Question

如何将此linq代码翻译成sql？

if (storeId > 1)
            {
                query = from p in query
                        where (p.StoreId == storeId) 
                        select p;
            }

如果storeId＆gt; 1我不想在SQL中进行WHERE比较。

UPDATE 以下是我想在SQL中做的事情：

SELECT * FROM test 
WHERE (
  (test.city = @city)
  AND 
  (test.price = @price)
  AND
  (
  IF (@storeId > 1)
    test.storeId = @storeId
  ELSE
    do not do anything 
  )
)

Answer 1

Select * from p where p.storeid = @storeid or @storeid > 1

Answer 2

查看您的代码，看起来您想要检索特定的storeId记录，如果storeId＆gt; 1.我还假设你的意思是如果storeId＆lt; = 1，你不想要一个where子句。如果我的假设是正确的，那么你所追求的SQL可能如下：

Select * from p where (@storeId > 1 and p.storeId = @storeId) or @storeId <= 1

在查看问题的更新后，此SQL应该适合您：

 SELECT * FROM test WHERE  test.city = @city AND test.price = @price 
 AND ((@storeId > 1 AND test.storeId = @storeId) or @storeId <=1)

请注意，如果@storeId＆lt; = 1，它将返回与City和Price匹配的所有记录。如果这不是您想要的，并且不希望在@storeId＆lt; = 1时返回任何记录，那么您可以删除最后的OR条件，如下所示：

 SELECT * FROM test WHERE  test.city = @city AND test.price = @price 
 AND (@storeId > 1 AND test.storeId = @storeId)

Answer 3

试

var queryresult = from p in query
                  where ((p.StoreId == storeId) && (storeId > 1)) 
                        || (storeId <= 1)
                  select p;

SQL if where else

3 个答案: