A Complete Guide to Microsoft ActiveX Data Objects Library Download and Installation
Introduction
In this article, you will learn about Microsoft ActiveX Data Objects (ADO), a collection of software components that provide a programmatic interface to access data sources from client applications. You will also learn how to use ADO in Visual Basic, how to download the ADO library, and what are some of the alternatives to ADO.
Benefits and drawbacks of ADO
ADO is a part of Microsoft Data Access Components (MDAC), a set of technologies that enable data access across different platforms and devices. ADO acts as a layer between programming languages and OLE DB, a low-level interface that supports various types of data stores, whether relational or non-relational. ADO allows you to write code that can work with any data source without knowing its specific implementation details.Some of the benefits of using ADO are:Ease of use: ADO has a simple and consistent object model that is easy to learn and use.
High speed: ADO is optimized for performance and can handle large amounts of data efficiently.
Low memory overhead: ADO uses minimal memory resources and can release them when not needed.
Small disk footprint: ADO has a small size and does not require additional components or drivers.
Flexibility: ADO supports various features for building client/server and web-based applications, such as remote data service, data shaping, records and streams, etc.
Some of the drawbacks of using ADO are:Limited support: ADO is no longer actively developed or updated by Microsoft, and may not be compatible with newer versions of Windows or other platforms.
Dependence on OLE DB: ADO relies on OLE DB providers to access data sources, which may vary in quality, functionality, and performance.
Obsolete technology: ADO has been superseded by newer and more advanced data access technologies, such as ADO.NET, which offer more features, security, and scalability.
How to use ADO in Visual Basic
To use ADO in Visual Basic, you need to reference the ADO libraries, create and manipulate ADO objects and collections, and perform data operations with ADO.
Referencing the ADO libraries
The first step to use ADO in Visual Basic is to add the ADO libraries to the list of references in your project. To do this, follow these steps:Open your Visual Basic project or create a new one.
From the Project menu, select References.
In the References dialog box, scroll down and check the boxes for the following libraries:Microsoft ActiveX Data Objects 2.8 Library: This is the main library that contains the ADO objects and collections.
Microsoft ActiveX Data Objects Recordset 2.8 Library: This is an optional library that contains additional methods and properties for the Recordset object.
Microsoft ActiveX Data Objects (Multi-dimensional) 2.8 Library: This is an optional library that supports data shaping and hierarchical recordsets.
Click OK to close the dialog box and save your project.
By referencing these libraries, you can use the ADO objects and collections in your code by prefixing them with the ADODB namespace. For example, to create a Connection object, you can write:Dim conn As ADODB.ConnectionSet conn = New ADODB.Connection
Creating ADO objects and collections
The next step to use ADO in Visual Basic is to create and use the main ADO objects and collections that enable you to access and manipulate data. Here is a brief overview of some of the most important ones:Connection: This object represents a connection to a data source, such as a database or a file. You can use it to open and close connections, execute commands and queries, and manage transactions.
Command: This object represents a command or a query that can be executed against a data source. You can use it to specify parameters, properties, and options for the command or query.
Recordset: This object represents a set of records that result from executing a command or a query. You can use it to navigate, filter, sort, edit, and update data.
Field: This object represents a field or a column in a recordset. You can use it to access or modify the value, name, type, size, and attributes of the field.
Property: This object represents a property or an attribute of an ADO object or collection. You can use it to get or set the value, name, type, and description of the property.
Error: This object represents an error that occurs during an ADO operation. You can use it to get information about the error, such as the number, message, source, description, help file, help context, etc.
Event: This object represents an event that occurs during an ADO operation. You can use it to handle events such as opening or closing connections or recordsets, executing commands or queries, fetching or updating data, etc.
To create an ADO object, you can use the New keyword or the CreateObject function. For example, to create a Connection object, you can write:Dim conn As ADODB.ConnectionSet conn = New ADODB.ConnectionorDim conn As ObjectSet conn = CreateObject("ADODB.Connection")To create an ADO collection, you can use the GetObject function or access it through a parent object. For example, to create a Recordset object, you can write:Dim rs As ADODB.RecordsetSet rs = GetObject("C:\Data\Customers.xls")orDim rs As ADODB.RecordsetSet rs = conn.Execute("SELECT * FROM Customers")
Performing data operations with ADO
The final step to use ADO in Visual Basic is to perform data operations with ADO, such as opening and closing connections, executing commands and queries, retrieving and updating data, handling errors and events, etc. Here are some examples of how to do that:To open a connection to a data source, you can use the Open method of the Connection object and pass the connection string as an argument. For example, to open a connection to a Microsoft Access database, you can write:conn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Data\Northwind.mdb"
To execute a command or a query against a data source, you can use the Execute method of the Connection or the Command object and pass the SQL statement as an argument. For example, to execute a query that returns all the customers from France, you can write:Set rs = conn.Execute("SELECT * FROM Customers WHERE Country = 'France'")
To retrieve data from a recordset, you can use the Fields collection of the Recordset object and access the field values by name or by index. For example, to display the customer name and city from the current record, you can write:MsgBox "Name: " & rs.Fields("CompanyName").Value & vbCrLf & "City: " & rs.Fields(4).Value
To update data in a recordset, you can use the Edit and Update methods of the Recordset object and assign new values to the fields. For example, to change the customer name and city of the current record, you can write:rs.Editrs.Fields("CompanyName").Value = "New Name"rs.Fields(4).Value = "New City"rs.Update
To handle errors that occur during an ADO operation, you can use the Errors collection of the Connection object and loop through each Error object to get information about it. For example, to display all the errors that occurred after opening a connection, you can write:If conn.Errors.Count > 0 Then For Each err In conn.Errors MsgBox "Error Number: " & err.Number & vbCrLf & "Error Message: " & err.Description NextEnd If
To handle events that occur during an ADO operation, you can use the WithEvents keyword to declare an ADO object variable and write event procedures for it. For example, to declare a Connection object variable with events and write a procedure for the ConnectComplete event, you can write:Dim WithEvents conn As ADODB.ConnectionPrivate Sub conn_ConnectComplete(ByVal pError As ADODB.Error, adStatus As ADODB.EventStatusEnum, ByVal pConnection As ADODB.Connection) MsgBox "Connection completed."End Sub
How to download the ADO library
To download the ADO library, you need to download and install the MDAC 2.8 SDK, which contains the ADO components and documentation.
Downloading MDAC 2.8 SDK
The MDAC 2.8 SDK is available for free from the official Microsoft website. You can download it from this link: https://www.microsoft.com/en-us/download/details.aspx?id =5793. The file size is about 6 MB and the file name is mdac28sdk.exe. The MDAC 2.8 SDK includes the following components:ADO 2.8: The latest version of ADO that supports data shaping, records and streams, remote data service, etc.
OLE DB 2.8: The latest version of OLE DB that supports various data providers, such as SQL Server, Oracle, Jet, etc.
ODBC 3.8: The latest version of ODBC that supports various data drivers, such as Access, Excel, Text, etc.
RDS 2.8: The latest version of Remote Data Service that allows web-based data access and manipulation.
ADOX 2.8: The latest version of ADO Extensions for Data Definition and Security that allows creating and modifying database objects and permissions.
JRO 2.8: The latest version of Jet and Replication Objects that allows compacting and repairing Jet databases and synchronizing replicated databases.
ADO MD 2.8: The latest version of ADO Multi-dimensional that supports data shaping and hierarchical recordsets.
Documentation: The complete reference and samples for all the MDAC components.
Installing MDAC 2.8 SDK
To install the MDAC 2.8 SDK on your Windows machine, follow these steps:Double-click the mdac28sdk.exe file that you downloaded and accept the license agreement.
Select a destination folder for the installation and click Next.
Wait for the installation to complete and click Finish.
Verify that the installation was successful by checking the following:The destination folder should contain a subfolder named MDAC28SDK with all the components and documentation files.
The Windows registry should have entries for all the components under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DataAccess.
The Windows system folder should have DLL files for all the components, such as msado28.tlb, msjro28.dll, msadox28.dll, etc.
Troubleshooting MDAC 2.8 SDK installation
If you encounter any problems during or after the installation of the MDAC 2.8 SDK, here are some possible solutions:If you get an error message saying that some files are missing or corrupted, try to download the mdac28sdk.exe file again and reinstall it.
If you get an error message saying that some files are in use or locked by another process, try to close all other applications and restart your computer before installing the MDAC 2.8 SDK.
If you get an error message saying that some files are not registered or cannot be found, try to register them manually using the regsvr32 command. For example, to register the ADO library, type:regsvr32 msado28.tlb
If you have trouble using ADO or any other component in Visual Basic or another programming language, make sure that you have referenced the correct libraries in your project and that you have used the proper syntax and conventions in your code.
If you have trouble accessing a specific data source or provider, make sure that you have installed and configured it properly and that you have specified the correct connection string and parameters in your code.
