LINQ 如何实现 in 与 not in

T-SQL的IN：



Select ProductID, ProductName, CategoryID

From dbo.Products

Where CategoryID in (1, 2)



T-SQL的NOT IN：



Select ProductID, ProductName, CategoryID

From dbo.Products

Where CategoryID not in (1, 2)



Or



Select ProductID, ProductName, CategoryID

From dbo.Products

Where not CategoryID in (1, 2)



LINQ的IN：



var queryResult = from p in db.Products

where (new int?[] {1,2}).Contains(p.CategoryID)

select p;



LINQ的IN解析成SQL：



SELECT [t0].[ProductID], [t0].[ProductName], [t0].[SupplierID], [t0].[CategoryID], [t0].[QuantityPerUnit], [t0].[UnitPrice], [t0].[UnitsInStock], [t0].[UnitsOnOrder], [t0].[ReorderLevel], [t0].[Discontinued] 

FROM [dbo].[Products]AS [t0]

WHERE [t0].[CategoryID] IN (@p0, @p1)



LINQ的NOT IN：



var queryResult = from p in db.Products

where ! (new int?[] {1,2}).Contains(p.CategoryID)

select p;



LINQ的NOT IN解析成SQL：



SELECT [t0].[ProductID], [t0].[ProductName], [t0].[SupplierID], [t0].[CategoryID], [t0].[QuantityPerUnit], [t0].[UnitPrice], [t0].[UnitsInStock], [t0].[UnitsOnOrder], [t0].[ReorderLevel], [t0].[Discontinued] 

FROM [dbo].[Products]AS [t0]

WHERE NOT [t0].[CategoryID] IN (@p0, @p1)