C# programming with database Basic guideline

First step Install SQL Server 2008/2010 (Professional edition if possible) Install Visual Studio 2008/2010  you can begin to do!!!

sql-server-2008-step-by-step-guide.aspx

SQL Server After installation,

ADO.NET 7 Includes number of classes that can be used to retrieve, manipulate, and update data in databases Can work with databases in a disconnect manner Database table(s) can be retrieved to a temporary file To retrieve data first, you must connect to the database ADO.NET uses a feature called data providers to connect, execute commands, and retrieve results from a database

Data Providers 8 Microsoft SQL Server Applications using SQL Server 7.0 or later Oracle Applications using Oracle data sources Object Linking and Embedding Database (OLE DB) Applications that use Microsoft Access databases Open Database Connectivity (ODBC) Applications supported by earlier versions of Visual Studio

Data Providers ( continued ) 9 Classes are encapsulated into a different namespace by provider Four core classes make up each data provider namespace Connection Command DataReader or DataSet DataAdapter

10 Data Providers ( continued )

C# programming language Go to Settings.settings

C# programming language Create a new class to work with Database, for example DatabaseHelper class In this class, create the connection such as: // declare the class level connection variable SqlConnection conn; // init with the above connection string in the constructure of the class conn = new SqlConnection(global::DoAnTinHocProject.Properties.Settings.Default.DoAnConnectionString); conn.Open();

C# programming language public DataSet SelectData(string SQLCommand) { // hàm m ẫ u đ ể th ự c thi các câu l ệ nh select, tr ả v ề d ữ li ệ u đư ợ c ch ứ a trong dataset DataSet ds = new DataSet(); try { if (sqlconn.State != ConnectionState.Open) sqlconn.Open(); SqlCommand sqlComm = new SqlCommand(); SqlDataAdapter sqlAdp = new SqlDataAdapter(); sqlComm.Connection = sqlconn; sqlComm.CommandText = SQLCommand; sqlComm.CommandType = CommandType.Text; sqlAdp.SelectCommand = sqlComm; sqlComm.ExecuteNonQuery(); sqlAdp.Fill(ds); return ds; } catch (Exception) { return null; } }

C# programming language Public int ExecuteCommand(string SQLCommand) { // hàm m ẫ u th ự c thi các câu l ệ nh insert, update, delete) try { if (sqlconn.State != ConnectionState.Open) sqlconn.Open(); SqlCommand sqlComm = new SqlCommand(); sqlComm.Connection = sqlconn; sqlComm.CommandText = SQLCommand; sqlComm.CommandType = CommandType.Text; return sqlComm.ExecuteNonQuery(); } catch (Exception) { return -1; }

C# programming language The example of using the above functions - To display data, use the DataGridView Control

C# programming language //Load data on datagridview control, transfer the SELECT command into the function SelectData DatabaseHelper h = new DatabaseHelper(); dataGridView1.DataSource = h.SelectData("Select * from Workdays ").Tables[0];

C# programming language // To insert data, transfer the Insert statement to the function ExecuteCommand DatabaseHelper h = new DatabaseHelper(); h.ExecuteCommand(“Insert into Workdays (ID, Day) values (1, ‘Monday’)”); // Update, Delete is similar with this