Querying Information in a Database

CONTENTS Relational Database Systems Creating Database with SQL Server Reading Data with LINQ Requirements to Get Data From Database Step by Step Writing Data to on DataBase Summary Examples Questions

Relational Database Systems Oracle FoxPro IBM DB2 Linter Microsoft Access Microsoft SQLServer MySQL PostgreSQL SQLite

Creating Database with MySQL

Reading Data with LINQ

Requirements to Get Data From Database Step by Step Adding Namespace Creating Connection and Opening it Determine the SqlDataAdapter Reading Data Closing Connection

Adding Namespace System.Data.SqlClient (the.NET Framework Data Provider for SQL Server) System.Data.Odbc (the.NET Framework Data Provider for ODBC) System.Data.OracleClient (the.NET Framework Data Provider for Oracle) System.Data.OleDb (the.NET Framework Data Provider for OLE DB)

Connection The Connection Object is a part of ADO.NET Data Provider and it is a unique session with the Data Source The Connection Object is Handling the part of physical communication between the C# application and the Data Source Opening connection is like opening a folder

Connection SqlConnection conn = new SqlConnection(); Con.ConnectionString Con.Open();

SqlDataAdapter A data adapter is an object used to exchange data between a data source and a data set

SqlDataAdapter

Reading Data and Closing Connection DataGridView displays data from SQL databases. This tutorial shows how to display a specific table from a database and display it on a DataGridView. This is done with a DataAdapter DataGridView.DataSource = DataTable; Conn.Close(); //Important to close connection

Writing Data to on DataBase Use SqlCommand Use ExecuteNonQuery string Kmt = "INSERT INTO Customers (CustomerID,CompanyName,ContactName,City) VALUES ('" + textBox1.Text + "','" + textBox2.Text + "', …) "; SqlCommand komut = new SqlCommand(Kmt, baglanti); komut.ExecuteNonQuery();