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DatabaseDatabase Access API’s Access API’s

Aleksandar StanimirovićLeonid StoimenovAleksandar Milosavljević

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Exercise goalsExercise goals

Get familiar with connecting to different data sources through ADO

Get know the basic of ADO object modelGet familiar with using VB as rapid

application development toolGet familiar with using ADO in VB

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ADOADO

Stands for ActiveX Data Objects Part of Universal Data Access architecture ADO object hierarchy Programming with ADO

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Visual BasicVisual Basic integrated environment integrated environment

Object Object viewerviewerCodingCoding

windowwindow

FormFormdesignerdesigner

ToolboxToolboxPropertyPropertywindowwindow

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ADO support in VBADO support in VB

Programming with automated data binding tools

Programming with ADO objects in VB code

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Adding ADO support in VBAdding ADO support in VB

ADO support ADO support added by added by

defaultdefault

User must User must add ADO add ADO supportsupport

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Programming with automated Programming with automated data binding toolsdata binding tools

Data aware controlsADO Data ControlData Environment Designer

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Data aware controlsData aware controls

Almost all VB controls are data aware:

Four properties for binding with data source:

1. Data source

2. Data member

3. Data field

4. Data format

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ADO Data ControlADO Data Control

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Data Environment DesignerData Environment Designer

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Programming with ADO objects Programming with ADO objects in VBin VBSet cnNWind = New ADODB.ConnectionSet cnNWind = New ADODB.Connection

Set rsEmployees = New ADODB.RecordsetSet rsEmployees = New ADODB.Recordset

Dim sConnect As StringDim sConnect As String

sConnect = “Provider=Microsoft.Jet.OLEDB.sConnect = “Provider=Microsoft.Jet.OLEDB.44..00;Data Source= ;Data Source= NWind.mdb”NWind.mdb”

cnNWind.Open sConnectcnNWind.Open sConnect

rsEmployees.Open “Select * From Employees Order By rsEmployees.Open “Select * From Employees Order By LastName,FirstName”, cnNWindLastName,FirstName”, cnNWind

Do While Nor rsEmployees.EOFDo While Nor rsEmployees.EOF

Debug.Print rsEmployees!FirstName + rsEmployees!LastNameDebug.Print rsEmployees!FirstName + rsEmployees!LastName

LoopLoop

rsEmployees.ClosersEmployees.Close

cnNWind.ClosecnNWind.Close

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ExerciseExercise

1. Create Data project in VB2. Using existing form in project show data

from specified table in database Place ADO Data control on form Link ADO Data control with existing exercise

database on Oracle or MS SQL Server Place controls on form and link them with ADO

Data control

3. Add new form in project and show data based on previous exercise query.

Using Data environment create connection to existing database on Oracle or SQL Server

Create Command object that executes specified SQL query.

Place on database fields from Data environment. Add code that scroll database data.