Question

我正在获取两个选择查询的UNION，其中一个正在查询的表是一个临时表，以确保输出记录（因此临时表具有每个日期的预期输出，但默认值为0表示销售栏目

示例输出结果将是这样的：

T get_bytes(T const* t) { return getBytes(*t); }

Union根据行删除重复项，如何根据productID和transactionDate列删除重复项，删除Sale为0的重复项？

- 查询以下

ProductID  | Product Desc | TransactionDate | Sale
1011021    | SD DOG       | 2017-01-07      | 0
1011021    | SD DOG       | 2017-01-07      | $17
1011021    | SD DOG       | 2017-01-14      | 0
1011021    | SD DOG       | 2017-01-14      | $15
1011021    | SD DOG       | 2017-01-21      | $21
1011021    | SD DOG       | 2017-01-28      | 0
1011021    | SD DOG       | 2017-01-28      | $21

Answer 1

使用not exists从临时表中选择尚未包含在结果集中的行：

. . .
UNION ALL
SELECT tt.*
FROM temptable tt
WHERE NOT EXISTS (SELECT 1
                  FROM transactionproducts tp JOIN
                       transaction t
                       ON t.transactionID = tp.transactionID
                  WHERE tp.productId = tt.productId AND
                        t.transactionDate = tt.transactionDate
                 )
GROUP BY productID, productDesc, Sale, transactionDate 
ORDER BY transactionDate

Answer 2

这个怎么样：

SELECT transactionProducts.productID, products.productDesc, sum(salePrice) as Sale, transactionDate 
FROM products LEFT JOIN transactionProducts on products.productID = transactionProducts.productID 
LEFT JOIN transactions ON transactionProducts.transactionID = transactions.transactionID 
LEFT JOIN productCategory on productCategory.productID = products.productID 
LEFT JOIN categories on categories.categoryID = productCategory.categoryID
WHERE (transactionProducts.productID='123' AND transactions.transactionDate='2017-01-12' 
          AND sum(salePrice) > 0 )
Group by transactionProducts.productID, transactionDate
UNION select * from "temptable" group by productID, productDesc, Sale, transactionDate 
ORDER BY transactionDate

注意，我已将“AND sum（salePrice）＆gt; 0”添加到第一个SELECT WHERE子句中。

HTH

根据2列过滤来自UNION结果的重复项

2 个答案: