PHP-mysql_num_rows（）期望參數1成爲資源

Question

$query = "SELECT * FROM XXXX"; 
$result = mysql_query($query); 
$noOfRows = mysql_num_rows($result); 

如何檢查$result在得到mysql_num_rows的結果之前是否爲空？

Answer 1

您可以用三元操作符檢查$result並設置$noOfRows到0如果是false：

$query = "SELECT * FROM XXXX"; 
$result = mysql_query($query); 
$noOfRows = (false===$result)? 0 : mysql_num_rows($result);