问SQL返回错误的行数。

EN

<?php
$servername = "localhost";
$username = "root";
$password = "root";
$dbName = "database";

$var1 = 't1c';
$var2 = 't1c';
$var3 = 't1c';
$var4 = 't1c';
$var5 = 't2c';
$var6 = 't2c';
$var7 = 't2c';
$var8 = 't2c';

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
error_reporting(E_ALL);
ini_set('display_errors', 1);


$conn = new mysqli ($servername, $username, $password, $dbName);

if(!$conn){
    die("Connection failed. ". mysqli_connect_error());
}

$sql = "SELECT ";
$sql .= "(SELECT COUNT(*) FROM table1) AS $var1, ";
$sql .= "(SELECT COUNT(*) FROM table2) AS $var2, ";
$sql .= "(SELECT COUNT(*) FROM table3) AS $var3, ";
$sql .= "(SELECT COUNT(*) FROM table4) AS $var4, ";
$sql .= "(SELECT COUNT(*) FROM table5) AS $var5, ";
$sql .= "(SELECT COUNT(*) FROM table6) AS $var6, ";
$sql .= "(SELECT COUNT(*) FROM table7) AS $var7, ";
$sql .= "(SELECT COUNT(*) FROM table8) AS $var8; ";

$result = mysqli_query($conn ,$sql);

if(mysqli_num_rows($result) > 0) {

    while($row = mysqli_fetch_assoc($result)){

        echo "var1:" . $row[$var1] . "|var2:" . $row[$var2] . "|var3:" . 
$row[$var3] . "|var4:" . $row[$var4] . "|var5:". $row[$var5] . "|var6:". 
$row[$var6] . "|var7:". $row[$var7] . "|var8:". $row[$var8] . ";";

    }
}
?>