SqlTriggerContext Class

Reference

Definition

Namespace:: Microsoft.SqlServer.Server

Assembly:: System.Data.dll

Important

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Provides contextual information about the trigger that was fired.

public ref class SqlTriggerContext sealed

public sealed class SqlTriggerContext

type SqlTriggerContext = class

Public NotInheritable Class SqlTriggerContext

Inheritance: Object
SqlTriggerContext

Examples

The following example shows a SqlTriggerContext object being used to determine if an Insert action occurred. If a row was inserted into the user's table, the user name and real name are retrieved from the inserted row and then added to the UserNameAudit table.

[SqlTrigger(Name = @"UsersAudit", Target = "[dbo].[users]", Event = "FOR INSERT")]
public static void UsersAudit()
{
   // Get the trigger context.
   string userName;
   string realName;
   SqlCommand command;
   SqlTriggerContext triggContext = SqlContext.TriggerContext;
   SqlDataReader reader;

   switch (triggContext.TriggerAction)
   {
      case TriggerAction.Insert:

      // Retrieve the connection that the trigger is using.
      using (SqlConnection connection
         = new SqlConnection(@"context connection=true"))
      {
         connection.Open();

         // Get the inserted row.
         command = new SqlCommand(@"SELECT * FROM INSERTED;",
                                  connection);

         // Get the user name and real name of the inserted user.
         reader = command.ExecuteReader();
         reader.Read();
         userName = (string)reader[0];
         realName = (string)reader[1];
         reader.Close();

         // Insert the user name and real name into the auditing table.
         command = new SqlCommand(@"INSERT [dbo].[UserNameAudit] (userName, realName) "
                  + @"VALUES (@userName, @realName);", connection);

         command.Parameters.Add(new SqlParameter("@userName", userName));
         command.Parameters.Add(new SqlParameter("@realName", realName));

         command.ExecuteNonQuery();
      }

      break;
   }
}

<SqlTrigger(Name:="UsersAudit", Target:="[dbo].[users]", Event:="FOR INSERT")> _
Public Shared Sub UsersAudit()
        
   Dim command As SqlCommand
   Dim triggContext As SqlTriggerContext
   Dim reader As SqlDataReader
   Dim userName As String
   Dim realName As String

         
   ' Get the trigger context.
   triggContext = SqlContext.TriggerContext        

   Select Case triggContext.TriggerAction
           
      Case TriggerAction.Insert

         ' Retrieve the connection that the trigger is using.
         Using connection As New SqlConnection("context connection=true")
            connection.Open()

            ' Get the inserted row.
            command = new SqlCommand("SELECT * FROM INSERTED;", connection)
            
            ' Get the user name and real name of the inserted user.                
            reader = command.ExecuteReader()
            reader.Read()
            userName = CType(reader(0), String)
            realName = CType(reader(1), String)

            reader.Close()

            ' Insert the user name and real name into the auditing table.
            command = New SqlCommand("INSERT [dbo].[UserNameAudit] (userName, realName) " & _
               "VALUES (@userName, @realName);", connection)

            command.Parameters.Add(new SqlParameter("@userName", userName))
            command.Parameters.Add(new SqlParameter("@realName", realName))
                 
            command.ExecuteNonQuery()
                 
          End Using
         
   End Select

End Sub

Remarks

The contextual information provided includes the type of action that caused the trigger to fire, which columns were modified in an UPDATE operation, and, in the case of a data definition language (DDL) trigger, an XML EventData structure (see Transact-SQL Reference) that describes the triggering operation.

An instance of SqlTriggerContext is available from the SqlContext class, when the code is running inside a trigger through the TriggerContext property.

Properties

ColumnCount	Gets the number of columns contained by the data table bound to the trigger. This property is read-only.
EventData	Gets the event data specific to the action that fired the trigger.
TriggerAction	Indicates what action fired the trigger.

Methods

IsUpdatedColumn(Int32)

Returns true if a column was affected by an INSERT or UPDATE statement.

Applies to

Delen via