and CORRECT Answers
1. These operations are relational algebra
collectively called
and are the theoreti-
cal foundation of the
SQL language. Since
the result of relation-
al operations is al-
ways a table, the re-
sult of an SQL query
is also a table.
2. Relational Algebra operation: Intersect
operation: Select
3. Relational Algebra
operation: Project
4. Relational Algebra
operation: Product
5. Relational Algebra
operation: Join
6. Relational Algebra
operation: Union
7. Relational Algebra
,selects a subset of rows of a table.
eliminates one or more columns of a
table.
lists all combinations of rows of two
tables.
*In the example, the product
operation selects all combinations
of Employee(table) and
Department (table) rows
combines two tables by comparing
related columns.
selects all rows of two tables.
selects rows common to two tables.
,8. Relational Algebra selects rows that appear in one table but not another.
operation: Differ-
ence
9. Relational Algebra changes a table name.
operation: Rename
10. Relational Algebra computes functions over multiple table rows, such as sum and count.
operation: Aggre-
gate
11. Relational rules are constraints
implemented as SQL
and
enforced by the data-
base system.
12. Name 3 relational Unique Primary Key
rules: Unique Column Names
No duplicate rows
13. Business rules are business policy
based on
and specific
to a particular data-
base.
14. The mathemati- Data Type
cal term "Do-
main" is synony-
mous with what
Database term?
, 15. The database term Column
"column" is synony-
mous with what File
System term?
16. What is SQL? a high-level computer language for storing, manipulating, and retrieving
data.
17. SQL syntax type: Lit- Explicit values that are string, numeric, or binary. Strings must be surround-
eral ed by single quotes or double quotes.Binary values are represented with
x'0' where the 0 is any hex value.
18. What is the definition Words with special meaning. (i.e. commands)
of an SQL Keyword?
19. SQL identifiers are tables, columns, etc.
objects from the
database like:
20. A statement intend- Comment
ed only for humans
and ignored by the
database when pars-
ing an SQL state-
ment., is considered
what?
21. 2