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

我刚刚做了这个:

IQueryable<Product> query = EntitySet.Where(p => p.Id == id);
Debug.WriteLine(query);

结果显示在Output:

SELECT 
    [Extent1].[Id] AS [Id], 
    [Extent1].[Code] AS [Code], 
    [Extent1].[Name] AS [Name], 
    [Extent2].[Id] AS [Id1], 
    [Extent2].[FileName] AS [FileName], 
    FROM  [dbo].[Products] AS [Extent1]
    INNER JOIN [dbo].[PersistedFiles] AS [Extent2] ON [Extent1].[PersistedFileId] = [Extent2].[Id]
    WHERE [Extent1].[Id] = @p__linq__0

其他回答

EF Core 5.0+

这个期待已久的功能在EF Core 5.0中可用!这是每周的状态更新:

var query = context.Set<Customer>().Where(c => c.City == city); Console.WriteLine(query.ToQueryString()) results in this output when using the SQL Server database provider: DECLARE p0 nvarchar(4000) = N'London'; SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region] FROM [Customers] AS [c] WHERE [c].[City] = @__city_0 Notice that declarations for parameters of the correct type are also included in the output. This allows copy/pasting to SQL Server Management Studio, or similar tools, such that the query can be executed for debugging/analysis.

哦吼! !

(注意:你需要使用Microsoft.EntityFrameworkCore;)

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();

在我的EF 6+的情况下,而不是在立即窗口中使用这个来查找查询字符串:

var sql = ((System.Data.Entity.Core.Objects.ObjectQuery)query).ToTraceString();

我最终不得不使用这个来获得生成的SQL命令:

var sql = ((System.Data.Entity.Infrastructure.DbQuery<<>f__AnonymousType3<string,string,string,short,string>>)query).ToString();

当然,您的匿名类型签名可能有所不同。

HTH.

实体框架4解决方案

这里的大多数答案都是ef6特异性的。这里有一个给那些还在使用EF4的人。

这个方法替换了@p__linq__0/etc。参数的实际值,所以您可以复制并粘贴输出到SSMS并运行它或调试它。

    /// <summary>
    /// Temporary debug function that spits out the actual SQL query LINQ is generating (with parameters)
    /// </summary>
    /// <param name="q">IQueryable object</param>
    private string Debug_GetSQLFromIQueryable<T>(IQueryable<T> q)
    {
        System.Data.Objects.ObjectQuery oq = (System.Data.Objects.ObjectQuery)q;
        var result = oq.ToTraceString();
        List<string> paramNames = new List<string>();
        List<string> paramVals = new List<string>();
        foreach (var parameter in oq.Parameters)
        {
            paramNames.Add(parameter.Name);
            paramVals.Add(parameter.Value == null ? "NULL" : ("'" + parameter.Value.ToString() + "'"));
        }
        //replace params in reverse order, otherwise @p__linq__1 incorrectly replaces @p__linq__10 for instance
        for (var i = paramNames.Count - 1; i >= 0; i--)
        {
            result = result.Replace("@" + paramNames[i], paramVals[i]);
        }
        return result;
    }

在EF 4.1中可以执行以下操作:

var result = from x in appEntities
             where x.id = 32
             select x;

System.Diagnostics.Trace.WriteLine(result .ToString());

这将为您提供生成的SQL。