Question 1

Which is the correct sequence of elements in a command to remove rows from a MySQL table?

Accepted Answer

The correct syntax to remove rows from a MySQL table is "DELETE FROM [table name] WHERE [condition];" which matches option B.

Question 2

Describe the format of the command used to add a new column to an existing MySQL table.

Accepted Answer

The answer of Describe the format of the command used...

Question 3

How does the procedure for adding rows to an existing MySQL table compare to that for populating a new table that has just been created?

Accepted Answer

The procedure for adding rows to an existing MySQL table is identical to that for populating a new table. In both cases, the INSERT INTO statement is used to add new rows.

Question 4

A MySQL command to change a value within a table to null _____.

Accepted Answer

The correct way to change a value within a table to null in MySQL involves using the UPDATE and SET commands along with a WHERE clause to specify which record(s) should be updated. This is the standard syntax for modifying existing data in a table.

Question 5

What do you need to know to complete the FIRST step in the process of creating a new table using data from an existing table, called CANDY, in MySQL?

Accepted Answer

To create a new table using data from an existing table, the first step involves knowing which columns from the existing table (in this case, CANDY) you want to include in the new table and understanding their characteristics (data types, constraints, etc.). This information is crucial for defining the structure of the new table.

Question 6

James has created a new MySQL table called FAVORITES and would like to populate it with data from the existing CANDY table. Which command can he use to add data for rows with a rating of seven or more?

Accepted Answer

Option B is correct because it uses the correct syntax for inserting data into a table (FAVORITES) from another table (CANDY) based on a condition (RATING > 7). This is achieved by combining the INSERT INTO and SELECT statements.

Question 7

Which command should Josephine use if she would like to add a new row to the BMI table in MySQL?

Accepted Answer

The correct syntax to add a new row to a table in MySQL is the INSERT INTO statement. The given command correctly specifies the table name (BMI) and the values to insert, matching the structure of the table.

Question 8

Patty begins entering an order into her DBMS using SQL, but soon discovers she cannot complete the order entry process owing to missing data. What should she do to follow best practices related to transactions?

Accepted Answer

Executing the ROLLBACK command is the best practice in this situation because it undoes any changes made during the transaction, ensuring the database remains consistent and no partial or incomplete data is saved.

Question 9

Barney learns that the phone number for his friend Lacey in his ADDRESS_BOOK table has been disconnected; thus, her number is now unknown to him. Which SQL statement should Barney use to update the table so as to reflect this unknown value?

Accepted Answer

To update a column value to NULL in SQL, the correct syntax is the UPDATE statement followed by the SET column name = NULL clause, where the condition to identify the correct row(s) to update is specified in the WHERE clause. Option D correctly follows this syntax to set Lacey's phone number to NULL.

Question 10

Which is the correct sequence of elements for a SQL command that will change a value in an existing table row?

Accepted Answer

The correct syntax for updating a value in an existing table row in SQL is: UPDATE [table name] SET [column name] = [new value]. This matches the sequence given in option D.

Question 11

Which of the following is a valid SQL command?

Accepted Answer

The correct SQL command to remove a table from the database is "DROP TABLE table_name;". Therefore, "DROP TABLE LEVEL1_CUSTOMER;" is a valid SQL command. The other options are not correctly formatted SQL commands for their intended actions.

Question 12

How do you change a value in a column to null?

Accepted Answer

The answer of How do you change a value in...

Question 13

Describe the format for the UPDATE command.

Accepted Answer

The answer of Describe the format for the UPDATE command....

Question 14

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

Accepted Answer

The answer of How can you use the COMMIT and...

Quiz 6: Updating Data