Relational Implementation With SQL Flashcards
Schema Owner
Person who has authority and responsibility for granting access to tables columns and views in a database schema,
Schema Definition
Description of database to the DBMS.
Multiset
A set that may have duplicate entries.
Simple Query
A query involving only one database table.
SELECT clause
Identifies the columns desired in the query.
FROM clause
Lists the existing tables referenced by the query.
WHERE clause
Gives the condition for selecting rows from identified tables.
Comparison Operators
= , <>,<,>,<=,>=
Boolean Connectives
AND-OR-NOT
Wild Card Characters
Special symbols that stand for unspecified strings of characters.
Cartesian Product
Result of pairing each row in one table withe every row in another table.
Alias
Alternate name given to a relation.
Correlated Subquery
A subquery whose result depends on the row being examined by an outer query.
EXISTS operator
Evaluates to true if resulting set is not empty.
NOT EXISTS operator
Evaluates to ture if resulting set is empty.
Built-in function
Statistical function that operates on a set of rows
SUM-AVG-COUNT-MAX-MIN
Set function
Built-in function
DISTINCT
Operator that eliminates duplicate rows.
GROUP BY
Indicates that rows should be grouped on a common value of specified columns.
HAVING
Places conditions on groups.
Union Compatible
Two or more relations that have equivalent columns
as to number and domains.
UNION
Operation that creates the set union of two relations.
INTERSECT
The operation that creates the set intersection of two relations.
EXCEPT
An operation that creates the set difference of two relations.
Natural Join
Operation that connects relations when common columns have equal values.
Join USING
Operation that connects relations when designated common columns have equal values.
Join ON
Operation that connects relations when a condition holds.
INSERT
Operation that causes rows to be added to be a relation.
UPDATE
Operation that changes column values in rows.
DELETE
Operation that removes rows from a relation
Embedded SQL
A set of statements that allows SQL to be used with traditional programming languages.
Host Langauge
Language of programs in which SQL statements can be embedded.
Flag Statements
SQL statements embedded in an application program to signal the beginning or end of a set of SQL statements.
Cursor
Embedded SQL facility where the result of an SQL query is stored for subsequent processing.
OPEN cursor statement
Embedded SQL statement that causes the DBMS to process a cursors query and store its result in the cursor.
FETCH statement
A statement that retrieves a single row from an opened cursor.