ADO.NET -database connection
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The document discusses ADO.NET and how it provides disconnected data access through the use of datasets, data adapters, and data providers. It covers the core ADO.NET objects like connection, command, data reader, and data adapter. It provides examples of loading data from databases into datasets using data adapters and binding datasets to controls for display and editing. The .NET framework supports multiple data providers for different database systems like SQL Server, Oracle, OLE DB, and ODBC.
ADO.NET -database connection
- 2. ADO.NET • ADO.NET .NET • ADO => ActiveX Data Object .NET
- 3. ADO NET Architecture • NET Framework data providers • The DataSet
- 4. windows Data Sources Windows Data sources (data source) - - IDE , (bind)
- 5. Data Provider • Query • Object DataSet • VS2005 – – – – SQL Server Data Provider OLEDB Data Provider Oracle Data Provider ODBC Data Provider MS SQL Server MS Access V.7
- 6. Data Provider • Data Provider – Connection – Command Query SQL – DataAdapter fill DataSet – DataReader result set read-only forward-only /
- 7. NET Framework Data Providers NET Framework data provider Description NET Framework Data Provider for SQL Server Provides data access for Microsoft SQL Server version 7.0 or later Uses the System.Data.SqlClient namespace NET Framework Data Provider for OLE DB For data sources exposed using OLE DB Uses the System.Data.OleDb namespace NET Framework Data Provider for ODBC For data sources exposed using ODBC Uses the System.Data.Odbc namespace 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, and uses the System.Data.OracleClient namespace
- 8. Core Objects of NET Framework Data Providers Object Description Connection Establishes a connection to a specific data source The base class for all Connection objects is the DbConnection class Command Executes a command against a data source Exposes Parameters and can execute within the scope of a Transaction from a Connection. The base class for all Command objects is the DbCommand class DataReader Reads a forward-only, read-only stream of data from a data source The base class for all DataReader objects is the DbDataReader class DataAdapter Populates a DataSet and resolves updates with the data source The base class for all DataAdapter objects is the DbDataAdapter class
- 9. - The NET Framework Data Provider for SQL Server Imports Provider Imports System Data SqlClient - The .NET Framework Data Provider for OLE DB Imports Provider Imports System Data OleDb Driver Provider SQLOLEDB Microsoft OLE DB Provider for SQL Server MSDAORA Microsoft OLE DB Provider for Oracle Microsoft Jet OLEDB 4.0 OLE DB Provider for Microsoft Jet
- 10. - The NET Framework Data Provider for ODBC Imports Provider Imports System Data Odbc Driver SQL Server Microsoft ODBC for Oracle Microsoft Access Driver mdb - The NET Framework Data Provider for Oracle Imports Provider Imports System.Data Imports System.Data.OracleClient
- 11. Choosing a NET Framework Data Provider Provider Notes NET Framework Data Provider for SQL Server Recommended for middle-tier applications using Microsoft SQL Server 7.0 or later Recommended for single-tier applications using Microsoft Database Engine MSDE or SQL Server 7.0 or later Recommended over use of the OLE DB Provider for SQL Server SQLOLEDB with the NET Framework Data Provider for OLE DB For SQL Server 6.5 and earlier, you must use the OLE DB Provider for SQL Server with the NET Framework Data Provider for OLE DB NET Framework Data Provider for OLE DB Recommended for middle-tier applications using SQL Server 6.5 or earlier For SQL Server 7.0 or later, the NET Framework Data Provider for SQL Server is recommended Also recommended for single-tier applications using Microsoft Access databases Use of an Access database for a middle-tier application is not recommended NET Framework Data Provider for ODBC Recommended for middle and single-tier applications using ODBC data sources NET Framework Data Provider for Oracle Recommended for middle and single-tier applications using Oracle data sources
- 12. 2. Data Set Designer Vs DataSet .Net Framework disconnected data access ( Data Table) ) DataSet ( DataSet
- 13. ADO NET DataSet
- 14. dataSet Data Table Customers Orders Table Adapter SME Table Adapter Customer Orders
- 15. DataSet • DataSet Disconnected data access • – DataTable
- 20. ADO NET Sample Application Option Explicit On Option Strict On Provider SqlClient Imports System Imports System Data Imports System Data SqlClient Public Class Program Public Shared Sub Main Dim connectionString As String GetConnectionString Dim queryString As String _ SELECT CategoryID, CategoryName FROM dbo Categories; Using connection As New SqlConnection connectionString Dim command As SqlCommand connection CreateCommand command CommandText queryString
