php - 使用 SUM 的 ZF2 自定义数据库查询

Question

有人可以提示我做错了什么吗？

public function getPaymentSumByTypeAndProject($project_id,$type) {
  $type = (int) $type;
  $project_id = (int) $project_id;
  $rowset = $this->tableGateway->select(array('total_amount' => new Expression('SUM(payment.amount)')))->where(array('type' => $type, 'project_id' => $project_id));
  $row = $rowset->toArray();
  if (!$row) {
    throw new \Exception("Busted :/");
  }
  return $rowset;
}

我想做同样的查询:

SELECT SUM(amount) FROM payment WHERE type='$type' AND project_id ='$project_id';

编辑: 我取得了很小的进步，我已经想出了如何对整个专栏求和

public function getPaymentSumByTypeAndProject($project_id, $type) {
    $type = (int) $type;
    $project_id = (int) $project_id;
    $resultSet = $this->tableGateway->select(function (Select $select) {
                $select->columns(array(new \Zend\Db\Sql\Expression('SUM(amount) as amount')))->where('type="0"');
            });
    return $resultSet;

也许有人可以帮我弄清楚如何添加条件:“WHERE type='$type' AND project_id='$project_id'”？

Answer 1

我知道这是一个老问题，但我遇到了它并想我会投入我的两分钱:

public function getPaymentSumByTypeAndProject($project_id, $type) {
    // This TableGateway is already setup for the table 'payment'
    // So we can skip the ->from('payment')
    $sql = $this->tableGateway->getSql();

    // We'll follow the regular order of SQL ( SELECT, FROM, WHERE )
    // So the query is easier to understand
    $select = $sql->select()
            // Use an alias as key in the columns array instead of
            // in the expression itself
            ->columns(array('amount' => new \Zend\Db\Sql\Expression('SUM(amount)')))
            // Type casting the variables as integer can take place
            // here ( it even tells us a little about the table structure )
            ->where(array('type' => (int)$type, 'project_id' => (int)$project_id));

    // Use selectWith as a shortcut to get a resultSet for the above select
    return $this->tableGateway->selectWith($select);
}

此外，可以像这样从表网关中检索适配器:

$adapter = $this->tableGateway->getAdapter();

但是当您选择使用上述方法时，您实际上不再需要它了。