C# OleDbConnection.Close方法代码示例

        public DataSet Select(string selstr)
        {
            DataSet ds = new DataSet();

            OleDbConnection conn = new OleDbConnection();
            conn.ConnectionString = @"Provider=Microsoft.Jet.OLEDB.4.0;" +
                "Data Source =" + DBPath;

            try
            {
                conn.Open();
                OleDbDataAdapter da = new OleDbDataAdapter(selstr, conn);
                da.Fill(ds);
            }
            catch (Exception)
            {
                conn.Close();
            }
            finally
            {
                conn.Close();
            }

            return ds;
        }

    protected void onClick_login(object sender, EventArgs e)
    {
        connection = new OleDbConnection(path);
        connection.Open();

        cmd = new OleDbCommand("SELECT COUNT(*) FROM tblProfiles WHERE user_name = '" + inputUsername.Text + "';", connection);
        cmd.ExecuteNonQuery();

        int compareUsername = Convert.ToInt32(cmd.ExecuteScalar().ToString());

        connection.Close();

        if (compareUsername == 1)
        {
            connection.Open();

            cmd = new OleDbCommand("SELECT user_password FROM tblProfiles WHERE user_name = '" + inputUsername.Text + "';", connection);
            cmd.ExecuteNonQuery();

            string comparePassword = cmd.ExecuteScalar().ToString();

            connection.Close();

            if (comparePassword == inputPassword.Text)
            {
                Session["username"] = inputUsername.Text;
                Server.Transfer("main.aspx");
            }
            else
                errorPassword.Visible = true;
        }
        else
            errorUsername.Visible = true;
    }

        private void MigrateExcelFile(string fileName,string excel_column_range,string tempTable)
        {
            string virtualColumns = "null as user_id";
            OleDbCommand command = default(OleDbCommand);
            OleDbDataReader rdr = default(OleDbDataReader);
            OleDbConnection conn = default(OleDbConnection);
            try
            {
                conn = new OleDbConnection(string.Format(excelConnectionString, fileName));
                conn.Open();
                if (virtualColumns != "") virtualColumns += ",";
                command = conn.CreateCommand();
                command.CommandText = string.Format("Select {0} * From [{1}]",virtualColumns, excel_column_range);
                command.CommandType = CommandType.Text;
                rdr = command.ExecuteReader();
                if (rdr.HasRows)
                {
                    SqlBulkCopy sqlBulk = new SqlBulkCopy(dbConnection.ConnectionString);
                    sqlBulk.DestinationTableName = tempTable;
                    sqlBulk.WriteToServer(rdr);
                    rdr.Close();
                }
                conn.Close();
            }
            catch (Exception ex)
            {
                if (conn.State == ConnectionState.Open) conn.Close();
                throw ex;
            };


        }

        /// <summary>
        /// ���뵽dataset
        /// </summary>
        /// <param name="Path"></param>
        /// <param name="sheetname"></param>
        /// <returns></returns>
        public DataSet Getexcelds(string Path, String sheetname)
        {
            string strConn = string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source='" + Path + "';Extended Properties='Excel 8.0;HDR=YES;IMEX=1'");//��һ����Ϊ��
            OleDbConnection conn = new OleDbConnection(strConn);
            conn.Open();
            try
            {
                string strExcel = "select * from [" + sheetname + "]";
                if (sheetname.IndexOf('$') < 0)//if it have not $
                {
                    strExcel = "select * from[" + sheetname + "$]";
                }
                OleDbDataAdapter da = new OleDbDataAdapter(strExcel, strConn);
                DataSet ds = new DataSet();
                da.Fill(ds, "��˾Ա��");
                conn.Close();
                return ds;

            }
            catch (Exception error)
            {
                return null;
            }
            finally
            {
                conn.Close();
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            string chaine = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:/Users/dhib/Desktop/Professeur.accdb";
            OleDbConnection con = new OleDbConnection(chaine);
            OleDbCommand cmd = con.CreateCommand();
            cmd.CommandText = "select * from module1";
            try
            {
                con.Open();
                OleDbDataReader dr = cmd.ExecuteReader();
                dataGridView1.Rows.Clear();
                while (dr.Read())
                {
                    dataGridView1.Rows.Add(dr.GetValue(1), dr.GetValue(2), dr.GetValue(3), dr.GetValue(4),dr.GetValue(0));
                }
                dr.Close();
                con.Close();
                