- 21. Try connection Open Dim dataReader As SqlDataReader _ command ExecuteReader Do While dataReader Read Console WriteLine vbTab & {0} & vbTab & {1} , _ dataReader 0 , dataReader 1 Loop dataReader Close Catch ex As Exception Console WriteLine ex Message End Try End Using End Sub Private Shared Function GetConnectionString As String ' To avoid storing the connection string in your code, ' you can retrieve it from a configuration file Return Data Source local ;Initial Catalog Northwind; _ & Integrated Security SSPI; End Function End Class
- 22. ADO NET Sample Application Option Explicit On Option Strict On Provider Imports System Imports System Data Imports System Data OleDb Public Class Program Public Shared Sub Main Dim connectionString As String GetConnectionString Dim queryString As String _ SELECT CategoryID, CategoryName FROM Categories; Using connection As New OleDbConnection connectionString Dim command As OleDbCommand connection CreateCommand command CommandText queryString Try OleDb
- 23. Try connection Open Dim dataReader As OleDbDataReader _ command ExecuteReader Do While dataReader Read Console WriteLine vbTab & {0} & vbTab & {1} , _ dataReader 0 , dataReader 1 Loop dataReader Close Catch ex As Exception Console WriteLine ex Message End Try End Using End Sub Private Shared Function GetConnectionString As String ' To avoid storing the connection string in your code, ' you can retrieve it from a configuration file ' Assumes Northwind mdb is located in c Data folder Return Provider Microsoft Jet OLEDB 4.0;Data Source _ & c DataNorthwind mdb;User Id admin;Password ;
- 24. Just do it! • • OleDB Provider Northwind Ms Access Import Provider Imports System.Data.OleDB Dim objConn As New System.Data.OleDbConnection() objConn.ConnectionString = “Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:Northwind.mdb”
- 26. Command Sql Select, Update, Delete, Insert Dim objComm As New OleDb.OleDbCommand() Provider CommandText objComm.CommandText = “Select * from Employyes” objComm.ExecuteNonQury objComm.ExecuteScalar objComm.ExecuteReader
- 27. Command Sql Select, Update, Delete, Insert Dim objComm As New OleDb.OleDbCommand() Provider CommandText objComm.CommandText = “Select * from Employyes” objComm.ExecuteNonQury objComm.ExecuteScalar objComm.ExecuteReader
- 28. objComm.ExecuteReader Set dataReader Dim dr As OleDb.OleDbDataReader dr = objComm.ExcuteReader Item DataReader While dr.read() Dim myObj As object = dr.Item(3) Dim myOtherObj As object = dr.Item(“Customer”) End While
- 29. objComm.ExecuteReader Set dataReader Dim dr As OleDb.OleDbDataReader dr = objComm.ExcuteReader Item DataReader While dr.read() Dim myObj As object = dr.Item(3) Dim myOtherObj As object = dr.Item(“Customer”) End While
- 31. Dim strSQL As String = “Select CustomerID,CompanyName F Sub Dim objConn As New OleDbConnection(StrConn) Dim objComm As New OleDbCommand(strSQL,objConn) Dim dr As OleDbDataReader objConn.Open() dr = objComm.ExecuteReader() ListBox1.Items.Add(“ ” & ControlChars.Tab & “ Do while dr.Read() Dim strRecord As String = dr.Item(“CustomerID”).tostring( Item(“CompanyName”).Tostring() ListBox1.Items.Add(strRecord) Loop
- 32. DataReader
- 33. DataAdapter DataAdapter => Dim da As New OleDb.OleDbDataAdapter Method Fill DataSet => dataAdapter.Fill(dataSet,tab Dim objConn As New Data.OleDbConnection(“Provider=Microsoft.Jet.OL _ EDB.4.0;Data Source=C:Northwind.mdb”) Dim strSQL As String = “Select * from Employees” Dim da As New OleDb.OleDbDataAdapter Da.SelectCommand = New OleDb.OleDbCommand(strSQL,objConn) Dim ds As New DataSet da.Fill(ds,”Employees”) dataSet dataSet.Tables(table).rows(row).(field) textbox1.text = ds.Tables(“employees”).row(0).(“FirstName”) ds.Tables(“employees”).row(0).(“FirstName”
- 35. DataSet • DataSet Dim tb As DataTable = ds.Tables(“Employees”) Dim row As DataRow = tb.NewRow() row(“FirstName”) = “Chaimard” row(“LastName”) = “Kama” tb.Rows.Add(row)
- 36. DataSet Dim tb As DataTable = ds.Tables(“Employees”) For Each row As DataRow In tb.Rows if row(“FirstName”) = “Chaimard” Then row.(“FirstName”) = “Superman” end if Next
- 37. DataSet Dim tb As DataTable = ds.Tables(“Employees”) For Each row As DataRow In tb.Rows if row(“FirstName”) = “Chaimard” Then row.dalete() end if Next
- 38. Binding Data • Simple Binding Data textbox, Label • Complex Binding Data ListBox, ComboBox
- 39. Simple Binding Data : object.DataBindings.Add(propertyName,dataSource,dataMember) : textbox1.dataBindings.Add(“text”,ds.Tables(“emp”), “FirstName”) Listbox1.DataSource = ds.Tables(“emp”) Listbox1.DisplayMember = “FirstName” : Complex Binding Data With cboStudent ComboBox .datasource = ds.Tables(“Faculty”) .displaymember = “DescriptionThai” .ValueMember = “FacultyCode” .DataBindings.Add(“SelectValue”,objBS,“facultyCode”) End with 2. Student Student
- 40. : me.bindingContext(ds.Tables.(“emp”)).position = 0 : me.bindingContext(ds.Tables.(“emp”)).position += 1 : me.bindingContext(ds.Tables.(“emp”)).position =1 : me.bindingContext(ds.Tables.(“emp”)).position = me.bindingContext(ds.Tables.(“emp”)).count - 1 BindingSource Dim objBS As New BindingSource objBS.DataSource = ds.Tables(“emp”) (ds.Tables(“emp”) emp ) : objBS.MoveFirst : objBS.MoveNext