Heim >Backend-Entwicklung >PHP-Tutorial >thinkphp count用于group就无法获取数量
<code> $count = $order->where($con) ->join("LEFT JOIN x_goods ON x_goods.goods_id = x_order.order_goodsid") ->order("order_createtime desc") ->group("order_no") ->count();// 查询满足要求的总记录数</code>
无法获取数量
<code> $count = $order->where($con) ->join("LEFT JOIN x_goods ON x_goods.goods_id = x_order.order_goodsid") ->order("order_createtime desc") ->group("order_no") ->select();// 查询满足要求的总记录数</code>
可以获取数据
<code> $count = $order->where($con) ->join("LEFT JOIN x_goods ON x_goods.goods_id = x_order.order_goodsid") ->order("order_createtime desc") ->group("order_no") ->count();// 查询满足要求的总记录数</code>
无法获取数量
<code> $count = $order->where($con) ->join("LEFT JOIN x_goods ON x_goods.goods_id = x_order.order_goodsid") ->order("order_createtime desc") ->group("order_no") ->select();// 查询满足要求的总记录数</code>
可以获取数据
那就直接写成
$count = count($order->where($con) ->join("LEFT JOIN x_goods ON x_goods.goods_id = x_order.order_goodsid") ->order("order_createtime desc") ->group("order_no") ->select());// 查询满足要求的总记录数
缺陷是大数据量下会影响效率,导致网络io和资源消耗过大。小业务的话就不必多虑。
我瞎猜的哈,你试试
<code class="php">$count = $order->where($con) ->join("LEFT JOIN x_goods ON x_goods.goods_id = x_order.order_goodsid") ->order("order_createtime desc") ->group("order_no") ->field("count(*)") ->select();//</code>
最好把执行的SQL打印出来看下,比较复杂的逻辑用原生SQL最好,没必要拘泥。