql");
=
$info =mysql_fetch_array ($sql);

Do not add quotation marks here.


Also make sure that the SELECT * ftom tb_student SQL is executed successfully.

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