在 html 中显示表数

试试这个代码

<?php
$con = new mysqli("localhost","root","","test");

// Check connection
if ($con -> connect_errno) {
  echo "Failed to connect to MySQL: " . $con -> connect_error;
  exit();
}
$data = array();
$date_list= array();
$sql_date_list ="SELECT start_datetime from appointment GROUP BY start_datetime";
$result_date_list = mysqli_query($con, $sql_date_list); 
$sql_loc_list = "SELECT `name` FROM `location` GROUP BY `name`";
$result_loc_list = mysqli_query($con, $sql_loc_list); 
$k=0;
while ($row =mysqli_fetch_assoc($result_loc_list)){
    $data +=[$row['name']=>array()];
    if($k==0){
        while($row2 =mysqli_fetch_assoc($result_date_list)){
            array_push($date_list,$row2['start_datetime']);
            $data[$row['name']]+=[$row2['start_datetime']=>0];
        }
        $k++;
    }else{
        foreach($date_list as $date){
            $data[$row['name']]+=[$date=>0];
        }
    }
}

$sql_getdata = "SELECT t2.name as loc_name, t1.start_datetime, COUNT(t1.location_id) AS count FROM appointment t1 JOIN location t2 ON t1.location_id = t2.id GROUP BY t1.location_id,t1.start_datetime"; 
$result = mysqli_query($con, $sql_getdata); 
while($row =mysqli_fetch_assoc($result)){
    $data[$row['loc_name']][$row['start_datetime']]=$row['count'];
}
$table="<table border='1'>";
$table.="<tr>";
$table.="<th>location</th>";
foreach ($date_list as $date) {
    $table.="<th>".$date."</th>";
}
$table.="</tr>";
foreach ($data as $key=>$date) {
    $table.="<tr>";
    $table.="<td>".$key."</td>";
        foreach($date as $key2=>$count){
            $table.="<td>".$count."</td>";
        }
    $table.="</tr>";
}

$table.="<table>";
echo $table;
?>

输出