05장 ADO.Net 카테고리 추가,리스트,뷰(CategoryAdd,List,View)

- 6가지 패던을 머리에 정리 -  입력 : Connection -> Command -> ExecuteNonQuer() 출력 : Connection -> Command -> DataReader() -> DataBind() 상세 : Connection -> Command -> DataReader() -> Read() 수정 삭제  검색 동기식(Synchronous) : 하나만 처리 비동기식(Asynchronous) : 다중처리, AJAX

CategoryAdd 카테고리 추가.Cs

using System; using System.Collections; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using System.Data.SqlClient; public partial class Category_FrmCategoryAdd : System.Web.UI.Page {     protected void Page_Load(object sender, EventArgs e)     {     }     protected void btnCategoryAdd_Click(object sender, EventArgs e)     {         //변수선언부         string insertQuery =           //"Insert into Categories(CategoryName) Values('컴퓨터')";         //매개변수 처리 : 컴퓨터         //   "Insert Into Categories(CategoryName)                               values('" + txtCategoryName.Text + "')";         //최적으로 사용하는 방법[추천] Named 매개변수 처리 : @변수         "Insert Into Categories(CategoryName) Values(@CategoryName)";         //[1] 커넥션         SqlConnection con = new SqlConnection(                 ConfigurationManager.ConnectionStrings                       ["ConnectionString"].ConnectionString);              //[2] 커맨드         SqlCommand cmd = new SqlCommand(insertQuery, con);         cmd.CommandType = CommandType.Text;         //파라미터 추가         cmd.Parameters.AddWithValue                   ("@CategoryName", txtCategoryName.Text);         //[3] 실행         try         {             con.Open();             cmd.ExecuteNonQuery();         }         catch (SqlException se)         {             lblError.Text = se.Message; //에러메시지 출력                     }         finally         {             if (con.State == ConnectionState.Open)             {                 con.Close(); //연결상태라면, 닫기             }         }         con.Close();     } }

CategoryList 카테고리 리스트.Cs

using System; using System.Collections; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using System.Data.SqlClient; public partial class Category_FrmCategoryList : System.Web.UI.Page {     protected void Page_Load(object sender, EventArgs e)     {         if (!Page.IsPostBack)         {             DisplayData();             DisplayCount();         }         }      //Categories 레코드 갯수      private void DisplayCount()     {         SqlConnection con = new SqlConnection                  (ConfigurationManager.ConnectionStrings                   ["ConnectionString"].ConnectionString);         con.Open();         SqlCommand cmd = new SqlCommand                 ("Select Count(*) From Categories", con);         cmd.CommandType = CommandType.Text;         lblCount.Text = cmd.ExecuteScalar().ToString();         con.Close();     }     //Categories 출력     private void DisplayData()     {         //[1] 커넥션         SqlConnection con = new SqlConnection              (ConfigurationManager.ConnectionStrings                ["ConnectionString"].ConnectionString);         con.Open(); //열기               //[2] 커맨드         SqlCommand cmd = new SqlCommand                            ("Select *From Categories", con);         cmd.CommandType = CommandType.Text;                 //[3]데이터 리더         SqlDataReader dr = cmd.ExecuteReader();         //[4]바인딩         ctlCategoryList.DataSource = dr;         ctlCategoryList.DataBind();         //[닫기]         dr.Close();         con.Close();     } }

CategoryView 카테고리 View.Cs

using System; using System.Collections; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using System.Data.SqlClient; public partial class Category_FrmCategoryView : System.Web.UI.Page {     protected void Page_Load(object sender, EventArgs e)     {     }     protected void btnCategoryID_Click(object sender, EventArgs e)     {         //커넥연 (데이터베이스연결)         SqlConnection conn = new SqlConnection                  (ConfigurationManager.ConnectionStrings                    ["ConnectionString"].ConnectionString);         conn.Open();         //커맨드 : 단일 레코드         SqlCommand cmd = new SqlCommand(             "Select *From Categories Where                         CategoryID = @CategoryID", conn);         cmd.CommandType = CommandType.Text;         //파라미터 추가         cmd.Parameters.AddWithValue("@CategoryID", txtCategoryID.Text);         //데이터 리더         SqlDataReader dr = cmd.ExecuteReader();                 //Read() --> 문자열 정수형 인덱서 또는 GetXXX() 메서드로 읽어오기         while (dr.Read())         {             //문자열 인덱서              this.txtCategoryID.Text = dr["CategoryID"].ToString();                         //정수(서수)형 처리               this.lblCategoryName.Text = dr[1].ToString();             if (dr["SuperCategory"] != null) //널 값처리             {                 this.lblSuperCategoryName.Text = dr                                 ["SuperCategory"].ToString();             }             this.lblCategoryAlign.Text = dr["Align"].ToString();         }         dr.Close();         conn.Close();    } }