using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Data.SqlClient;namespace CommandNonQuery{    class Program    {        static void Main(string[] args)        {            SqlConnection conn = new SqlConnection(@"Data Source=.;Initial Catalog=Northwind;Integrated Security=True");            string sqlqry = @"select count(*) from employees";            string sqlins=@"insert into employees(firstname,lastname) values('tan','ding')";            string sqldel = @"delete from employees where firstname='tan' and lastname='ding'";            SqlCommand cmdqry = new SqlCommand(sqlqry, conn);            SqlCommand cmdnon = new SqlCommand(sqlins, conn);            try            {                conn.Open();                Console.WriteLine("Before Insert:Number of employees {0}\n", cmdqry.ExecuteScalar());                Console.WriteLine("Executing statement {0}", cmdnon.CommandText);                cmdnon.ExecuteNonQuery();                Console.WriteLine("After Insert:Number of employees {0}\n", cmdqry.ExecuteScalar());                cmdnon.CommandText = sqldel;                Console.WriteLine("Executing statement {0}", cmdnon.CommandText);                cmdnon.ExecuteNonQuery();                Console.WriteLine("After Delete:Number of employees {0}\n", cmdqry.ExecuteScalar());            }            catch (SqlException ex)            {                Console.WriteLine(ex.ToString());            }            finally            {                conn.Close();                Console.WriteLine("Connection closed.");            }            Console.ReadKey();        }    }}

示例说明：3条SQL语句存放在3个字符串变量中,首先是查询行，然后插入行，最后初始化其CommandText属性，设置删除语句，删除插入的行。