PHP json_encode和SQL服务器回调函数只返回一个结果

Question

I'm trying to set up a PHP callback function for use in our application. It needs to pull data from a SQL server, and while I can get it to work initially, it's not quite doing what I want.

Code:

//Callback function for passing queries

function queryCallback($conn, $query) {
  $response = sqlsrv_query($conn, $query);

  while ($row = sqlsrv_fetch_array($response)){
    if ($row === false) {
       die(print_r(sqlsrv_errors(), true));
    }
    $responseData[] = $row;
  }
  foreach($responseData as $v) {
    $output[key($v)] = current($v);
  }
  $responseDataJSON = JSON_encode($output, 128);
  return $responseDataJSON;
}

In the above, $conn represents our server creds, as passed to sqlsrv_connect(), and $query is the string containing the query passed to SQL. Both have been verified as working.

Issue:

This code contacts the server correctly, and runs the query, but it only returns one result. This is obviously a problem with how the loops are set up, but I just can't spot it

Answer 1

My feeling is that the following $row = sqlsrv_fetch_array($response) is fetching the whole row as an array, but your usage of $output[key($v)] = current($v) is only returning the first column with the same key, and overwriting the $output index with every iteration.

foreach($responseData as $v) {
  $output[key($v)] = current($v);
}

lets say you instead perform

foreach($responseData as $k => $v) {
  $output[$k] = $v;
}

At which point this is redundant as $responseData[] already is this structure.

You may actually want this if you plan to extract just the first column out of your row.

foreach($responseData as $v) {
  $output[] = current($v);
}