如何：顯示LINQ to SQL 命令

使用 GetCommand 來顯示 SQL 命令和其他資訊。

範例

在下列範例中，控制台視窗會顯示查詢的輸出，後面接著產生的 SQL 命令、命令類型，以及連接類型。

// using System.Data.Common;
Northwnd db = new Northwnd(@"c:\northwnd.mdf");

var q =
    from cust in db.Customers
    where cust.City == "London"
    select cust;

Console.WriteLine("Customers from London:");
foreach (var z in q)
{
    Console.WriteLine($"\t {z.ContactName}");
}

DbCommand dc = db.GetCommand(q);
Console.WriteLine($"\nCommand Text: \n{dc.CommandText}");
Console.WriteLine($"\nCommand Type: {dc.CommandType}");
Console.WriteLine($"\nConnection: {dc.Connection}");

Console.ReadLine();

' Imports System.Data.Common

Dim db As New Northwnd("c:\northwnd.mdf")

Dim q = _
From cust In db.Customers _
Where cust.City = "London" _
Select cust

Console.WriteLine("Customers from London:")
For Each z As Customer In q
    Console.WriteLine(vbTab & z.ContactName)
Next

Dim dc As DbCommand = db.GetCommand(q)
Console.WriteLine(vbNewLine & "Command Text: " & vbNewLine & dc.CommandText)
Console.WriteLine(vbNewLine & "Command Type: {0}", dc.CommandType)
Console.WriteLine(vbNewLine & "Connection: {0}", dc.Connection)

Console.ReadLine()

輸出如下所示：

Customers from London:  
    Thomas Hardy  
    Victoria Ashworth  
    Elizabeth Brown  
    Ann Devon  
    Simon Crowther  
    Marie Bertrand  
    Hari Kumar  
    Dominique Perrier  

Command Text:  
SELECT [t0].[CustomerID], [t0].[CompanyName], [t0].[ContactName], [t0].[ContactT  
itle], [t0].[Address], [t0].[City], [t0].[Region], [t0].[PostalCode], [t0].[Coun  
try], [t0].[Phone], [t0].[Fax]  
FROM [dbo].[Customers] AS [t0]  
WHERE [t0].[City] = @p0  
  
Command Type: Text  
  
Connection: System.Data.SqlClient.SqlConnection  

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