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ADO.NET and SQL Server Tuc Goodwin 5/22/2017 1 Introduction This is the Ninth of 15 planned presentations Upcoming presentations: Date Title 6/11/05 Using ADO.NET 7/9/05 TBD (Tuc is on Vacation) 8/13/05 Deploying Applications 9/10/05 Comparisons C# VB.NET part 1 10/8/05 Comparisons C# VB.NET part 2 5/22/2017 2 This Month’s Objective: Our overall objective is to access a SQL Server Database… This Presentation explains how to use ADO.NET with a Windows Forms application to create, read, update, and delete records in Access and SQL Server databases.. 5/22/2017 3 Demonstration Code We will build a short demonstration application as we go through this lecture. All code samples can be downloaded from: http://groups.msn.com/NTPCUGDevToolsSIG And soon Beginning VB.NET SharePoint Site: http://69.41.237.216:879/BEGVBNET/default.aspx End With 5/22/2017 4 Agenda 5/22/2017 ADO.NET Objects Data Providers Data Connection Data Command Data Adapter DataReader DataSet Data Access Building Blocks 5 ADO.NET Objects 5/22/2017 6 Data Providers A data provider in the .NET Framework serves as a bridge between an application and a data source. A data provider is used to retrieve data from a data source and to reconcile changes to that data back to the data source. The following table lists the .NET Framework data providers that are included in the .NET Framework. .NET Framework data provider Description .NET Framework Data Provider for SQL Server For Microsoft® SQL Server™ version 7.0 or later. .NET Framework Data Provider for OLE DB For data sources exposed using OLE DB. .NET Framework Data Provider for ODBC For data sources exposed using ODBC. .NET Framework Data Provider for Oracle For Oracle data sources. The .NET Framework Data Provider for Oracle supports Oracle client software version 8.1.7 and later. 5/22/2017 7 Data Connection This object establishes a connection to a specific data source. Properties: ConnectionString Methods: Open() Close() Dim nwindConn As SqlConnection = _ New SqlConnection("Data Source=localhost;Integrated Security=SSPI;" & _ "Initial Catalog=northwind") nwindConn.Open() 5/22/2017 8 Data Command This object uses the connection to create a command object. Then the program can implement several “Execute” methods to perform the action which may return data in a variety of formats. Dim catCMD As SqlCommand = New SqlCommand("SELECT CategoryID, _ CategoryName FROM Categories", nwindConn) Dim myReader As SqlDataReader = myCommand.ExecuteReader(CommandBehavior.CloseConnection) 5/22/2017 9 Execute Methods ExecuteReader – Sends the CommandText to the Connection and builds a SqlDataReader. ExecuteScalar – Executes the query, and returns the first column of the first row in the result set returned by the query. Extra columns or rows are ignored. ExecuteXMLReader - Sends the CommandText to the Connection and builds an XmlReader object. 5/22/2017 10 Data Adapter Represents a set of data commands and a database connection that are used to fill the DataSet and update a SQL Server database. This class cannot be inherited. Public Function SelectSqlSrvRows(dataSet As DataSet, connection As String, query As String) As DataSet Dim conn As New SqlConnection(connection) Dim adapter As New SqlDataAdapter() adapter.SelectCommand = new SqlCommand(query, conn) adapter.Fill(dataset) Return dataset End Function 5/22/2017 11 DataReader Provides a means of reading a forward-only stream of rows from a SQL Server database. Dim myReader As SqlDataReader = myCommand.ExecuteReader() If myReader.HasRows Then Do While myReader.Read() Console.WriteLine(vbTab & "{0}" & vbTab & "{1}", myReader.GetInt32(0), myReader.GetString(1)) Loop Else Console.WriteLine("No rows returned.") End If myReader.Close() 5/22/2017 12 DataSet Represents an in-memory cache of data. 5/22/2017 13 Data Access Building Blocks These are helper objects from Microsoft that encapsulates all the objects necessary to interact with the database. http://www.microsoft.com/downloads/details.aspx?FamilyId=F63 D1F0A-9877-4A7B-88EC-0426B48DF275&displaylang=en 5/22/2017 14 Summary We… started on ADO.NET and we wrote some more code… We’ll continue to build from here… 5/22/2017 15 Next Time… Deploying Applications (August) Comparisons VB.NET and C# (Part I) – Sept. Comparisons VB.NET and C# (Part II) – Oct. A new Series… 5/22/2017 16 Questions? 5/22/2017 17