LINQ系列：LINQ to SQL Where条件

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1. 单一条件查询

var expr = context.Products    .Where(p => p.ProductName == "LINQ to SQL");

SELECT     [Extent1].[ProductID] AS [ProductID],     [Extent1].[CategoryID] AS [CategoryID],     [Extent1].[ProductName] AS [ProductName],     [Extent1].[UnitPrice] AS [UnitPrice],     [Extent1].[Discontinued] AS [Discontinued]    FROM [dbo].[Product] AS [Extent1]    WHERE N'LINQ to SQL' = [Extent1].[ProductName]

2. 组合条件查询

var expr = context.Products    .Where(p => p.ProductName == "LINQ to SQL" && p.UnitPrice > 10m);

SELECT     [Extent1].[ProductID] AS [ProductID],     [Extent1].[CategoryID] AS [CategoryID],     [Extent1].[ProductName] AS [ProductName],     [Extent1].[UnitPrice] AS [UnitPrice],     [Extent1].[Discontinued] AS [Discontinued]    FROM [dbo].[Product] AS [Extent1]    WHERE (N'LINQ to SQL' = [Extent1].[ProductName]) AND ([Extent1].[UnitPrice] > cast(10 as decimal(18)))

3. Like查询

var expr = from p in context.Products           where p.ProductName.StartsWith("LINQ")           select new { p.ProductID, p.ProductName };

SELECT     [Extent1].[ProductID] AS [ProductID],     [Extent1].[ProductName] AS [ProductName]    FROM [dbo].[Product] AS [Extent1]    WHERE [Extent1].[ProductName] LIKE N'LINQ%'

var expr = from p in context.Products           where p.ProductName.EndsWith("LINQ")           select new { p.ProductID, p.ProductName };

SELECT     [Extent1].[ProductID] AS [ProductID],     [Extent1].[ProductName] AS [ProductName]    FROM [dbo].[Product] AS [Extent1]    WHERE [Extent1].[ProductName] LIKE N'%LINQ'

var expr = from p in context.Products           where p.ProductName.Contains("LINQ")           select new { p.ProductID, p.ProductName };

SELECT     [Extent1].[ProductID] AS [ProductID],     [Extent1].[ProductName] AS [ProductName]    FROM [dbo].[Product] AS [Extent1]    WHERE [Extent1].[ProductName] LIKE N'%LINQ%'

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