User FAQs

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1) What is ADO.NET ?
This provides a consistent way to access different types of data sources and different types of databases.

2) Can you describe the DataReader class in ADO.NET ?
The DataReader is a forward only approach to getting read-only data.
This will retain an open connection to the database while retrieving data.

3) Can you describe a DataSet in ADO.NET ?
The DataSet is a disconnected cache of data that allows you to create multiple tables and fill them with data from different sources.
A DataSet object is more inline with a VBA ADO recordset.
A DataSet can be used with no database and could be populated with data from an XML file or other source.
It also allows you to enforce relationships between the tables.
DataSets can be either Typed or UnTyped.
DataSets can be serialized.

4) What is the difference between the 'System.Data.SQLClient' namespace and the 'System.Data.OleDbClient' namespace ?
OleDbClient - This is a general data provider for targetting any OLE DB data source, including Access.
SQLClient - This is a specific data provider for targetting SQL Server databases.

5) Write the code to connect to the Northwind Access database using OleDbClient and execute a SQL statement.
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6) What is the pre-requisite for connection pooling ?
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7) LINQ Question

.FirstOrDefault