Solution to Question 20-1. In a relational database, the data is organized into tables, and the queries are defined by the relationships among the tables.
Solution to Question 20-2. A primary key is a column that contains values that are unique to the table in which it resides, which allows you to uniquely identify each row.
Solution to Question 20-3. A foreign key is a column in a table that is also the primary key in a different table. This allows you to identify the relationship among the tables.
Solution to Question 20-4. To retrieve the contents of the
Title column in the
Books table the appropriate query would be:
Select Title from Books
Solution to Question 20-5. To retrieve the contents of the
Author column where the value in the
Publisher column is "OReilly", the appropriate query would be:
Select Author from Books where Publisher = 'OReilly'
Solution to Question 20-6. You would want to use a join when you want to filter the information retrieved from one table based on the contents of a different table.
Solution to Question 20-7. The
DataSet object represents a subset of retrieved data, and can be used to view or manipulate the data.
Solution to Question 20-8. One good way to view the rows in a
DataTable object is to iterate over the
Rows collection with a
Solution to Question 20-9. The
DataAdapter class provides the bridge between your application and the database. The
DataAdapter can take a connection string ...