このように記録された場合、0未満の値を取る方法は？

Question

マイクエリ：

select c.location_id as id_gudang, c.location_name as nama_gudang, a.item_code as id_barang, a.item_name as nama_barang, sum(b.item_qty) as qty 
    from t_inventory as a 
    join t_inventory_transaction as b on a.item_id = b.item_id 
    join t_site_location as c on b.whse_id = c.location_id 
    group by a.item_code 

クエリから、このデータを、その後、あなたはあなたがnull値（そのテーブルに存在しないものを）したいqty < 0をしたいと言ったときに仮定し

Answer 1

、あなたのようなサブクエリにあなたのSQLをラップすることができます使用

select * 
from (
    select c.location_id as id_gudang, c.location_name as nama_gudang, a.item_code as id_barang, a.item_name as nama_barang, sum(b.item_qty) as qty 
    from t_inventory as a 
    join t_inventory_transaction as b on a.item_id = b.item_id 
    join t_site_location as c on b.whse_id = c.location_id 
    group by a.item_code) t 
where qty < 0 

それともHAVING：

select c.location_id as id_gudang, c.location_name as nama_gudang, a.item_code as id_barang, a.item_name as nama_barang, sum(b.item_qty) as qty 
from t_inventory as a 
join t_inventory_transaction as b on a.item_id = b.item_id 
join t_site_location as c on b.whse_id = c.location_id 
group by a.item_code 
having qty < 0 

Answer 2

あなたは代わりにouter joinを使用する必要があります：

select c.location_id as id_gudang, c.location_name as nama_gudang, 
     a.item_code as id_barang, a.item_name as nama_barang, 
     sum(b.item_qty) as qty 
from t_inventory as a 
    left join t_inventory_transaction as b on a.item_id = b.item_id 
    left join t_site_location as c on b.whse_id = c.location_id 
group by a.item_code 

• A Visual Explanation of SQL Joins

彼らは他のテーブルに存在しない場合、これは関係なく、t_inventoryテーブルからすべてのレコードを返します。あなたがそれをしたい場合