将数据从一列插入/更新到另一列，并进行冲突更新，只有那些特定字段具有不同值的列吗？

Question

我有两列products/tmp_products，其规格如下(id bigint primary key ,price int not null,quantity int not null ,lastupdate timestamp)我想要SQL如果产品中没有ID，则从tmp_products插入产品。仅在（价格或数量）值更改时更新。

INSERT INTO products(id,price,quantity,lastupdate)
            SELECT  (id,price,quantity,lastupdate) FROM tmp_products
    ON CONFLICT (id) DO UPDATE SET
    price=EXCLUDED.price,
    quantity=EXCLUDED.quantity,
    lastupdate=EXCLUDED.lastupdate
    where price!=EXCLUDED.price or quantity!=EXCLUDED.quantity;

我遇到以下错误column reference "price" is ambiguous我想知道如何解决这个问题？

Answer 1

问题出在where子句中。您需要对列进行限定，以便明确：

INSERT INTO products(id,price,quantity,lastupdate)
SELECT id,price,quantity,lastupdate FROM tmp_products
ON CONFLICT (id) DO UPDATE SET
    price      = EXCLUDED.price,
    quantity   = EXCLUDED.quantity,
    lastupdate = EXCLUDED.lastupdate
WHERE products.price <> EXCLUDED.price OR products.quantity <> EXCLUDED.quantity;