如何查看实体框架生成的SQL ?

(在我的特殊情况下,我使用mysql提供商-如果它重要)


当前回答

如果您正在使用DbContext,您可以执行以下操作来获取SQL:

var result = from i in myContext.appEntities
             select new Model
             {
                 field = i.stuff,
             };
var sql = result.ToString();

其他回答

在不更改代码的情况下,使查询始终方便 将它添加到你的DbContext中,并在visual studio的输出窗口中检查它。

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        Database.Log = (query)=> Debug.Write(query);
    }

类似于@Matt Nibecker的答案,但有了这个答案,你不必每次需要查询时都将它添加到当前代码中。

有两种方法:

To view the SQL that will be generated, simply call ToTraceString(). You can add it into your watch window and set a breakpoint to see what the query would be at any given point for any LINQ query. You can attach a tracer to your SQL server of choice, which will show you the final query in all its gory detail. In the case of MySQL, the easiest way to trace the queries is simply to tail the query log with tail -f. You can learn more about MySQL's logging facilities in the official documentation. For SQL Server, the easiest way is to use the included SQL Server profiler.

对我来说,使用EF6和Visual Studio 2015,我在即时窗口中输入查询,它给了我生成的SQL语句

适用于EF 6.0及以上: 对于那些想要了解更多关于日志功能并添加到已经给出的一些答案的人。

现在可以记录从EF发送到数据库的任何命令。查看从EF 6生成的查询。x,使用DBContext.Database.Log属性

记录什么

- SQL for all different kinds of commands. For example: - Queries, including normal LINQ queries, eSQL queries, and raw queries from methods such as SqlQuery. - Inserts, updates, and deletes generated as part of SaveChanges - Relationship loading queries such as those generated by lazy loading - Parameters - Whether or not the command is being executed asynchronously - A timestamp indicating when the command started executing - Whether or not the command completed successfully, failed by throwing an exception, or, for async, was canceled - Some indication of the result value - The approximate amount of time it took to execute the command. Note that this is the time from sending the command to getting the result object back. It does not include time to read the results.

例子:

using (var context = new BlogContext()) 
{ 
    context.Database.Log = Console.Write; 

    var blog = context.Blogs.First(b => b.Title == "One Unicorn"); 

    blog.Posts.First().Title = "Green Eggs and Ham"; 

    blog.Posts.Add(new Post { Title = "I do not like them!" }); 

    context.SaveChangesAsync().Wait(); 
}

输出:

SELECT TOP (1)
    [Extent1].[Id] AS [Id],
    [Extent1].[Title] AS [Title]
    FROM [dbo].[Blogs] AS [Extent1]
    WHERE (N'One Unicorn' = [Extent1].[Title]) AND ([Extent1].[Title] IS NOT NULL)
-- Executing at 10/8/2013 10:55:41 AM -07:00
-- Completed in 4 ms with result: SqlDataReader

SELECT
    [Extent1].[Id] AS [Id],
    [Extent1].[Title] AS [Title],
    [Extent1].[BlogId] AS [BlogId]
    FROM [dbo].[Posts] AS [Extent1]
    WHERE [Extent1].[BlogId] = @EntityKeyValue1
-- EntityKeyValue1: '1' (Type = Int32)
-- Executing at 10/8/2013 10:55:41 AM -07:00
-- Completed in 2 ms with result: SqlDataReader

UPDATE [dbo].[Posts]
SET [Title] = @0
WHERE ([Id] = @1)
-- @0: 'Green Eggs and Ham' (Type = String, Size = -1)
-- @1: '1' (Type = Int32)
-- Executing asynchronously at 10/8/2013 10:55:41 AM -07:00
-- Completed in 12 ms with result: 1

INSERT [dbo].[Posts]([Title], [BlogId])
VALUES (@0, @1)
SELECT [Id]
FROM [dbo].[Posts]
WHERE @@ROWCOUNT > 0 AND [Id] = scope_identity()
-- @0: 'I do not like them!' (Type = String, Size = -1)
-- @1: '1' (Type = Int32)
-- Executing asynchronously at 10/8/2013 10:55:41 AM -07:00
-- Completed in 2 ms with result: SqlDataReader

记录到外部文件:

using (var context = new BlogContext()) 
{  
    using (var sqlLogFile = new StreamWriter("C:\\temp\\LogFile.txt"))
    {          
         context.Database.Log = sqlLogFile.Write;     
         var blog = context.Blogs.First(b => b.Title == "One Unicorn"); 
         blog.Posts.First().Title = "Green Eggs and Ham"; 
         context.SaveChanges();
   }
}

更多信息在这里:记录和拦截数据库操作

我正在做集成测试,需要在实体框架核心2.1中调试生成的SQL语句,所以我使用DebugLoggerProvider或ConsoleLoggerProvider,如下所示:

[Fact]
public async Task MyAwesomeTest
    {
        //setup log to debug sql queries
        var loggerFactory = new LoggerFactory();
        loggerFactory.AddProvider(new DebugLoggerProvider());
        loggerFactory.AddProvider(new ConsoleLoggerProvider(new ConsoleLoggerSettings()));

        var builder = new DbContextOptionsBuilder<DbContext>();
        builder
            .UseSqlServer("my connection string") //"Server=.;Initial Catalog=TestDb;Integrated Security=True"
            .UseLoggerFactory(loggerFactory);

        var dbContext = new DbContext(builder.Options);

        ........

下面是Visual Studio控制台的输出示例: