Introduction to ADO.Net, VB.Net Database Tools and Data Binding ISYS 512

Client/Server Structure a. Presentation – user interface Menus, forms, reports, etc b. Processing logic Business rules c. Database Client Database Server SQL queries Results

Database Processing Querying database Updating database: –Insertion, deletion, modification

Steps to Retrieve Data Establishes a connection to the database. Executes commands against the database. Store data results.

A Simplified View of ADO.Net Objects Ado.Net Data Provider Connection Adapter Command Reader Dataset Data Consumer WinForm WebForm

ADO.NET Objects Connection Object: Represent a connection to the database. Command Object: The command object allows us to execute a SQL statement or a stored procedure. DataReader: It is a read-only and forward-only pointer into a table to retrieve records. DataSet Object: A DataSet object can hold several tables and relationships between tables. DataAdapter: This the object used to pass data between the database and the dataset.

Data Providers ODBC Provider –Open Database Connectivity A driver manager Used for relational databases OLE DB Provider –OLE DB interfaces provide applications with uniform access to data stored in diverse information sources, or data stores. –Access SQL Server Provider Oracle Provider –Microsoft’s.NET data provider for Oracle –Connecting to Oracle, the Server name is: XE

Using ODBC Windows XP: Control Panel /Administrative Tools/DataSource(ODBC) Three types of data source names –User DSN: usable only by you and only on the machine currently using. –System DSN: Any one using the machine can use. –File DSN: Can be copied and used by other computers with the same driver installed. Demo: –Excel: Data/Import –Access: File/Get External Data/Import, then select ODBC data source

Connecting to Database Adding connection: –Tools/Connect to database Data Source –ODBC –OLD DB (Access) –SQL Server –Oracle, etc. Server Explorer –Data connections: Right click data connection Add Connection –Tables, Views Create new SQL Server Database

Adding Data Source Data/Add New Data Source –Database: Using the connections –Service –Object LINQ To SQL Server

Working with SQL Server Starting SQL Server: –Control Panel/Administrative Tools/Services/SQLServer SQL Server database file extension: mdf Default database folder: testSQL08.mdf –C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\testSQL08.mdf

Creating SQL Server Database From Server Explorer, right click data connection and choose: Create new SQL Server Database Server name: –LocalServerName\SQLExpress Add new table: Right click Tables and choose Add New Table Add rows: Right click the table name and choose Show table data. Note: After creating the database, you may create an ODBC DSN to connect to it.

How to create ADO.Net objects? Automatically generated when creating data bound form. –Form wizard Using Data Adapter Wizard Using code: –Example: –dim strConn as string ="Provider=Microsoft.Jet.OLEDB.4.0;Data Source = c:\sales2k.mdb" –dim objConn as new OledbConnection(strConn) –objConn.open()

Data Binding Connect a control or property to one or more data elements. Simple binding: Use simple binding to display a field value in controls that show Data Bindings in the property window, such as text box or label. Complex binding: Use complex binding to bind more than one field to controls such as DataGrid and list box. Use the control’s Data Source and Data Member to bind the data.

Creating Data Bound Form Creating a form with ADO.Net objects and data- bound controls to display and update information in a dataset. Demo: –Add data source: Data/Add New Data Source Data/Show Data Source –Click the dropdown list next to the table’s name: Datagrid view Details –Drag the table to form.

Items Added to the Form Connection Table Adapter: click smart tag –Add query –Preview data Dataset: –Edit in dataset designer Binding Source –Add query: Add a new tool strip. –Preview data Binding navigator Code view: Form load event

Generated Code Private Sub CUSTOMERBindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CUSTOMERBindingNavigatorSaveItem.Click Me.Validate() Me.CUSTOMERBindingSource.EndEdit() Me.CUSTOMERTableAdapter.Update(Me.SalesDBDataSet.CUSTOMER) End Sub Private Sub Form3_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 'TODO: This line of code loads data into the 'SalesDBDataSet.CUSTOMER' table. You can move, or remove it, as needed. Me.CUSTOMERTableAdapter.Fill(Me.SalesDBDataSet.CUSTOMER) End Sub

Other Data Form Demos DataGrid View Add /Modify/Delete records. Read only form: –Delete AddNew, Delete, Save buttons from navigator bar.

Hierarchical Forms Parent table/Child table –Add parent table and child table to Data Source –Drag the parent table and the child table to the form. Parent table uses detail view and child table uses dataGrid view –RightClick Dataset object to choose Edit in Dataset Designer –With the designer, right click the parent table and choose Add/Relation –Change dataGrid’s DataSource property to the relation.

Detail Form with Bound ListBox Example: Customer table form with CID listbox and displays selected customer information in textboxes. –Choose detail view for the customer table. –Click the dropdown list next to the CID field and click ListBox –Drag the Customer table to the form. –Bind the CID field to the BindingSource: Activate the Property window and click the listbox Set the DataSOurce property to BindingSource Set the Display Member property to CID

Creating A Database Application Without Programming Creating a database application to display information and update database. A main form with buttons to open data forms: –DisplayInfo –Enter New –Modify –Exit