            }
            catch (Exception ex) { MessageBox.Show("Erreur : " + ex.Message); con.Close(); }



          //  dataGridView1.CellClick += new DataGridViewCellEventHandler(dataGridView1_CellClick);
        }

        protected void Page_Load(object sender, EventArgs e)
        {
            if (Session["oturumid"] == null)
                Response.Redirect("giris.aspx");
            else if (Session["oturumdurum"].ToString() == "0")
                Response.Redirect("uyepaneli.aspx");
            else if (Request.QueryString["mid"] == null|| Request.QueryString["mid"] == "")
                Response.Redirect("adminpaneli.aspx");
            else
            {
                string mid = Request.QueryString["mid"];

                OleDbConnection cnn = new OleDbConnection("Provider=Microsoft.Jet.Oledb.4.0; Data Source=" + Server.MapPath("App_Data/database.mdb"));
                cnn.Open();
                OleDbCommand cmd = new OleDbCommand("select * from mesajlar where mesajid=" + mid, cnn);
                OleDbDataReader rdr = cmd.ExecuteReader();
                if(rdr.Read()==false)
                {
                    cnn.Close();
                    Response.Redirect("adminpaneli.aspx");
                }                    
                else
                {
                    Label2.Text = rdr[1].ToString();
                    Label4.Text = rdr[2].ToString();
                    Label6.Text = rdr[3].ToString();
                    Label7.Text = rdr[4].ToString();
                }

                if(cnn.State==System.Data.ConnectionState.Open)
                cnn.Close();
            }
        }

        public DataSet Excel2003ToDataSet(string Path)
        {
            OleDbConnection conn = null;
            try
            {
                string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + Path + ";" + "Extended Properties=Excel 8.0;";
                conn = new OleDbConnection(strConn);
                conn.Open();
                System.Data.DataTable dtSheet = conn.GetOleDbSchemaTable(System.Data.OleDb.OleDbSchemaGuid.Tables, null);
                string tableName = dtSheet.Rows[0][2].ToString();

                string strExcel = "";
                OleDbDataAdapter myCommand = null;
                DataSet ds = null;
                strExcel = "select * from [" + tableName + "]";
                myCommand = new OleDbDataAdapter(strExcel, strConn);
                ds = new DataSet();
                myCommand.Fill(ds, tableName);
                conn.Close();
                conn = null;
                return ds;
            }
            catch (Exception ex)
            {
                if (conn != null && conn.State == ConnectionState.Open)
                    conn.Close();
                conn = null;
                throw;
            }
        }

        /// <summary>
        /// 执行查询
        /// </summary>
        /// <param name="ServerFileName">xls文件路径</param>
        /// <param name="SelectSQL">查询SQL语句</param>
        /// <returns>DataSet</returns>
        public static System.Data.DataSet SelectFromXLS(string ServerFileName, string SelectSQL)
        {

            string connStr = "Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = '" + ServerFileName + "';Extended Properties=Excel 8.0";
            OleDbConnection conn = new OleDbConnection(connStr);
            OleDbDataAdapter da = null;
            System.Data.DataSet ds = new System.Data.DataSet();
            try
            {
                conn.Open();
                da = new OleDbDataAdapter(SelectSQL, conn);
                da.Fill(ds, "SelectResult");
            }
            catch (Exception e)
            {
                conn.Close();
                throw e;
            }
            finally
            {
                conn.Close();
            }
            return ds;

        }

        private void button2_Click(object sender, EventArgs e)
        {
            string chaine = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:/Users/dhib/Desktop/Professeur.accdb";
            OleDbConnection con = new OleDbConnection(chaine);

            OleDbCommand cmd = con.CreateCommand();
            cmd.CommandText = "Insert into enseignant(login,mdp,nom,prenom,grade) values ('" + txt_insc_login.Text + "','" + txt_insc_password.Text + "','" + txt_insc_family.Text + "','" + txt_insc_name.Text + "','" + txt_insc_grade.Text + "')";
            try
            {
                con.Open();
                cmd.ExecuteNonQuery();
                MessageBox.Show("Ajout Réussi");
                txt_insc_login.Text = "";
                txt_insc_password.Text = "";
                txt_insc_family.Text = "";
                txt_insc_name.Text = "";
                txt_insc_grade.Text = "";
                con.Close();
                new Form1().Show();
                this.Hide();

