我在尝试从php中的预准备语句查询中获取行数时出现问题,我的查询如下所示:
$DBH = getDBH();
$stmt = $DBH->prepare("SELECT info FROM list WHERE tag = ?");
$stmt->bind_param("s",$tag);
$stmt->execute();
$stmt->bind_result($information);
我基本上只是想说如果没有结果返回显示“没有结果返回”有人可以帮忙吗?
答案 0 :(得分:3)
您需要先使用$statement->store_result()
。使用您的代码:
$DBH = getDBH();
$stmt = $DBH->prepare("SELECT info FROM list WHERE tag = ?");
$stmt->bind_param("s",$tag);
$stmt->execute();
$stmt->store_result();
$num_rows = $stmt->num_rows;
$stmt->bind_result($information);
答案 1 :(得分:1)
我不认识你正在使用的课程,但通常我会这样做:
$sql = "SELECT * FROM dummy WHERE category=13";
$result = mysql_query($sql);
if(mysql_num_rows($result)>0) {
// execute for positive results
} else {
// execute for 0 rows returned.
}
答案 2 :(得分:0)
$sql = "SELECT * FROM dummy WHERE category=13";
$result = mysqli_query($link, $sql);
$numrows=mysqli_num_rows($result)
if($numrows>0) {
// execute for positive results
} else {
// execute for 0 rows returned.
}