MySQL聯盟全部結合MySQL內部聯接

Question

我想從allinventory_tb獲取描述和模型。

所以我做了內部連接，但是當我要顯示描述和模型時。

的錯誤是這樣的：

說明：未定義指數：說明，注意：未定義指數：模型。

有什麼建議嗎？

|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

有了您的查詢即

$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); 

您將無法訪問的描述和型號的列值，因爲你沒有在查詢中指定的願望列名，所以當您嘗試訪問查詢結果在PHP中，您將收到Notice Notice錯誤，例如：

注意：未定義索引：說明，注意：未定義索引：model。

嘗試此查詢

$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); 

希望這對你的作品...