dotConnect for SQL Server Documentation
Devart.Data.SqlServer Namespace / SqlCommand Class
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    SqlCommand Class
    In This Topic
    Represents a SQL statement or stored procedure to execute against SQL Server.
    Syntax
    Remarks
    The SqlCommand class provides the following methods for executing commands against the SQL Server database:
    Item Description
    ExecuteReader Executes commands that return rows.
    Devart.Common.DbCommandBase.ExecutePageReader Returns a specific subset of rows when paging through the results of a query.
    ExecuteNonQuery Executes SQL commands such as INSERT, DELETE, UPDATE.
    ExecuteScalar Retrieves a single value (for example, an aggregate value) from a data source.

    If execution of the command results in a fatal SqlException, the SqlConnection may close. However, the user can reopen the connection and continue.

    This class supports cross-form data binding with the InterForm Technology.

    Example
    The following example uses the ExecuteReader method of SqlCommand, along with SqlDataReader and SqlConnection, to select rows from a table.
    public void ReadMyData(string myConnString)
    {
      string mySelectQuery = "SELECT DeptNo, DName FROM Test.Dept";
      SqlConnection myConnection = new SqlConnection(myConnString);
      SqlCommand myCommand = new SqlCommand(mySelectQuery,myConnection);
      myConnection.Open();
      SqlDataReader myReader = myCommand.ExecuteReader();
      try
      {
        while (myReader.Read())
        {
          Console.WriteLine(myReader.GetInt32(0).ToString() + ", " + myReader.GetString(1));
        }
      }
      finally
      {
      // always call Close when done reading.
      myReader.Close();
      // always call Close when done reading.
      myConnection.Close();
      }
    }
    Public Sub ReadMyData(myConnString As String)
      Dim mySelectQuery As String = "SELECT DeptNo, DName FROM Test.Dept"
      Dim myConnection As New SqlConnection(myConnString)
      Dim myCommand As New SqlCommand(mySelectQuery, myConnection)
      myConnection.Open()
      Dim myReader As SqlDataReader = myCommand.ExecuteReader()
      Try
        While myReader.Read()
          Console.WriteLine(myReader.GetInt32(0).ToString() + ", " _
            + myReader.GetString(1))
        End While
      Finally
          ' always call Close when done reading.
          myReader.Close()
          ' always call Close when done with connection.
          myConnection.Close()
      End Try
    End Sub
    Inheritance Hierarchy

    System.Object
       System.MarshalByRefObject
          System.ComponentModel.Component
             System.Data.Common.DbCommand
                Devart.Common.DbCommandBase
                   Devart.Data.SqlServer.SqlCommand

    See Also