Absolute Beginner’s Guide to Databases

Appendix C. Glossary

Aggregate Function

SQL aggregate functions such as Count(), Sum(), Avg(), Min(), and Max() provide the capability to summarize data when performing a query.

Alias

An alias is a name variation of a table in a SQL query. For example, the following query uses an alias name of c in place of the actual name of the customers table:

SELECT C.CompanyName, *
   FROM Customers c;

Attribute

• A field/column of a table.

• A property of a field such as a caption, data type, size, and so forth.

Boyce-Codd Normal Form (BCNF)

BCNF is an extension of the Third Normal Form. A table is in the Boyce-Codd Normal Form when the dependency of each data item in a table can be traced to a candidate key. To illustrate, consider the following structure: ...