ADO.NET Objects – Data Providers Dr. Ron Eaglin. Requirements Visual Studio 2005 Microsoft SQL Server 2000 or 2005 –Adventure Works Database Installed.
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ADO.NET Objects – Data Providers
Dr. Ron Eaglin
Requirements
• Visual Studio 2005
• Microsoft SQL Server 2000 or 2005– Adventure Works Database Installed– Database available on local machine
Agenda
• Working with the Database Connection Object– ConnectionString property– Visual Creation of Connection– Code Creation of Connection
– Runtime Connections
Database ConnectionsCreate a new project
Windows application
Name project:AdventureWorksDemo1
Using Toolbox
• Right click on the data icon in the toolbox
• Select “Choose items …”
• This will bring up a dialog allowing you to select all items displayed from the list of available tools.
Data “items”Select SQLConnection fromList of available tools
The SQLConection objectWill now be in your Toolbox
Adding SQLConnection to FormDrag and dropSQLConnectionObject ontoForm.
SQL Connection ObjectSelect the SQLConnection object in the form and look at the Properties dialog box. Select the ConnectionString propertyAnd select <New Connection>
Add Connection
Select your server
Select AdventureWorks database
Test the connection
Add Connection
• ConnectionString property will fill with the text that allows the connection.
• ConnectionString has form
Keyword=value;keyword=value;keyword=value
Example:
Data Source=WHITEWATER;Initial Catalog=AdventureWorks;Integrated Security=True
Adding Connection String with Code Add button to form and
Change text of button
Double click button for Code window
Button Code windowEnter code here
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
' Create a new connection object of type SQLConnection Dim RuntimeConnection As New Data.SqlClient.SqlConnection ' Set the connection string RuntimeConnection.ConnectionString = "Data Source=WHITEWATER;Initial Catalog=AdventureWorks;Integrated Security=True"
Try RuntimeConnection.Open() MsgBox("Connection with connection string " + RuntimeConnection.ConnectionString + " opened successfully", MsgBoxStyle.Information) Catch ex As Exception MsgBox("Connection with connection string " + RuntimeConnection.ConnectionString + " failed to open", MsgBoxStyle.Information) End Try
RuntimeConnection.Close()
End Sub
Test Application
Add code to test SQLConnection1 Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click Try SqlConnection1.Open() MsgBox("Connection with connection string " + SqlConnection1.ConnectionString + " opened successfully", MsgBoxStyle.Information) Catch ex As Exception MsgBox("Connection with connection string " + SqlConnection1.ConnectionString + " failed to open", MsgBoxStyle.Information) End Try
SqlConnection1.Close() End Sub
Test SQLConnection1
SQLConnection Properties
• ConnectionString
• ConnectionTimeout
• Database
• DataSource
• ServerVersion
• State
Other types of Connections
• SQLConnection is specific to SQl Server only
• ODBCConnection – any ODBC database
• OLEDBConnection – Any OLE DB datasource
• OracleConnection
Agenda
• Creating and using a DataCommand object
• Issuing Database commands using the DataCommand object.
DataCommand object
• DataCommand is a simple ADO.NET wrapper for a SQL Statement.
• Using DataCommand from design and from run-time.
Design Window SQLCommand
• If SQLCommand is not in your toolbox, right click and add it to your toolbox using the Choose Items…
• Drag and drop the SQLCommand on to your form.
SQLCommand addedSQLCommand object inform
SQLCommand
• Properties of the SQLCommand– Connection– CommandType
• Text• StoredProcedure• TableDirect
– Parameters
SQLCommand1 Properties
• Set Connection = SQLConnection1
• Set CommandType = Text
• Click on … dialog on CommandText Property
Clicking on boxWill bring up queryBuilder.
Once the query is built – it is possible to use the previewData link in the properties window.
Runtime SQLCommand
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click Dim rtSQLCommand As New Data.SqlClient.SqlCommand
rtSQLCommand.Connection = SqlConnection1rtSQLCommand.CommandType = CommandType.TextrtSQLCommand.CommandText = "SELECT Person.Address.* FROM Person.Address"
End Sub
SQLCommand
• Note that running the code to create the runtime SQLCommand – does not actually do anything.
• We must execute the Command and also have a place for the results.
DataReader Object
• A DataReader is a lightweight object meant to hold the results of a SQLCommand
• DataReaders can be treated as a cursor to go through the DB values.
DataReader
SqlConnection1.Open() Dim rtDataReader1 As Data.SqlClient.SqlDataReader rtDataReader1 = rtSQLCommand.ExecuteReader
If rtDataReader1.HasRows = True Then MsgBox("The reader has found rows", MsgBoxStyle.Information) End IfSqlConnection1.Close()
Add this code to the previous code
Binding the Data ReaderAdd ListboxTo Form
Add code
While rtDataReader1.Read ListBox1.Items.Add(rtDataReader1.GetValue(1)) End While
Add code before closing the connection, after executing the reader.
Results of Code
Data from first field of DB Query is added to the list.
DataReader Methods
• Open code window
• Put cursor on the code
Dim rtDataReader1 As Data.SqlClient.SqlDataReader
Hit F1
Put cursor here
Help on DataReaderCode examples of using Data Reader
More code
Review
• Working with Database Connection
• Creating code to use database
• Using Command Objects
• Using the Data Reader Object
• Displaying Database Results
• Getting More Information on Objects
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