Learning SQL on SQL Server 2005

Glossary of Terms

Aggregate Function

A function that returns a result based on values of some attributes in multiple rows.

Alias

A temporary intra-query substitute for a table name or column name.

Alphanumeric

A data type that will accept a combination of characters as well as numbers.

Anomaly

An undesirable consequence of a data modification.

Attribute

Column in a table.

Binary Intersection

An operation on two sets that generates unique values in common between two sets.

Binary Set Difference

An operation on two sets that generates values in one set less those contained in another.

Binary Union

An operation on two sets that generates all unique elements of both sets.

Byte

A storage unit consisting of 8 bits.

Candidate Key

A column (attribute, or group of columns) that identifies a unique row in a table. One of the candidate keys is chosen to be the primary key.

Cartesian Product

A binary operation resulting in the combination of all rows of one table with all rows of another table.

CHAR(size)

Data type that stores fixed-length character data, size characters long.

Columns

Vertical slices of a table. Columns are defined to be one data type.

Column Alias

A temporary column name within a query.

Comments

Nonexecutable words included in SQL queries for documentation.

Constant

An unvarying value used in a query.

Constraint

A restriction placed on a value in a database used to increase data integrity.

Correlated Subquery

A subquery in which the information in the subquery is referenced ...