Deck 6: Updating Data

Question 1

The DROP TABLE command creates an empty table.

Answer 1

False

Question 2

MySQL does not support the COMMIT or ROLLBACK commands.

Answer 2

False

Question 3

MySQL allows you to reduce the size of a column.

Answer 3

True

Question 4

One of the nicest features of a relational DBMS, such as MySQL, is the ease with which you can change table structures.

Question 5

In some cases, you might need to change a table's structure in ways that are beyond the capabilities of your DBMS. When that happens, use the RESTRUCTURE command to redesign the table.

Question 6

You cannot change the characteristics of existing columns.

Question 7

You can use the ROLLBACK command to return the column length to its original state.

Question 8

If you decrease the size of a column, it is possible to lose some data currently in the column.

Question 9

If you specify NOT NULL for a column when you create a table, you are prohibited from changing a value in the column to null.

Question 10

In a transaction, it is acceptable if some steps fail.

Question 11

The command for changing a value to null is the same for changing any other value.

Question 12

You can cancel updates at any time during your current work session.

Question 13

You cannot use the INSERT command to update table data.

Question 14

When you update the data in a table, your updates are always permanent.

Question 15

The ROLLBACK command reverses changes made to a table's structure.

Question 16

You can use REMOVE ROW to remove a row from a table.

Question 17

The NULL value should be enclosed in single quotation marks.

Question 18

In some cases, when you update the data in a table, you can reverse (cancel)them at any time during your current work session.

Question 19

You cannot use a compound condition to update a row.

Question 20

MySQL does not allow you to change the size of DECIMAL columns.

Question 21

If you have verified that the update you made is correct, you can use the ____ command to make the update permanent.

A)UPDATE
B)ROLL
C)COMMIT
D)SAVE

Question 22

In order to use the COMMIT command in MySQL, you need to change the value for AUTOCOMMIT to ____.

A)0
B)1
C)YES
D)NO

Question 23

When necessary, include a WHERE clause into the UPDATE command to indicate the column on which the change is to take place.

Question 24

In MySQL, use the ____ data type for variable-length character columns.

A)TEXT
B)VARCHAR
C)VARIABLE
D)CHARLENGTH

Question 25

When you use the CREATE TABLE command with the word LIKE to create a new table from an existing table, the new table has the same data as the original table.

Question 26

A(n)____ can be viewed as a sequence of steps that accomplishes a single task.

A)procedure
B)transaction
C)program
D)method

Question 27

In order to use the ROLLBACK commands in MySQL, you need to change the value for ____ to 0.

A)AUTOROLL
B)AUTOCOMMIT
C)AUTOROLLBACK
D)ENABLE

Question 28

In MySQL, use the ____ command to show the revised structure of a table.

A)DESCRIBE COLUMNS
B)DISPLAY DATA
C)DISPLAY COLUMNS
D)SHOW COLUMNS

Question 29

There are table structure changes that are beyond the capabilities of MySQL.

Question 30

You must execute the SET AUTOCOMMIT = 0; command once at the beginning of a session and once at the end of the session if you want to use the COMMIT and ROLLBACK commands.

Question 31

It is possible to use calculations to update a value in a column.

Question 32

The command, CREATE TABLE AS LEVEL1_CUSTOMER FROM CUSTOMER; creates a table called LEVEL1_CUSTOMER that has the same structure as CUSTOMER.

Question 33

If you have not run the COMMIT command, executing the ____ command will reverse all updates made during the current work session.

A)UPDATE
B)REVERSE
C)ROLLBACK
D)ROLL

Question 34

To add a new column, use the ADD COLUMN clause of the ALTER TABLE command.

Question 35

To verify that the correct change was made to data in a table, use the DISPLAY command.

Question 36

The data stored in tables is subject to constant change.

Question 37

To permanently remove both a table and its data, you must issue both a DROP TABLE command and a DELETE command.

Question 38

You can increase the length of a column but you cannot decrease the length of a column.

Question 39

To delete data from the database, use the ____ command.

A)ROLLBACK
B)COMMIT
C)DELETE
D)UPDATE

Question 40

Updates become permanent automatically when you exit from MySQL.

