Command Object Methods - ADO.NET

Discussion

• Nihal   -Posted on 19 Oct 15
  Following are the methods of command object.
  ExecuteNonQuery: This method is used,If you are using insert,update,delete SQL statement.Its return type is Integer.This indicates the no of effected records.
  ExecuteReader: This method is used,If you are using Select SQL statement.Its return type is DataReader.
  ExecuteScalar: If you need to return a single value from a sql query, you
  can use the ExecuteScalar method. This method always returns the value
  of the first column from the first row. All other values are ignored. If the result set is empty it will return a null. Its return type is Object.
  
  ExecuteXMLReader: It returns XML formatted data. Returns a System.Xml.XmlReader
  Object.
  Example of ExecuteScalar Method
  public void CalculateSalary()
  {
  SqlConnection conn = new SqlConnection();
  SqlCommand cmd;
  conn.ConnectionString = ConfigurationManager.ConnectionStrings["connString"].ConnectionString;
  
  try
  {
  cmd = new SqlCommand();
  cmd.Connection = conn;
  cmd.CommandText = "SELECT SUM(SAL) SAL FROM EMPLOYEE";
  cmd.CommandType = CommandType.Text;
  conn.Open();
  
  int TotalSalary = Convert.ToInt32(cmd.ExecuteScalar());
  if(TotalSalary>0)
  {
  
  Label1.Text= "Total Salary is : " + TotalSalary.ToString());
  }
  
  cmd.Dispose();
  conn.Dispose();
  }
  catch (Exception ex)
  {
  Label1.Text =ex.Message;
  }
  }
  In the above example connection string is configured a for a Data Source in the App.config file
  

➨ Post your comment / Share knowledge