Modern Database Management - Self Check 06
The ________ clause sorts the final results rows of a query in ascending or descending order
ORDER BY
A database table is defined using the data definition language (DDL
T
The content of dynamic views is generated when they are referenced.
T
A ________ is a virtual table that is created dynamically upon request to a user.
dynamic view
The DROP TABLE command causes tables to be ________, ________, and ________ from the database.
removed, deleted, dropped
When using an expression in SQL, expressions inside the
Parenthesis
The content of dynamic views is generated when they are referenced
T
The comparison operators ________ and ________ are used to establish a range of values in SQL
<, >
The ________ command enables one to change table definitions.
ALTER TABLE
The ________ contains raw data
base table
Using aggregate functions will give a ________ answer
one-row
Every SELECT statement returns a ________ when it executes
result table
The ________ Boolean operator joins two or more conditions and returns results only when all conditions are true
AND
The ON UPDATE ________option allows changes to a parent table to pass onto a child table or tables.
CASCADE
SQL command defines a logical table from one or more tables
CREATE VIEW
A(n) ________ is a set of schemas put together that represent a database description
Catalog
Adding the keyword ________ to an SQL query will eliminate duplicate rows from the query result set
Distinct
A catalog is the structure that contains object descriptions created by a user.
F
A database is maintained and queried using the data mapping language (DML)
F
A referential integrity constraint specifies that the existence of an attribute in one table depends upon the existence of a foreign key in the same or another table
F
A single value returned from an SQL query that includes an aggregate function is called a vector aggregate
F
Count(*) tallies only those rows that contain a value, while Count counts all rows
F
DCL is used to update the database with new records
F
DCL is used to update the database with new records.
F
Implementation of a standard can never stifle creativity and innovation
F
Indexes generally slow down access speed in most RDMS
F
Materialized views are stored on disk and are never refreshed
F
SQL has been implemented only in the mainframe and midrange environments
F
SQL originated from a project called System-S
F
The CREATE SCHEMA DDL command is used to create a table
F
The DELETE TABLE DDL command is used to remove a table from the database
F
The DROP command deletes rows from a table individually or in groups.
F
The HAVING clause and the WHERE clause perform the same operation
F
The ORDER BY clause is the first statement processed in an SQL command
F
The comparison operators = and != are used to establish a range of values
F
The following query totals sales in state= 'MA' for each salesperson. Select salesperson_id, sum(sales) from salesperson group by salesperson_id having state = 'MA';
F
The following two SQL statements will produce different results. Select last_name, first_name from customer where state = 'MA' or state = 'NY' or state = 'NJ' or state = 'NH' or state = 'CT'; Select last_name, first_name from customer where state in ('MA','NY','NJ','NH','CT');
F
When creating a table, it is not important to consider foreign keyprimary key mates
F
When the select clause in the create view statement contains the keyword DISTINCT, the view can be used to update data
F
is a constraint that specifies that the value of an attribute in one relation depends upon the value of a primary key in the same or other relation
Referential integrity
The ________ SQL command lists the columns from base tables or views to be projected into the command result table
SELECT
In SQL the ________ and ________ clauses are required, while the ________ clause is needed when only certain rows are to be retrieved or multiple tables are to be joined.
SELECT; FROM; WHERE
A major benefit of SQL as a standard is reduced training costs
T
Adding the DISTINCT keyword to a query eliminates duplicates
T
Applications can be moved from one machine to another when each machine uses SQL
T
Expressions are mathematical
T
If multiple boolean operators are used in an SQL statement, NOT is evaluated first, then AND, then OR
T
In order to update data in SQL, one must inform the DBMS which relation, columns, and rows are involved
T
One of the original purposes of the SQL standard was to provide a vehicle for portability of database definition and application modules between conforming DBMSs
T
SQL is both an American and international standard for database access
T
Some DBMS can handle graphic data types, as well as text and numbers
T
The ALTER TABLE command is used to change a table definition
T
The FROM clause is the first statement processed in an SQL command
T
The ORDER BY clause sorts the final results rows in ascending or descending order
T
The SQL command used to populate tables is the INSERT command
T
The WHERE clause includes the conditions for row selection within a single table or view, and the conditions between tables or views for joining
T
The WHERE clause is always processed before the GROUP BY clause when both occur in a SELECT statement.
T
The asterisk (*) wildcard designator can be used to select all fields from a table, as well as in WHERE clauses when an exact match is not possible
T
The following query totals sales for each salesperson. Select salesperson_id, sum(sales) from salesperson group by salesperson_id;
T
The following two SQL statements will produce the same results. Select last_name, first_name from customer where credit_limit > 99 and credit_limit < 10001; Select last_name, first_name from customer where credit_limit between 100 and 10000;
T
When a GROUP BY clause is included in an SQL statement, only those columns with a single value for each group can be included'True
T
When creating tables, it's important to decide which columns will allow null values before the table is created
T
The HAVING clause acts as a secondary ________ clause
WHERE
The ________ is a set of commands used to define a database
data definition language
The ________ is a set of commands used to define a database
data manipulation language
Indexes are created in most RDBMS to provide rapid ________ and ________ access to base-table data
random; sequential
To update data in SQL we must inform the DBMS what ________, ________, and ________ are involved
relation, columns, rows
A DBMS that manages data as a collection of tables in which all data relationships are represented by common values in related tables is called a(n) ________ DBMS.
relational
The structure that contains descriptions of objects created by a user, such as base tables and views is called a(n) ________
schema
