ADO.NET 在提交更改之前查看将发送到 SQL 服务器的查询

Question

假设我有代码

var Db = new MyEntities();

Random r = new Random();

// select a random customer out of the first 5
var customer = Db.Customers.OrderBy(c=>c.Id).Skip(r.Next(0, 5)).Take(1); 

foreach (var c in customer)
{
    c.WonPrice = true;
}


// How can I see here before saving the changes in order to see
// the query that will be sent to SQL server?
Db.SaveChanges();

当调用 SaveChanges() 时，如何在代码中看到生成的 SQL 语句？

Answer 1

如果这是 LINQ-to-SQL，那么您可以将 TextWriter 附加到 Db.Log：然后您通过 Db 执行的所有操作都将记录在其中。或者，您可以使用 mini-profiler 之类的工具，然后给 MyEntities 一个包装好的连接，即

public static DbConnection GetOpenConnection()
{
    // A SqlConnection, SqliteConnection ... or whatever
    var cnn = CreateRealConnection();

    // wrap the connection with a profiling connection that tracks timings 
    return new StackExchange.Profiling.Data.ProfiledDbConnection(cnn,
                                                MiniProfiler.Current);
}

...
using(var Db = new MyEntities(GetOpenConnection()))
{
    ...
}