INSERT INTO，基于WHERE子句中的COUNT

Question

我根据供应商提供的产品类型将供应商记录插入到我的表中。

我正在做这样的事情;

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

不过，我只想补充一点，已经提供了至少一个“红色”项目的供应商。

“红”项没有特定的字段，“红”是产品栏中的一种类型。

如何用这种方式构造我的WHERE子句？

编辑

供应商（表）

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

RedItems（表）

ID / Name / NumItems 
1 / Smith /  23 

哪里NUMITEMS是从供应商的总（红色）项目。

Answer 1

如果数据是在同一个表，那么你可以做这样的事情：

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

如果没有，那么

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

我只是想添加已供应至少一个“红色”的供应商 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