我有一些非常简单的 SQL，我可以尝试将其更改为 Linq 或 LLBLGEN

Question

我想做这样的事情...

SELECT DISTINCT T1.* 
FROM T1 
INNER JOIN T2 ON T2.ID1 = T1.ID1
INNER JOIN T3 ON T3.ID2 = T2.ID2
--FOLLOWING CAN BE ADDED MULTIPLE TIMES  (LOOPS IN C#?)
INNER JOIN T2 AS T2A ON T3.ID2 = T2A.ID2
INNER JOIN T1 AS T1A ON T1A.ID1 = T2A.ID1
--END MULTI
WHERE T1.ID1 = 1
AND T3.ID3 = 2
AND T3.ID4 = 3
--THE FOLLOWING CONDITIONS WILL ALSO BE FOR EVERY SET OF EXTRA JOINS (LOOPS IN C#?)
AND T1A.ID1 = 4
AND T1I.ID5 = 5
--END MULTI

...在 Linq 或 LLBLGen 代码中。任何帮助将不胜感激！

这是我迄今为止拥有的 LLBGen...

            IPredicateExpression filter = new PredicateExpression();
            filter.Add(ProductTypeOptionAttributeFields.OptionId == dl.Key);
            filter.AddWithAnd(ProductTypeOptionAttributeCombinationFields.ProductTypeId == DataSource.DataItem.ProductTypeId);
            filter.AddWithAnd(ProductTypeOptionAttributeCombinationFields.ProductId == DataSource.ProductID);
            bucket.PredicateExpression.Add(filter);

            bucket.Relations.Add(ProductTypeOptionAttributeEntity.Relations.ProductTypeOptionAttributeCombinationProfileEntityUsingProductTypeOptionAttributeId, JoinHint.Inner);
            bucket.Relations.Add(ProductTypeOptionAttributeCombinationProfileEntity.Relations.ProductTypeOptionAttributeCombinationEntityUsingProductTypeOptionAttributeCombinationId, JoinHint.Inner);

            var filtered = _dropdowns.Where(k => ((DropDownList)k.Value[1]).SelectedValue != "-1" && k.Key != dl.Key);
            foreach (var filteredDdl in filtered)
            {

                IPredicateExpression subFilter = new PredicateExpression();
                subFilter.AddWithAnd(ProductTypeOptionAttributeFields.AttributeId == int.Parse(((DropDownList)filteredDdl.Value[1]).SelectedValue));
                subFilter.AddWithAnd(ProductTypeOptionAttributeFields.OptionId == filteredDdl.Key);
                bucket.PredicateExpression.AddWithAnd(subFilter);                    
            }


            ProductTypeOptionAttributeCollection attrs = new ProductTypeOptionAttributeCollection();
            attrs.GetMulti(bucket.PredicateExpression, -1, null, bucket.Relations);

这是我想要的实际查询...

    SELECT DISTINCT PTOA.* 
    FROM ProductTypeOptionAttribute AS PTOA
    INNER JOIN ProductTypeOPtionAttributeCombinationProfile AS PTOACP ON PTOACP.ProductTypeOPtionAttributeID = PTOA.AttributeID
    INNER JOIN ProductTypeOPtionAttributeCombination AS PTOAC ON PTOAC.CombinationID = PTOACP.ProductTypeOptionAttributeCombinationID
    --FOLLOWING CAN BE ADDED MULTIPLE TIMES  (LOOPS IN C#?)
    INNER JOIN ProductTypeOPtionAttributeCombinationProfile AS PTOACP2 ON PTOAC.CombinationID = PTOACP2.ProductTypeOptionAttributeCombinationID
    INNER JOIN ProductTypeOPtionAttribute AS PTOA2 ON PTOACP2.ProductTypeOPtionAttributeID = PTOA2.AttributeID
--END MULTI
    WHERE PTOA.OptionID = 59
    AND PTOAC.ProductTypeID = 11

AND PTOAC.ProductID = 218
--THE FOLLOWING CONDITIONS WILL ALSO BE FOR EVERY SET OF EXTRA JOINS (LOOPS IN C#?)
AND PTOA2.AttributeID = 42
AND PTOA2.OptionID = 58
--END MULTI

干杯

Answer 1

LLBLGen 提示：

• 使用 SQL Server Profiler 查看发出的 SQL（在调用 GetMulti 后立即设置断点，然后观察跟踪）
• 您有很多复杂的 UI 登录和转换/转换可能会失败 - 我个人的偏好是将它们移动到单独的代码中
• 您不需要 JoinHint.Inner，因为这是默认设置
• （个人偏好），使用 RelationCollection 而不是存储桶。

我不完全理解你的情况（特别是多个连接到同一个表？），但这可能有效。我认为你想要 subFilter.AddWithOr 而不是 .AddWithAnd。

    IPredicateExpression filter = new PredicateExpression();
    filter.Add(ProductTypeOptionAttributeFields.OptionId == dl.Key);
    filter.AddWithAnd(ProductTypeOptionAttributeCombinationFields.ProductTypeId == DataSource.DataItem.ProductTypeId);
    filter.AddWithAnd(ProductTypeOptionAttributeCombinationFields.ProductId == DataSource.ProductID);

    IRelationCollection relations = new RelationCollection();
    relations.Add(ProductTypeOptionAttributeEntity.Relations.ProductTypeOptionAttributeCombinationProfileEntityUsingProductTypeOptionAttributeId);
    relations.Add(ProductTypeOptionAttributeCombinationProfileEntity.Relations.ProductTypeOptionAttributeCombinationEntityUsingProductTypeOptionAttributeCombinationId);

    var filtered = _dropdowns.Where(k => ((DropDownList)k.Value[1]).SelectedValue != "-1" && k.Key != dl.Key);
    foreach (var filteredDdl in filtered)
    {
        IPredicateExpression subFilter = new PredicateExpression();
        subFilter.AddWithOr(ProductTypeOptionAttributeFields.AttributeId == int.Parse(((DropDownList)filteredDdl.Value[1]).SelectedValue));
        subFilter.AddWithOr(ProductTypeOptionAttributeFields.OptionId == filteredDdl.Key);
        filter.AddWithAnd(subFilter);
    }

    ProductTypeOptionAttributeCollection attrs = new ProductTypeOptionAttributeCollection();
    attrs.GetMulti(filter, relations)

Answer 2

您提供的基本 SQL 查询应该很难在 LINQ 中重现。

从 T1 中的 t
其中 T1.ID == 1
选择;

如果您还没有使用它，请下载免费的 LINQPAD http://www.linqpad.net/ 它有很多帮助您快速了解情况的示例。