Question

第3天......

这是代码，然后我将解释任务：

$outerquery = "SELECT TOP 1 D2001_SPID, D3001_MeterId as MeterID, D3009_MeterReadDate, D3008_MeterRead, D3010_MeterReadType, customer_id, reading_by FROM rc_meter_reads WHERE (D3001_MeterId IN (SELECT water_meter_id FROM rc_meters WHERE (status = '1'))) OR (D3001_MeterId IN (SELECT waste_meter_id FROM rc_meters AS rc_meters_1 WHERE (status = '1'))) AND (D3010_MeterReadType = 'C') ORDER BY D3009_MeterReadDate DESC";
$rs6 = sqlsrv_query($conn,$outerquery);
while($outerrow = sqlsrv_fetch_array($rs6)) {
  $meterID = $outerrow['MeterID'];
  $query7 = "SELECT TOP 1 * from rc_meter_reads where D3001_MeterId = '" . $meterID . "'";// (SELECT MAX(D3009_MeterReadDate) from rc_meter_reads) ORDER BY D3009_MeterReadDate DESC";
  $rs7 = sqlsrv_query($conn1,$query7);
  while($row = sqlsrv_fetch_array($rs7))
  {
    if(strtotime($nextreaddue) >= strtotime($today)) {
      //$data.= $row['customer_id'] . "," . $row['D2001_SPID'] . "," . $row['D3001_MeterId'] . "," . $row['D3008_MeterRead'] . "," . $meterreaddate . "," . $lastreadadd196 . "</br>\n";
    }
  }

问题是，我需要运行外部查询，专门缩小结果，然后在其中运行第二个查询，我想我可能会发生错误，但是当我一直在查看它时几天现在想知道发生了什么，我需要外面的帮助，并转介到庇护。这里实际发生的是外部查询运行，然后内部查询不使用外部查询中的数据在窄数据上运行。因为它应该只有1个结果，是最近的...我不知道这是否是最好的方式来做到这一点，我也看着将它存储到一个数组，但它再次没有像预期的那样做，所有的想法都欢迎这一点。

注意：我大约两周前才开始使用MSSQL，所以给我一点功劳;）

非常感谢任何和所有帮助！

Answer 1

你从第一个查询中选择了一行，你似乎从secondo查询中选择了同一行具有相同的$ meterdID 这意味着您可以在第一个查询中检索所需的所有信息（最终添加缺少的列是select）那么你可以简单地选择并构建你没有while循环的数据，但只是检查你是否有结果，例如：

  $outerquery = "SELECT TOP 1 
          D2001_SPID
        , D3001_MeterId as MeterID
        , D3009_MeterReadDate
        , D3008_MeterRead
        , D3010_MeterReadType
        , customer_id
        , reading_by 
      FROM rc_meter_reads 
      WHERE (D3001_MeterId IN (
          SELECT water_meter_id 
          FROM rc_meters WHERE (status = '1')
      )) 
      OR (D3001_MeterId IN (
          SELECT waste_meter_id 
          FROM rc_meters AS rc_meters_1 WHERE (status = '1')
      )) 
      AND (D3010_MeterReadType = 'C') 
      ORDER BY D3009_MeterReadDate DESC";

  if ($row = sqlsrv_fetch_array($rs6)){
      $data.= $row['customer_id'] .  "," . 
          $row['D2001_SPID'] . "," . 
          $row['D3001_MeterId'] . "," . 
          $row['D3008_MeterRead'] . "," . 
          $meterreaddate . "," . 
          $lastreadadd196 . "</br>\n";
  }

查询

1 个答案: