把添加的新行保存到数据库

// 把添加的新行保存到数据库

// PersistAdds.cs

using System;

using System.Data;

using System.Data.SqlClient;

namespace Ch13

{

    class PersistAdds

    {

        static void Main( string[] args)

        {

            string strConn = "server=.\\MSSQL2012;integrated security=true;database=Northwind";

            string qry = "select * from employees where employeeid=1" ;

            string ins = "insert into employees(firstname,lastname,titleofcourtesy,city,country)"

                + " values(@fname,@lname,@title,@city,@country)" ;

            SqlConnection conn = new SqlConnection(strConn);

            try

            {

                SqlDataAdapter da = new SqlDataAdapter();

                da.SelectCommand = new SqlCommand(qry, conn);

                DataSet ds = new DataSet();

                da.Fill(ds, "emp" );

                DataTable dt = ds.Tables[ "emp" ];

               

                Console.WriteLine( "插入前" );

                foreach (DataRow row in dt.Rows)

                {

                    Console.WriteLine( "{0} {1} {2}"

                        , row[ "firstname" ].ToString().PadRight(15)

                        , row[ "lastname" ].ToString().PadRight(15)

                        , row[ "city" ]);

                }

                // 添加新行

                DataRow newrow = dt.NewRow();

                newrow[ "firstname" ] = "张" ;

                newrow[ "lastname" ] = "三" ;

                newrow[ "titleofcourtesy" ] = "先生" ;

                newrow[ "city" ] = "深圳" ;

                newrow[ "country" ] = "中国" ;

                dt.Rows.Add(newrow);

                // 此时数据并没有写入到数据库，而是内存表中

                Console.WriteLine( "插入后" );

                foreach (DataRow row in dt.Rows)

                {

                    Console.WriteLine( "{0} {1} {2}"

                        ,row[ "firstname" ].ToString().PadRight(15)

                        ,row[ "lastname" ].ToString().PadRight(15)

                        ,row[ "city" ]);

                }

                // 创建SqlCommand

                SqlCommand cmd = new SqlCommand(ins, conn);

                cmd.Parameters.Add( "@fname" ,   SqlDbType.NVarChar, 10, "firstname" );

                cmd.Parameters.Add( "@lname" ,   SqlDbType.NVarChar, 20, "lastname" );

                cmd.Parameters.Add( "@title" ,   SqlDbType.NVarChar, 25, "titleofcourtesy" );

                cmd.Parameters.Add( "@city" ,    SqlDbType.NVarChar, 15, "city" );

                cmd.Parameters.Add( "@country" , SqlDbType.NVarChar, 15, "country" );

                da.InsertCommand = cmd;

                da.Update(ds, "emp" );

                // 此时数据真正写入到数据库

            }

            catch( Exception ex)

            {

                Console.WriteLine( "出错了:" + ex);

            }

            finally

            {

                conn.Close();

                Console.ReadLine();

            }

        }

    }

}

----------

插入前

Nancy           Davolio         Seattle

插入后

Nancy           Davolio         Seattle

张               三               深圳

来自为知笔记(Wiz)