Q: What are advantages and disadvantages of Microsoft-provided data provider classes in ADO.NET
A: SQLServer.NET data provider is high-speed and robust, but requires SQL Server license purchased from Microsoft. OLE-DB.NET is universal for accessing other sources, like Oracle, DB2, Microsoft Access and Informix, but itââ.¬â.¢s a .NET layer on top of OLE layer, so not the fastest thing in the world. ODBC.NET is a deprecated layer provided for backward compatibility to ODBC engines.

Q: Whatââ.¬â.¢s the role of the DataReader class in ADO.NET connections
A: It returns a read-only dataset from the data source when the command is executed.

Q: What is the wildcard character in SQL
A: Letââ.¬â.¢s say you want to query database with LIKE for all employees whose name starts with La. The wildcard character is %, the proper query with LIKE would involve ââ.¬Ë.La%ââ.¬â.¢.

Q: What connections does Microsoft SQL Server support
A: Windows Authentication (via Active Directory) and SQL Server authentication (via Microsoft SQL Server username and passwords).

Q: Which one is trusted and which one is untrusted
A: Windows Authentication is trusted because the username and password are checked with the Active Directory, the SQL Server authentication is untrusted, since SQL Server is the only verifier participating in the transaction.

Q: Why would you use untrusted verificaion
A: Web Services might use it, as well as non-Windows applications.

Q: What does the parameter Initial Catalog define inside Connection String
A: The database name to connect to.

Q: Whatââ.¬â.¢s the data provider name to connect to Access database
A: Microsoft.Access.

Q: What does Dispose method do with the connection object
A: Deletes it from the memory.

Q: What is a pre-requisite for connection pooling
A: Multiple processes must agree that they will share the same connection, where every parameter is the same, including the security settings.

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