            }catch(Exception ex)
            { MessageBox.Show("Erreur" + ex.Message);
            con.Close();
            }
        }

        //Create an Excel file with 2 columns: name and score:
        //Write a program that reads your MS Excel file through
        //the OLE DB data provider and displays the name and score row by row.

        static void Main()
        {
            OleDbConnection dbConn = new OleDbConnection(@"Provider=Microsoft.ACE.OLEDB.12.0;" +
            @"Data Source=D:\Telerik\DataBases\HW\ADONET\06. ReadExcel\Table.xlsx;Extended Properties=""Excel 12.0 XML;HDR=Yes""");
            OleDbCommand myCommand = new OleDbCommand("select * from [Sheet1$]", dbConn);
            dbConn.Open();
            //First way
            //using (dbConn) - I think it is better to use dbConn in using clause, but for the demo issues i dont use using.
            //{
            OleDbDataReader reader = myCommand.ExecuteReader();

            while (reader.Read())
            {
                string name = (string)reader["Name"];
                double score = (double)reader["Score"];
                Console.WriteLine("{0} - score: {1}", name, score);
            }
            //}

            dbConn.Close();
            //Second way
            dbConn.Open();
            Console.WriteLine();
            Console.WriteLine("Second Way");
            Console.WriteLine("----------");
            DataTable dataSet = new DataTable();
            OleDbDataAdapter adapter = new OleDbDataAdapter("select * from [Sheet1$]", dbConn);
            adapter.Fill(dataSet);

            foreach (DataRow item in dataSet.Rows)
            {
                Console.WriteLine("{0}|{1}", item.ItemArray[0], item.ItemArray[1]);
            }
            dbConn.Close();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            date.CustomFormat = "dd/MM/yyyy";
            string chaine = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:/Users/dhib/Desktop/Professeur.accdb";
            OleDbConnection con = new OleDbConnection(chaine);
            OleDbCommand cmd = con.CreateCommand();

            cmd.CommandText = "Insert into module1(nom_module,coef,anne,semestre,login_enseignant) values ('" + txt_nv_module.Text + "','" + Convert.ToInt32(txt_coef.Text) + "','" + date.Text + "'," + Convert.ToInt32(txt_semestre.Text) + ",'" + login + "')";
          
           
            try
            {
                con.Open();
                cmd.ExecuteNonQuery();
                MessageBox.Show("Ajout Module Réussi");
                txt_nv_module.Text = "";
                txt_coef.Text = "";
                txt_semestre.Text = "";
                con.Close();
                
                new acceuil(login).Show();
                this.Hide();

            }
            catch (Exception ex)
            {
                MessageBox.Show("Erreur" + ex.Message);
                con.Close();
            }
        }

        private static int ExcelMaxRow = 999999999; //Convert.ToInt32(ConfigurationSettings.AppSettings["ExcelMaxRow"]);

        #endregion Fields

        #region Methods

        /// <summary>
        /// ����Excel  ��ȡExcel����   ������DataSet���ݼ���
        /// </summary>
        /// <param name="filepath">Excel������·��</param>
        /// <param name="tableName">Excel������</param>
        /// <returns></returns>
        public static System.Data.DataSet ExcelSqlConnection(string filepath, string tableName,string sheetName)
        {
            string errMsg = string.Empty;
            //string strCon = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filepath + ";Extended Properties='Excel 8.0;HDR=YES;IMEX=1'";
            ////OleDbConnection ExcelConn = new OleDbConnection(strCon);
            //try
            //{
            //    string strCom = string.Format("SELECT * FROM [Sheet1$]");
            //    DataSet ds = new DataSet();
            //    ds = DBdb2.RunDataSet(strCom, out errMsg);
            //    return ds;

