MySQL联合与MySQL内部连接结合

Question

我想从allinventory_tb得到描述和模型。

所以我做了内部连接，但是当我要显示描述和模型的时候。

错误是：

注意:未定义索引:描述，注意:未定义索引:模型。

有什么建议吗？

  |allinventory_tb|
  ----------------
  |in_code        |
  |description    |
  |model          |
  ---------------
    $sql = "select t.itemcode  as itemcode ,sum(t.qty) as qty
    from ( 
    select itemcode,qty  from barcode INNER JOIN allinventory_tb on barcode.itemcode = allinventory_tb.in_code
    union all
    select itemcode,qty from adjustment_tb INNER JOIN allinventory_tb on adjustment_tb.itemcode = allinventory_tb.in_code where adjustment_tb.status='APPROVED'
    union all
    select itemcode,(qty * -1) from soldout_pd INNER JOIN allinventory_tb on soldout_pd.itemcode = allinventory_tb.in_code) as t
    group by itemcode";

    $result = $conn->query($sql);

Answer 1

和您的查询，即

$sql = "select t.itemcode  as itemcode ,sum(t.qty) as qty
    from ( 
    select itemcode,qty  from barcode INNER JOIN allinventory_tb on barcode.itemcode = allinventory_tb.in_code
    union all
    select itemcode,qty from adjustment_tb INNER JOIN allinventory_tb on adjustment_tb.itemcode = allinventory_tb.in_code where adjustment_tb.status='APPROVED'
    union all
    select itemcode,(qty * -1) from soldout_pd INNER JOIN allinventory_tb on soldout_pd.itemcode = allinventory_tb.in_code) as t
    group by itemcode";


    $result = $conn->query($sql);

您将无法访问description和model列值，因为您没有在查询中指定Re欲列名，所以当您尝试在PHP中访问查询结果时，您将得到如下通知错误：

注意:未定义索引:描述，注意:未定义索引:模型。

尝试这个查询

$sql = "select description,model,t.itemcode  as itemcode ,sum(t.qty) as qty
    from ( 
    select description,model,itemcode,qty  from barcode as bc INNER JOIN allinventory_tb as ait on bc.itemcode = ait.in_code
    union all
    select description,model,itemcode,qty from adjustment_tb as adt INNER JOIN allinventory_tb as ait1 on adt.itemcode = ait1.in_code where adjustment_tb.status='APPROVED'
    union all
    select description,model,itemcode,(qty * -1) from soldout_pd as slp INNER JOIN allinventory_tb as ait2 on slp.itemcode = ait2.in_code) as t
    group by itemcode";


$result = $conn->query($sql);

希望这对你有用..。