Notes - Lesson 11a

8/4/2019 Notes - Lesson 11a

1/16

Lesson 11:Developing Database

Applications

Lesson 11: Developing Database Applications 2

Objectives

What will you learn

What is ADO .Net

What are .Net Data Providers

How to connect to a database using a wizard

How to retrieve data from a database using a wizard


Introduction

ADO.NET provides access to data sources such asMicrosoft SQL Server, as well as data sources exposedthrough OLE DB

Applications can use ADO.NET to connect to these data

sources and retrieve, manipulate, and update data


2/16


Introduction

ADO .NET Namespaces

System.Data- The root namespace for the ADO .NETAPI

System.Data.OleDb- It contains classes that aredesigned to work with any data source

System.Data.SqlClient- Contains classes that areoptimized to work with Microsoft SQL Server databases


.NET Data Providers

.NET Framework Data Provider for SQL Server- forMicrosoft SQL Server version 7.0 or later

.NET Framework Data Provider for OLE DB- for datasources exposed using OLE DB

.NET Framework Data Provider for ODBC- for datasources exposed using ODBC

.NET Framework Data Provider for Oracle- for Oracledata sources, the .NET Framework Data Provider forOracle supports Oracle client software version 8.1.7 andlater


Connecting to Data Sources

Connection

Command

DataAdapter

DataReader

ADO .Net Architecture

DataSet

Data Consumers

.Net Data Provider

Database

Win Forms

Web Forms


3/16



Connection Class

In ADO.NET you use a Connection object to connect toa specific data source. For example, to connect toMicrosoft SQL Server version 7.0 or later, use theSqlConnection object of the .NET Framework DataProvider for SQL Server. Use the correspondingConnection object to connect to a data source.



The Data Source Configuration Wizard

Using the Data Source Configuration Wizard is an easyway of connecting applications to databases

When the wizard is finished, data will be available in theData Sources Window and is ready for dragging it ontoforms



Create a new project:

Select New then Project in the File menu

Select Windows Application and click OK


4/16



Create a connection to a database:

Select Add New Data Source on the Data menu



Select Database on the Choose a Data Source Typepage then select Next



Select New Connection to configure a new dataconnection if there are no connections yet


5/16



Check Yes if you want to save the connection stringthen click Next



Expand the Tables node and select the tables you wantto add to your Data Source and then click Finish



Add controls to the form:

Drag the table nodes you want from the Data Sourceswindow onto the form


6/16



Run the application:

Press F5 to run the application. The form should show

the data from the table you just dragged.



Using the Dataset Designer

After this lesson, you will be able to create tables basedon tables in a database without using a wizard

The Dataset Designer is a tool for creating and editingtyped datasets like TableAdapters, TableAdapterQueriesand Data Tables



Add a new dataset item to the project:

Click Add New Item on the Project menu

Click DataSet in the Templates box


7/16



The Dataset you added will be opened in the DatasetDesigner



Create a connection to thedatabase:

Click Server Explorer onthe View menu

Click the Connect toDatabase button in theServer Explorer

Add a new connection toyour database



Add tables in the dataset:

Drag tables from theServer Explorer and dropit in the dataset designer

You should see the ERDof the tables in thedataset designer


8/16



Creating Data- bound controls

Data bound controls are controls which can easily bindwith data components

Some examples of controls that can bind data areDataGrids, ListBoxesand ComboBoxes



Create a connection:

Create a new WindowsApplication Project

Connect it to a database

Expand the Tables nodeand select tables in theChoose Your DatabaseObjects dialog box andpress finish

You should now see thetable nodes in the DataSources Window that you

just selected



Create a Data- boundcontrol:

Drag a ComboBox, aListBox, or a

DataGridView from theToolbox Tab and drop itin the form. This will beyour data- bound control

In the Data SourcesWindow, drag the tablenode you want to viewand drop it in the control


9/16



Adding a navigator:

For you to be able to

navigate through theresults, drag aBindingNavigatorfromData in the Toolbox Taband drop it in the form

Change theBindingSourceproperty inthe Properties Window sothat your data binds toyour control




Press F5 to run theapplication. You shouldbe able to see the data inthe table you selected inyour data- bound control.Also, you should be ableto navigate through theresults by pressing theMove Next button



Creating a TableAdapter with multiple queries

TableAdaptersare objects that are used to simplify theinteraction of data objects to a database

It encapsulates the objects needed to communicate witha database and presents methods to access the data


10/16



Use the Dataset Designer:

Create a new project

and connect it to adatabase

Right-click the Datasetin the Data Sourceswindow

Choose Edit DataSetwith Designer



Add your queries:

Add a query to the TableAdapterby dragging a Queryfrom the DataSettab of the Toolbox onto the table youwant to query

The TableAdapterQuery Configuration Wizard shouldappear



Choose what Command type you want to use


11/16



Choose what type of query you want to use



You can add conditions in your query



You can change the name of your method


12/16



Execute the query:

Drag the table node you want from the Data Sources

window to the formTo call the method you created, you should have a codethat looks like this:

.(,[]);



Press F5 to run the application. The grid should be filledwith your query



Reading XML Data into a DataSet

XML Data can be read into a DataSet

The output can be a table consisting of all the attributes

of the given XML data and its values

In the following example, assume that the given XML filelooks like this:


13/16



Dominador

Bogart

4332533

10932 Bigge

Rd.

Quezon

City

94025

The is theTable Name

Attributes like and are theTable columns



Create the XML file that will be read into the dataset:

Choose Add New Item from the Project Menu

Select XML File and click Add

The XML file should load into the designer and should beready for edit

Type the previous code into the editor below the XMLdeclaration



Adding an XML file


14/16



The following codes will read data from the XML file tothe Dataset

myDataSet.ReadXml();dataGridView1.DataSource = myDataSet;dataGridView1.DataMember = "person";

Note that the DataSourceis the dataset and theDataMember is the table name



Creating Lookup Tables

A lookup table is used to display information from onetable based on the value of a foreign-key field in anothertableFor example, there are three tables, Publisher, Publishesand Product. The Publishes table consists of a pubIDwhich is a foreign key pointing to the Publisher and aprodID which is a foreign key pointing to the Product.Since the product name is in the Product table and thepublisher name is in the Publisher table, and you arepresenting data from the Publishes table, you need tocreate a lookup table which takes the pubID and prodIDso that you can output the product name and its

corresponding publisher.



Publisher, Publishes, Product Relationship


15/16



Create the Data Source:

Connect to SampleDB

databaseSelect the Publisher,Publishes, and Producttables, and then clickFinish

The DataSet should beadded to your projectand the three tablesshould appear in theData Sources window



Create data-bound controlson the form:

Expand the Productnode in the DataSources window

Change the drop type ofthe related Publishestable to Details byselecting Details fromthe control list on theOrders node



Expand the relatedPublishes node andchange the prodID andpubID columns drop

type to a combo box byselecting ComboBoxfrom the control list onthe prodID and pubIDnodes


16/16



Drag the related Publishes node from the DataSources window onto Form1



Create the lookup table functionality:

Drag the main Product node from the Data Sourceswindow directly onto the prodID combo box on Form1

Drag the main Publisher node from the Data Sourcewindow directly onto the pubID combo box on Form 1


Press F5

The output in the prodID combo box should display theProduct name and the output in the pubID combo boxshould display the Publisher name that corresponds tothe given Product

Notes - Lesson 11a

Documents

Transcript of Notes - Lesson 11a