Alternatives to ADO
ADO is not the only data access technology available for accessing data sources from client applications. There are several alternatives to ADO that offer different features and suitability for different scenarios. Here are some of them:ADO.NET: This is the successor of ADO that is designed for .NET Framework applications. It supports disconnected data access, XML integration, web services, data binding, etc. It uses data providers such as SQL Server, Oracle, OLE DB, ODBC, etc., to access data sources.
JDBC: This is a Java-based technology that allows Java applications to access relational databases using SQL statements. It uses drivers such as JDBC-ODBC Bridge, JDBC-Net, JDBC-OCI, etc., to connect to data sources.
ODBC: This is a low-level interface that allows applications to access various types of data sources using SQL statements. It uses drivers such as Access, Excel, Text, SQL Server, Oracle, etc., to connect to data sources.
OLE DB: This is a low-level interface that allows applications to access various types of data sources, whether relational or non-relational, using a common set of commands and properties. It uses providers such as SQL Server, Oracle, Jet, etc., to connect to data sources.
Entity Framework: This is an object-relational mapping (ORM) framework that allows .NET Framework applications to work with data as objects and properties rather than tables and columns. It uses LINQ to Entities, a query language that integrates with Visual Basic and C#, to access data sources.
Conclusion
In this article, you have learned about Microsoft ActiveX Data Objects (ADO), a data access technology that allows you to access and manipulate data sources from client applications. You have also learned how to use ADO in Visual Basic, how to download the ADO library, and what are some of the alternatives to ADO.ADO is a simple and fast way to access data sources, but it is also an outdated and limited technology that may not be compatible with newer platforms and scenarios. If you want to use ADO in your projects, you should be aware of its benefits and drawbacks, and consider using other data access technologies that offer more features, security, and scalability.If you want to learn more about ADO and related topics, here are some resources that you can check out:https://docs.microsoft.com/en-us/sql/ado/guide/appendixes/microsoft-activex-data-objects-ado: This is the official documentation for ADO from Microsoft.
https://www.w3schools.com/asp/ado_intro.asp: This is a tutorial on how to use ADO in ASP web pages.
https://www.tutorialspoint.com/vb6/vb6_ado.htm: This is a tutorial on how to use ADO in Visual Basic 6.
https://www.youtube.com/watch?v=4Z9KEBexzcM: This is a video on how to use ADO in Visual Basic .NET.
FAQs
Here are some frequently asked questions about ADO and its library download:Q: What is the difference between ADO and DAO?A: DAO stands for Data Access Objects, another data access technology from Microsoft that predates ADO. DAO is designed for accessing Jet databases, such as Access and Excel, while ADO is designed for accessing any data source through OLE DB. DAO is faster and simpler than ADO for Jet databases, but ADO is more flexible and powerful for other data sources.
Q: How can I check the version of ADO installed on my machine?A: You can check the version of ADO installed on your machine by using the Version property of the Connection object. For example, you can write:Dim conn As ADODB.ConnectionSet conn = New ADODB.ConnectionMsgBox "ADO Version: " & conn.Version
Q: How can I update the ADO library on my machine?A: You can update the ADO library on your machine by downloading and installing the latest version of MDAC from the official Microsoft website. The latest version of MDAC is 2.8 SP1, which includes ADO 2.8 SP1. You can download it from this link: https://www.microsoft.com/en-us/download/details.aspx?id=5793.
Q: How can I use ADO in other programming languages besides Visual Basic?A: You can use ADO in other programming languages besides Visual Basic by using the appropriate syntax and conventions for those languages. For example, you can use ADO in C# by using the System.Data.OleDb namespace and the OleDbConnection, OleDbCommand, OleDbDataReader, etc., classes. For example, to open a connection to a SQL Server database in C#, you can write:using System.Data.OleDb;OleDbConnection conn = new OleDbConnection("Provider=SQLOLEDB;Data Source=ServerName;Initial Catalog=DatabaseName;User ID=UserName;Password=Password");conn.Open();
Q: How can I use ADO with Excel files?A: You can use ADO with Excel files by using the Microsoft.Jet.OLEDB.4.0 provider and specifying the Extended Properties parameter in the connection string. For example, to open a connection to an Excel file in Visual Basic , you can write:conn.Open "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Data\Book1.xls;Extended Properties=""Excel 8.0;HDR=Yes;IMEX=1"";"The Extended Properties parameter allows you to specify the Excel file format, whether the first row contains column names, and whether the data is mixed or not.
Microsoft Activex Data Objects Library Download
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