合并两个 SELECT 语句并返回一个 JSON 响应

Question

I would like to merge the results of two select statements and return one single JSON response. Basically, I want to return id, name, company, and email for every record found, but also return the signature column if the ticket matches the POST data.

Also, is it possible to remove any duplicate records in the final array?

$selectTable = "tickets_info";
$selectColumns = "id, name, company, email";

$stmt = $conn->prepare("SELECT $selectColumns FROM $selectTable WHERE created BETWEEN DATE_SUB(NOW(), INTERVAL 30 DAY) AND NOW() ORDER BY id DESC");
$stmt->execute();

if (isset($_POST['ticket'])) {

    $stmt2 = $conn->prepare("SELECT signature FROM tickets_info WHERE ticket = ?");
    $stmt2->execute(array($_POST['ticket']));

}

$results = $stmt->fetchAll();

if (isset($_POST['ticket'])) {

    $results = $stmt2->fetchAll();

}

if ($results) {

    header("Content-Type: application/json"); 
    echo json_encode($results);

}

Answer 1

I would loop through the query response with something along these lines:

$stmt = $conn->prepare("SELECT id, name, company, email, signature, ticket FROM tickets_info WHERE created BETWEEN DATE_SUB(NOW(), INTERVAL 30 DAY) AND NOW() ORDER BY id DESC");
$stmt->execute() ;
$rows = $stmt->fetchAll(PDO::FETCH_ASSOC);

foreach ($rows as $row) {
  $response[$i]['id'] = $row['id'] ;
  $response[$i]['name'] = $row['name'] ;
  $response[$i]['company'] = $row['company'] ;
  $response[$i]['email'] = $row['email'] ;

  if ($row['ticket'] == $_POST['ticket']) $response[$i]['signature'] = $row['signature'] ;
  else $response[$i]['signature'] = NULL ;

  $i++ ;
}

header("Content-Type: application/json"); 
echo json_encode($response);

You only do one SQL query and loop through the response once. If that row matches the AJAX ticket query, we add the signature to the array of objects. If not, we set the signature value to null .

Answer 2

The right way to do is use Join . If you don't want to do it with join you can first put the results in two different arrays. then merge those two seperate arrays and then filter any duplicate arrays.

Remember you want to have the same keys for both Sql Queries.