A database most often contains one or more tables. Each table is identified by a name (e.g. "Customers" or "Orders"). Tables contain records (rows) with data.
Below is an example of a table called "Persons":
The table above contains three records (one for each person) and four columns (LastName, FirstName, Address, and City).
With SQL, we can query a database and have a result set returned.
A query like this:
SELECT LastName FROM Persons
Gives a result set like this:
Note: Some database systems require a semicolon at the end of the SQL statement. We don't use the semicolon in our tutorials.