Section 13
Evaluate
this statement:
Which statement about this TRUNCATE TABLE statement is true?
You can
produce the same results by issuing the 'DROP TABLE employee' statement.
You can
reverse this statement by issuing the ROLLBACK statement.
You can
issue this statement to retain the structure of the employees table. (*)
You can
produce the same results by issuing the 'DELETE employees' statement.
A column's data type can always
be changed from NUMBER to VARCHAR2 but not from VARCHAR2 to NUMBER, provided
the table is empty. True or False?
True
False
(*)
The data type of a column can
never be changed once it has been created. True or False?
True
False
(*)
Comments on tables and columns
can be stored for documentation by:
Using
an UPDATE statement on the USER_COMMENTS table
Embedding
/* comment */ within the definition of the table.
Using
the ALTER TABLE CREATE COMMENT syntax
Using
the COMMENT ON TABLE or COMMENT on COLUMN (*)
When you use ALTER TABLE to add
a column, the new column:
Becomes
the first column in the table
Becomes
the last column in the table (*)
Can be
placed by adding a GROUP BY clause
Will
not be created because you cannot add a column after the table is created
DCL, which is the acronym for Data Control Language, allows:
The
CONROL TRANSACTION statement can be used.
A
Database Administrator the ability to grant privileges to users. (*)
The
ALTER command to be used.
The
TRUNCATE command to be used.
Examine this CREATE TABLE
statement:
CREATE TABLE emp_load
(employee_number CHAR(5),
employee_dob CHAR(20),
employee_last_name CHAR(20),
employee_first_name CHAR(15),
employee_middle_name CHAR(15),
employee_hire_date DATE)
ORGANIZATION EXTERNAL
(TYPE ORACLE_LOADER
DEFAULT DIRECTORY def_dir1
ACCESS PARAMETERS
(RECORDS DELIMITED BY NEWLINE
FIELDS (employee_number CHAR(2),
employee_dob
CHAR(20),
employee_last_name CHAR(18),
employee_first_name CHAR(11),
employee_middle_name CHAR(11),
employee_hire_date CHAR(10) date_format DATE mask
"mm/dd/yyyy"))
LOCATION ('info.dat'));
What kind of table is created here?
An
external table with the data stored in a file outside the database. (*)
A View.
An
external table with the data stored in a file inside the database.
None.
This is in invalid statement.
Given this employee table:
(employee_id NUMBER(10) NOT NULL,
first_name VARCHAR2(25) NOT NULL,
last_name VARCHAR2(30) NOT NULL,
hire_date DATE DEFAULT sysdate)
What will be the result in the hire_date column following
this insert statement:
INSERT INTO employees VALUES (10, 'Natacha', 'Hansen',
DEFAULT);
The
character string SYSDATE.
Statement
will work and the hire_date column will have the value of the date when the
statement was run. (*)
Statement
will fail, as you must list the columns into which you are inserting.
The
column for hire_date will be null.
CREATE TABLE student_table
(id NUMBER(6),
lname
VARCHAR(20),
fname
VARCHAR(20),
lunch_num
NUMBER(4));
Which of the following statements best describes the above
SQL statement:
Creates
a table named student_table with four columns: id, lname, fname, lunch_num (*)
Creates
a table named student with four columns: id, lname, fname, lunch_num
Creates
a table named student_table with four columns: lname, fname, lunch, num
Creates
a table named student_table with four columns: lname, fname, lunch, num
You want to create a table named
TRAVEL that is a child of the EMPLOYEES table. Which of the following
statements should you issue?
CREATE
TABLE travel
(destination_id number primary key, departure_date date,
return_date date, t.emp_id = e.emp_id);
CREATE
TABLE travel
(destination_id number primary key, departure_date date,
return_date date, JOIN emp_id number(10) ON employees (emp_id));
CREATE
TABLE travel
(destination_id number primary key, departure_date date,
return_date date, emp_id number(10) REFERENCES employees (emp_id));
(*)
CREATE
TABLE travel
(destination_id primary key, departure_date date,
return_date date, emp_id REFERENCES employees (emp_id));
Which
of the following are valid Oracle datatypes?
DATE,
BLOB, LOB, VARCHAR2
SYSDATE,
TIMESTAMP, DATE, LOCAL TIME ZONE
DATE,
TIMESTAMP WITH LOCAL TIME ZONE, BLOB (*)
TIMESTAMP,
LOB, VARCHAR2, NUMBER
Evaluate this CREATE TABLE
statement:
CREATE TABLE sales
( sales_id NUMBER(9),
customer_id NUMBER(9),
employee_id NUMBER(9),
description VARCHAR2(30),
sale_date TIMESTAMP WITH LOCAL TIME ZONE DEFAULT SYSDATE,
sale_amount NUMBER(7,2));
Which business requirement will this statement accomplish?
Description
values can range from 0 to 30 characters so the column should be fixed in
length.
All
employee identification values are only 6 digits so the column should be
variable in length.
Today's
date should be used if no value is provided for the sale date. (*)
Sales
identification values could be either numbers or characters, or a combination
of both.
Which statement about data types
is true?
The
CHAR data type should be defined with a size that is not too large for the data
it contains (or could contain) to save space in the database. (*)
The
BFILE data type stores character data up to four gigabytes in the database.
The
TIMESTAMP data type is a character data type.
The
VARCHAR2 data type should be used for fixed-length character data.
You need to store the HIRE_DATE
value with a time zone displacement value and allow data to be returned in the
user's local session time zone. Which data type should you use?
TIMESTAMP
WITH LOCAL TIME ZONE (*)
TIMESTAMP
WITH TIME ZONE
DATETIME
TIMESTAMP
The ELEMENTS column is defined
as:
NUMBER(6,4)
How many digits to the right of the decimal point are allowed
for the ELEMENTS column?
Four
(*)
Zero
Two
Six
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