INSERT INTO，基於WHERE子句中的COUNT

Question

我根據供應商提供的產品類型將供應商記錄插入到我的表中。

我正在做這樣的事情;

INSERT INTO RedItems (ID, Name, NumItems) 
SELECT ID, Name, NULL 
FROM supplier 
WHERE status = 'Supplier' 

不過，我只想補充一點，已經提供了至少一個「紅色」項目的供應商。

「紅」項沒有特定的字段，「紅」是產品欄中的一種類型。

如何用這種方式構造我的WHERE子句？

編輯

供應商（表）

ID / Name / Status / Product 
1 / Smith / Supplier / Red 
2 / Baxter / Supplier / Round 

RedItems（表）

ID / Name / NumItems 
1 / Smith /  23 

哪裏NUMITEMS是從供應商的總（紅色）項目。

Answer 1

如果數據是在同一個表，那麼你可以做這樣的事情：

INSERT INTO RedItems (ID, Name, NumItems) 
SELECT ID, Name, count(product) 
FROM mytable 
WHERE status = 'Supplier' 
    AND product = 'red' 
GROUP BY ID, Name 

如果沒有，那麼

INSERT INTO RedItems (ID, Name, NumItems) 
SELECT t1.ID, t1.Name, count(p.product) 
FROM mytable t1 
INNER JOIN products p 
    ON t1.id = p.supplierID 
WHERE t1.status = 'Supplier' 
    and p.product = 'red' 
GROUP BY t1.ID, t1.Name 

Answer 2

INSERT INTO RedItems (ID, Name, NumItems) 
SELECT suppliers.ID, suppliers.Name, count(distinct products.id) 
FROM suppliers 
    inner join products on suppliers.id = products.supplierid 
WHERE status = 'Supplier' and products.type='red' 
group by suppliers.ID, suppliers.Name 

Answer 3

我只是想添加已供應至少一個「紅色」的供應商 商品

INSERT INTO RedItems (ID, Name, NumItems) 
SELECT ID, Name, COUNT(Product) 
FROM supplier 
WHERE status = 'Supplier' 
    AND Product = 'RED' 
GROUP BY ID, Name 
HAVING COUNT(Product) >= 1