Question

我必须在视图中转换此查询：

SELECT col1,
       CONVERT(decimal(5, 4), SUM(Volume) / CONVERT(float, (
                                        SELECT SUM(Volume) 
                                        FROM A INNER JOIN B ON [..]
                                        WHERE A.CodA = @param1 AND CodB.[Year] = @param2))
        ) AS [VolPercent]
FROM A INNER JOIN B ON [..]
WHERE A.CodA = @param1 AND CodB.[Year] = @param2

因此，我必须使用外部查询中的相同clausule过滤子查询会是这样的：

SELECT col1,
       CONVERT(decimal(5, 4), SUM(Volume) / CONVERT(float, (
                                        SELECT SUM(Volume) 
                                        FROM A as C INNER JOIN B as D ON [..]
                                        WHERE C.CodA = A.CodA AND D.[Year] = B.[Year]))
        ) AS [VolPercent]
FROM A INNER JOIN B ON [..]

我该怎么做？有办法吗？

Answer 1

创建一个没有WHERE的视图，然后使用WHERE子句查询View应该得到完全相同的性能完全相同的结果。但是，您需要添加将在where子句中使用的列。所以是的，创建您的视图

create view MyView as
SELECT ACod.A, CodB.[Year],
       col1,
       CONVERT(decimal(5, 4), SUM(Volume) / CONVERT(float, (
                                        SELECT SUM(Volume) 
                                        FROM A as C INNER JOIN B as D ON [..]
                                        WHERE C.CodA = A.CodA AND D.[Year] = B.[Year]))
        ) AS [VolPercent]
FROM A INNER JOIN B ON [..]

然后您的查询是：

select * from MyView
where A = whatever
and [Year] = whatever

干杯 -

将View中的WHERE子句传播到子查询

1 个答案: