sqlserver快速删除大批量数据_sqlserver删除数据

go
 create table Department
 (
    DepId    int primary key identity(1,1),
    DepName    nvarchar(50)
 )
 insert into Department values('人事部')
 insert into Department values('开发部')

 insert into Department values('行政部')

这是个人的DBHelper类：
（要引用两个命名空间：
   using System.Data;
   using System.Data.SqlClient;）

public class DBHelper
    {
        static string Conns = "database=EmployeeSys;uid=sa;pwd=123456;server=.";
        /// <summary>
        /// 执行查询
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public static DataTable Table(string sql)
        {
            using (SqlConnection conn = new SqlConnection(Conns))
            {
                SqlDataAdapter sda = new SqlDataAdapter(sql, conn);
                DataTable dt = new DataTable();
                sda.Fill(dt);
                return dt;
            }
        }
        /// <summary>
        /// 执行增删改
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public static bool InsertOrDelete(string sql)
        {
            using (SqlConnection conn = new SqlConnection(Conns))
            {
                conn.Open();
                SqlCommand cmd = new SqlCommand(sql, conn);
                return cmd.ExecuteNonQuery() > 0;
            }
        }
    }

 string sql = string.Format(" select * from Department");
                DropDownList1.DataSource = DBHelper.Table(sql);
                DropDownList1.DataTextField = "DepName";
                DropDownList1.DataValueField = "DepId";
                DropDownList1.DataBind();

 int id=int.Parse(this.DropDownList1.SelectedItem.Value);