With the QARv2 dll component you can perform full SQL Queries on any ADO Recordsets and return the results to your application.

No more complex filter and find routines or writing data to temporary tables.

No more expensive round trips to the Server to obtain a subset of data that already exists, saving on valuable Connection and Server resources.

Using the QARv2 dll component couldn't be easier, just add the ADO Recordsets that you wish to query, declare an alias for each Recordset for identification, decide on the Cursor and Lock Types, add your SQL (MS Access SQL Syntax) and execute the Query. Successful execution of the Query will return a disconnected ADO Recordset representing the Query results that will reflect the Cursor and Lock Types as defined. That's all there is to it.

When would you use the Component?

1. Filtering Data (Subsets of data)

Use the component to obtain a subset of the original data in an ADO Recordset.

Possible scenarios:

• You have already created an ADO Recordset containing the data required by your application and the initial population of the Recordset takes a considerable amount of time. Therefore
  you wish to utilize this data source in your application to avoid further round trips to the Database Server.
• The original ADO Recordset contains a subset of data from the Database that you wish to
  filter further in an application based on user selections or application requirements. The applications filtering functionality is such that conventional Database querying techniques would be extremely difficult to manage. i.e. the need for complex nested queries.

Advantages

• Limits the number of round trips to the Database Server by utilizing data already available
  to the client.
• Quicker than re-querying the Database. (Depending on size and complexity of Database.)
• Improved application development productivity, scalability, functionality and reliability.
• Removes the need for complex nested Queries.

2. Data Aggregation

Use the component to obtain an aggregated result of data that already exists in an ADO Recordset.

Advantages

• Limits the number of round trips to the Database Server by utilizing data already available
  to the client.
• Quicker than re-querying the Database. (Depending on size and complexity of Database.)
• A good solution when connections to the Database are not available or have limited access
  for security or concurrency reasons.

3. Joining Data

As long as the data source can be represented in an ADO Recordset you can use it to perform a Join.

• Join data from different Databases i.e. SQL Server and Oracle.
• Join data from other non-Database sources i.e. Text and application derived data.

There maybe situations when you need to Join data from different sources when conventional Database methods are not possible.

Possible scenarios

• No database connection i.e. disconnected data source.
• External data not contained in a Database i.e. Text file, or other data obtained from outside
  the local business environment.

4. Application with no Database

Use the component to provide SQL querying capabilities to an application without a Database.

Possible scenario:

• Simple client application that doesn't warrant a complicated Database i.e. (uses a saved ADO Recordset as a data store), however the application still has a requirement to provide the user/developer with querying capabilities that are beyond the functionality offered by the ADO Recordset i.e. Sort, Filter and Find.

Advantages

• Offers are flexible solution to providing querying capabilities on saved ADO Recordsets.
• No need to include a Database with the application to provide SQL querying capabilities.

5. Application derived data

Use the component in an application that uses application derived data or a mixture of database
and application derived data that requires querying capabilities to aid in the construction of ADO Recordsets consumed by the application.

Advantages:

• Reduction in the complexity of code normally required to manipulate application derived data.
• Improved application development productivity, scalability, functionality and reliability.

Compatibility