answers)
Relationship correct answers association between entities
Types of relationships: correct answers One-to-many: Each rep is associated with many
customers. Each customer is associated with a single rep
Database correct answers structure that can store information about different categories of
information and relationships between those categories
Database Management System (DBMS) correct answers program, or collection of programs,
through which users interact with a database; can create forms and reports
Advantages of database processing: correct answers Getting more information from the same
amount of data
Sharing data
Balancing conflicting requirements
Controlling redundancy
Facilitating consistency
Expanding security
Increasing productivity
Providing data independence
Disadvantages of database processing: correct answers Larger file size
Increased complexity
Greater impact of failure
More difficult recovery
Rules of a Relation correct answers Two-dimensional table in which:
Entries are unnormalized
Each column has a distinct name (attribute name)
, All values in a column are values of the same attribute
Order of columns is immaterial
Each row is distinct
Order of rows is immaterial
Attribute correct answers characteristic or property of an entity (field/column)
Primary Key correct answers column or collection of columns of a table (relation) that uniquely
identifies a given row in that table
Foreign key correct answers field(s) whose value is required to match the value of the primary
key for a second table
Relational database correct answers collection of relations or tables
Basic relational algebra operations: correct answers SELECT-retrieves certain rows from an
existing table (based on criteria) and saves them as a new table (includes WHERE)
PROJECT-causes only certain columns to be included in the new table (includes OVER)
JOIN-two tables being joined
Structure of an SQL query: correct answers SELECT-FROM-WHERE
Use of compound conditions in WHERE statements: correct answers connecting two or more
simple conditions using one or both (AND/OR)
Use of LIKE: correct answers include in the WHERE clause
WHERE Street LIKE "Oxford";
Wildcards: correct answers Access:
*-collection of characters
?-any individual character
Other:
%-any collection of characters
_-any individual character
Computed Fields correct answers field whose values you derive from existing fields (+,-,*,/)
Built-in Functions correct answers (aggregate functions) COUNT, SUM, AVG, MAX, MIN