            //}
            //catch
            //{
            //    return null;
            //}
            string strCon = "Provider=Microsoft.Ace.OleDb.12.0;" + "data source=" + filepath + ";Extended Properties='Excel 12.0; HDR=Yes; IMEX=1'";
            OleDbConnection ExcelConn = new OleDbConnection(strCon);
            try
            {
                string strCom = string.Format("SELECT * FROM ["+sheetName+"$]");
                ExcelConn.Open();
                OleDbDataAdapter myCommand = new OleDbDataAdapter(strCom, ExcelConn);
                DataSet ds = new DataSet();
                myCommand.Fill(ds, "[" + tableName + "$]");
                ExcelConn.Close();
                return ds;
            }
            catch
            {
                ExcelConn.Close();
                return null;
            }
        }

 private void FrmMain_Load(object sender, EventArgs e)
 {
     this.SetStyle(ControlStyles.OptimizedDoubleBuffer | ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint, true);
     string strPath = System.IO.Directory.GetCurrentDirectory() + BGimage;
     this.BackgroundImage = Image.FromFile(strPath);
     BtnStart.Image = Image.FromFile(System.IO.Directory.GetCurrentDirectory() + "\\images\\btn_start.png");
     //从数据库里读出所有可抽奖人员
     OleDbConnection odcConnection = new OleDbConnection(strConn);
     odcConnection.Open();
     OleDbCommand odCommand = odcConnection.CreateCommand();
     odCommand.CommandText = "select count(*) as result from seedlist";
     OleDbDataReader odrCount = odCommand.ExecuteReader();
     odrCount.Read();
     int allcount = Int32.Parse(odrCount[0].ToString());
     odrCount.Close();
     if (allcount < 9)
     {
         odcConnection.Close();
         MessageBox.Show("可供抽奖的人数不足,无法抽奖");
         this.Close();
     }
     else
     {
         //读取所有记录到数据
         SeedsList.Items.Clear();
         odCommand.CommandText = "select id,employee_dept,employee_name,employee_no from Seedlist where award_flag = '0' order by id asc";
         OleDbDataReader odrReader = odCommand.ExecuteReader();
         while (odrReader.Read())
         {
             SeedsList.Items.Add(odrReader[0].ToString() + ";" + odrReader[1].ToString() + ";" + odrReader[2].ToString() + ";" + odrReader[3].ToString());
         }
         odrReader.Close();
         odcConnection.Close();
     }           
 }

        public DataSet ExecuteReader(string q)
        {
            q = CleanQuery(q);

            Logger.CreateLog("ExecuteReaderQuery", q, null, EnumLogLevel.INFO);

            DataSet dataset = null;
            OleDbConnection oConn = new OleDbConnection(GetConnexionString());
            oConn.Open();

            try
            {
                OleDbCommand oCmd = new OleDbCommand(q, oConn);
                OleDbDataReader reader = oCmd.ExecuteReader();
                dataset = this.ConvertDataReaderToDataSet(reader);
            }
            catch (Exception ex)
            {
                oConn.Close();
                ex.HelpLink = q;
                throw ex;
            }
            oConn.Close();

            return dataset;
        }

 protected void Button2_Click(object sender, EventArgs e)
 {
     string s_add, r_add, message, heading,muid;
     s_add = Session["us_name"].ToString();
     r_add = TextBox1.Text;
     heading = TextBox3.Text;
     message = TextBox2.Text;
     rec_mail te = new rec_mail();
     conn = new OleDbConnection("Provider=MSDAORA;Data Source=orcl;Persist Security Info=True;Password=db_mail;User ID=db_mail");
     conn.Open();
     cmd = new OleDbCommand("insert into messages values(m_id.nextval,'" + heading + "','" + message + "'," + file_name + "',sysdate,sysdate,'Draft')", conn);
     dr = cmd.ExecuteReader();
     cmd = new OleDbCommand("insert into mail_exchange values('" + s_add + "',m_id.currval,sysdate,sysdate,'" + r_add + "')", conn);
     dr = cmd.ExecuteReader();
     cmd = new OleDbCommand("insert into draft values(m_id.currval)", conn);
     dr = cmd.ExecuteReader();
     dr.Close();
     cmd = new OleDbCommand("select m_id.currval from dual", conn);
     dr = cmd.ExecuteReader();
     dr.Read();
     muid = dr[0].ToString();
     dr.Close();
     conn.Close();
     Label1.Text = "Message Saved. Your message id is " + muid;
     Label1.Visible = true;
     dr.Close();
     conn.Close();
 }