Data read by pdo

The pdo query returns an object, and it is impossible to parse the query directly. . Only output line by line
$query = $conn->query($conn−>query(sql)->fetchALL() returns an array, the direct output is Array

$conn = new PDO("mysql:host=$dbhost;dbname=$dbname;charset=$charset", $dbuser, $dbpass);
 $sql = "SELECT * FROM $tbname";
 if ( $query = $conn->query($sql) )
 {
     echo "<p>Number Name Start Time End Time</p>";
     foreach ($query as $row)
     {
         echo $row['activity_no'] .'      ' ;
         echo $row['activity_name'] .'      ' ;
         echo $row['activity_begin_time'] .'      ' ;
         echo $row['activity_end_time'] .'      ' ;
         echo $row['activity_location'] ;
         echo $row['activity_content'] . "<br>";
     }
   }
 Number Name Start time End time

 1 Thunderstorm 2020-06-12 20:59:56 2020-06-15 20:59:58
 2 Brainstorm 2020-06-12 21:01:04 2020-06-13 21:01:05
 3 points
 4 Poetry recitation
 6 The most dazzling national style Arctic dance

Convert json

I don't know why I think of this format, the front end likes this wow. . . .

if ( $query = $conn->query($sql) )
{
   $result = json_encode($query->fetchAll());
   echo $result;
}
[{"activity_no":"1","0":"1","activity_name":"\u96f7\u96e8","1":"\u96f7\u96e8","activity_begin_time":"2020-06-12 20:59:56","2":"2020-06-12 20:59:56","activity_end_time":"2020-06-15 20:59:58","3":"2020-06-15 20:59:58","activity_location":null,"4":null,"activity_content":null,"5":null},{"activity_no":"2","0":"2","activity_name":"\u5934\u8111\u98ce\u66b4","1":"\u5934\u8111\u98ce\u66b4","activity_begin_time":"2020-06-12 21:01:04","2":"2020-06-12 21:01:04","activity_end_time":"2020-06-13 21:01:05","3":"2020-06-13 21:01:05","activity_location":null,"4":null,"activity_content":null,"5":null},{"activity_no":"3","0":"3","activity_name":"\u7455\u79ef\u5206","1":"\u7455\u79ef\u5206","activity_begin_time":null,"2":null,"activity_end_time":null,"3":null,"activity_location":null,"4":null,"activity_content":null,"5":null},{"activity_no":"4","0":"4","activity_name":"\u8bd7\u6b4c\u6717\u8bf5","1":"\u8bd7\u6b4c\u6717\u8bf5","activity_begin_time":null,"2":null,"activity_end_time":null,"3":null,"activity_location":null,"4":null,"activity_content":null,"5":null},{"activity_no":"6","0":"6","activity_name":"\u6700\u70ab\u6c11\u65cf\u98ce","1":"\u6700\u70ab\u6c11\u65cf\u98ce","activity_begin_time":null,"2":null,"activity_end_time":null,"3":null,"activity_location":"\u5317\u6781","4":"\u5317\u6781","activity_content":"\u5c2c\u821e","5":"\u5c2c\u821e"}]

But a closer look not only outputs the default key-value pairs, but also the default number subscript-value pairs. Emm must remove one of them. Wow, here remove the latter

if ( $query = $conn->query($sql) )
{
   $result = json_encode($query->fetchAll(PDO::FETCH_ASSOC));
   echo $result;
}
[{"activity_no":"1","activity_name":"\u96f7\u96e8","activity_begin_time":"2020-06-12 20:59:56","activity_end_time":"2020-06-15 20:59:58","activity_location":null,"activity_content":null},{"activity_no":"2","activity_name":"\u5934\u8111\u98ce\u66b4","activity_begin_time":"2020-06-12 21:01:04","activity_end_time":"2020-06-13 21:01:05","activity_location":null,"activity_content":null},{"activity_no":"3","activity_name":"\u7455\u79ef\u5206","activity_begin_time":null,"activity_end_time":null,"activity_location":null,"activity_content":null},{"activity_no":"4","activity_name":"\u8bd7\u6b4c\u6717\u8bf5","activity_begin_time":null,"activity_end_time":null,"activity_location":null,"activity_content":null},{"activity_no":"6","activity_name":"\u6700\u70ab\u6c11\u65cf\u98ce","activity_begin_time":null,"activity_end_time":null,"activity_location":"\u5317\u6781","activity_content":"\u5c2c\u821e"}]

reference

• https://blog.csdn.net/weixin_30469895/article/details/95589933