Database Programming (using ADO)

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Database Programming (using ADO)

• Universal Data Access
• Microsoft strategy for providing access to
  information across the enterprise.
• UDA provides high-performance access to a variety
  of relational and non-relational information
  sources
• Text files, Spreadsheets, Relational Databases,
  Email
• Easy-to-use programming interface that is tool
  and language independent.
• Enables you to integrate diverse data sources,
  create easy-to-maintain solutions, and use your
  choice of best-of-breed tools, applications, and
  platform services

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UDA

• does not require expensive and time-consuming
  movement of data into a single data store,
• nor does it require commitment to a single
  vendors products
• based on open industry specifications with broad
  industry support, and works with all major
  established database platforms

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Microsoft Data Access Components

• the key technologies that enable UDA
• Data-driven client/server applications deployed
  over the Web or a LAN can use these components to
  easily integrate information from a variety of
  sources, both relational (SQL) and non-relational
• These components include ActiveX Data Objects
  (ADO), OLE DB, and Open Database Connectivity
  (ODBC)

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ActiveX Data Objects (ADO)

• The strategic application programming interface
  (API) to data and information.
• ADO provides consistent, high-performance access
  to data and supports a variety of development
  needs, including the creation of front-end
  database clients and middle-tier business objects
  that use applications, tools, languages, or
  Internet browsers.
• ADO is designed to be the one data interface
  needed for single and multi-tier client/server
  and Web-based data-driven solution development

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ActiveX Data Objects (ADO)

• ADO provides an easy-to-use interface to OLE DB,
  which provides the underlying access to data.
• ADO implements a minimal number of layers between
  the front end and data sourceall to provide a
  lightweight, high-performance interface
• ADO uses the Component Object Model (COM)
  automation interface - a language-neutral way of
  implementing objects that can be used in
  environments different from the one they were
  created in, even across machine boundaries
• VB.NET uses XML-based SOAP messaging instead of
  COM

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OLE DB

• The Microsoft strategic system-level programming
  interface to data across the organisation
• Standardized interface that allows programmers to
  use a standard set of programming tools to refer
  to data from any source
• OLE DB is designed for relational and
  non-relational information sources, including
  mainframe and hierarchical databases e-mail and
  file system stores text, graphical, and
  geographical data custom business objects, etc.

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OLE DB

• OLE DB defines a collection of COM interfaces
  that encapsulate various database management
  system services.
• These interfaces enable the creation of software
  components that implement such services.
• OLE DB components consist of data providers,
  which contain and expose data data consumers,
  which use data and service components, which
  process and transport data (such as query
  processors and cursor engines).

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Database Programming (using ADO)

• ActiveX Data Objects (ADO 2.0)
• Enables your client applications to access and
  manipulate data in a database server through
  any OLE DB provider
• Benefits are ease of use, high speed, low memory
  overhead

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How to Reference ADO 2.0 in Visual Basic

• To gain access to the ADO 2.0 objects in Visual
  Basic, set a reference to the appropriate ADO
  type library
• There are two ADO type libraries. One is called
  ADODB and is contained in MSADO15.DLL
• It appears in the References dialog box
  (available from the Project menu) as "Microsoft
  ActiveX Data Objects 2.0 Library
• The other is called ADOR and is contained in
  MSADOR15.DLL
• It appears in the References dialog as "Microsoft
  ActiveX Data Objects Recordset 2.0 Library"

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Database Programming (using ADO)

• The first type library (ADODB) is the larger and
  more feature-rich of the two
• It contains the main ADO objects and is the one
  used in most circumstances
• The second is a "lightweight" subset of the ADODB
  type library that supports only recordsets

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Database Programming (using ADO)
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Connecting an ADO Data Control to a Database

• Place an ADO Data Control on the form
• Properties of the ADO Data Control that must be
  set
• ConnectionString specifies the database file
  that the data control will communicate with
• RecordSource specifies the table that will be
  accessed

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Database Programming (using ADO)

• ActiveX Data Objects (ADO)

This is the ADO control added to the toolbox
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Database Programming (using ADO)
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Database Programming (using ADO)
Sample Data Model represented in Microsoft Access
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Database Programming (using ADO)

• Student Table

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Database Programming (using ADO)

• Create an instance of the ADO control on a form

The control is named adoStudent
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Database Programming (using ADO)

• Set the CONNECTIONSTRING property

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Database Programming (using ADO)
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Database Programming (using ADO)
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Database Programming (using ADO)
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Database Programming (using ADO)

• Set the RECORDSOURCE property

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Database Programming (using ADO)

• Set the RECORDSOURCE property

Select adCmdTable
Select a Table from the DB
The RECORDSOURCE property is now set to tblStudent
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Database Programming (using ADO)

• Add Data-Aware (Bound) controls to the form which
  are used to display the fields of data in the DB
  table (tblStudent)

Name txtID
Name txtName
Name txtAddress
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Database Programming (using ADO)

• Set the DATASOURCE and DATAFIELD properties of
  each of the Text Boxes
• DATASOURCE name of the ADO control (adoStudent)
• DATAFIELD name of the required field in the DB
  table (tblStudent)

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Database Programming (using ADO)

• The DATASORCE property

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Database Programming (using ADO)

• The DATAFIELD property

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Database Programming (using ADO)

• VB Front-End connected to a DB Back-End

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Data Control with two bound text boxes
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