单个php页面上的多个SQL查询

Question

我有这段代码

 <?php
include("db.php");
$sql="select * from lead";
$result=mysqli_query($conn, $sql);
$i=0;
 ?>
 <?php while($row=mysqli_fetch_array($result)) { 
if($row['del']==1){ 
$sql1="select count(*) from notes where lead_id='$row[lead_id]'";
$var=mysqli_query($conn,$sql1);
                $var=mysqli_query($conn,$sql1);
                $var1=mysqli_num_rows($var);
?>

以下这个php代码是显示$ row获取的数据的表。问题是我没有得到正确的行数。它显示1但我有多行具有相同的潜在客户ID

Answer 1

您呼叫$sql1="select count(*) from notes where lead_id='$row[lead_id]'";
你已经$var=mysqli_query($conn,$sql1); $var1=mysqli_num_rows($var);
但是mysql_query只会返回一行count(*)。
因此，您必须执行$sql1="select * from notes where lead_id='$row[lead_id]'";
并致电mysqli_num_rows($var);

Answer 2

更改

$var=mysqli_query($conn,$sql1);

到

$var = mysqli_multi_query($conn, $sql1);