Question 41

The UPDATE command contains the word ____________________, followed by the name of the column to be updated, an equals sign, and the new value.

Question 42

By placing a(n)____________________ command in an INSERT command, you can add the query results to a table.

Question 43

If you decide that you do not want to save the changes you have made during your current work session, you can reverse the changes by executing the ____________________ command.

Question 44

You can use the ____ clause of the ALTER TABLE command to change a column that currently rejects null values so that it will accept null values.

A)ADD
B)MODIFY
C)UPDATE
D)NULL

Question 45

If you specified ____________________ for the column when you created the table, then changing a value in a column to null is prohibited.

Question 46

To change a column that currently rejects null values so that it accepts null values, use the ____ clause of the ALTER TABLE command

A)ACCEPT NULLS
B)MODIFY
C)ADD NULLS
D)CREATE

Question 47

You use the ____________________ command to remove rows from a table.

Question 48

A(n)____________________ is a logical unit of work.

Question 49

What happens if you run a DELETE command that does not contain a WHERE clause?

A)The table will be deleted.
B)All rows will be deleted from the table.
C)All values would be replaced by nulls.
D)None of the above.

Question 50

To make the same update for all rows in a table, omit the ____ clause.

A)SET
B)UPDATE
C)WHERE
D)ALTER

Question 51

With SQL, you can change a table's structure by using the ____________________ command.

Question 52

Which of the following is a valid SQL command?

A)DROP TABLE LEVEL1_CUSTOMER;
B)DROP LEVEL1_CUSTOMER;
C)DELETE LEVEL1_CUSTOMER;
D)All of the above

Question 53

During your current work session you can save your changes immediately by executing the ____________________ command.

Question 54

You can use the ____ command to create a new table using data in an existing table.

A)CREATE TABLE
B)NEW TABLE
C)UPDATE
D)ALTER TABLE

Question 55

If you specified ____ for a column when you created a table, then changing a value in a column to null is prohibited.

A)NOT NULL
B)NULL
C)CHAR
D)NUMBER

Question 56

The ____ command is permanent.

A)SELECT
B)COMMIT
C)SAVE
D)UPDATE

Question 57

You can use the ____ command to delete an entire table and its data.

A)ROLLBACK
B)DELETE TABLE
C)DROP TABLE
D)DELETE

Question 58

Which of the following is a valid SQL command?

A)COMMIT TABLE;
B)COMMIT CHANGES;
C)COMMIT DB;
D)COMMIT;

Question 59

Which of the following commands executes a rollback?

A)ROLLBACK TABLE;
B)ROLLBACK;
C)ROLLBACK ALL;
D)ROLLBACK DB;

Question 60

In MySQL, use the ____ command to show the layout of a table.

A)SHOW TABLE
B)SHOW ROWS
C)SHOW COLUMNS
D)SHOW LAYOUT

Question 61

To add a new column, use the ____________________ clause of the ALTER TABLE command.

Question 62

You can delete a table that is no longer needed by using the ____________________ TABLE command.

Question 63

The ADD clause consists of the word ADD followed by the name of the ____________________ to be added, followed by the characteristics.

Question 64

In MySQL, use the ____________________ command to show the layout of a table.

Question 65

In a transaction, if any update cannot be completed, execute the ____________________ command and discontinue the updates for the current transaction.

Question 66

The format for the ALTER TABLE command is the words ALTER TABLE followed by the name of the ____________________ to be altered, followed by an appropriate clause.

Question 67

Before beginning the updates for a transaction, commit any previous updates by executing the ____________________ command.

Question 68

You can change the characteristics of existing columns by using the ____________________ clause of the ALTER TABLE command.

Question 69

To sort rows in a specific order, use the ____________________ clause with the desired sort key(s).

Question 70

Describe the format of the ALTER TABLE command to add a new column.

Question 71

The ROLLBACK command reverses changes made to the ____________________ only.

Question 72

In a transaction, if you can complete all updates successfully, execute the ____________________ command after completing the final update.

Question 73

Describe the format for the UPDATE command.

Question 74

How can you use the COMMIT and ROLLBACK commands to support transactions?

Question 75

The command CREATE TABLE LEVEL1_CUSTOMER ____________________ CUSTOMER; creates a new table from an existing table.