-
What is the purpose of the GROUP_CONCAT() function in MySQL?
- A) To calculate the average value of a numeric column
- B) To concatenate values from multiple rows into a single string
- C) To find the maximum value of a column
- D) To count the number of rows in a table
Answer: B) To concatenate values from multiple rows into a single string
-
Which SQL command is used to revoke privileges from a user in MySQL?
- A) REVOKE
- B) DENY
- C) WITHDRAW
- D) REMOVE
Answer: A) REVOKE
-
What is the purpose of the LEFT JOIN in MySQL?
- A) To combine rows from two or more tables based on a related column
- B) To filter rows based on a specified condition
- C) To perform aggregate functions on grouped data
- D) To retrieve all records from the left table and matching records from the right table
Answer: D) To retrieve all records from the left table and matching records from the right table
-
Which SQL command is used to remove an index from a table in MySQL?
- A) DELETE INDEX
- B) DROP INDEX
- C) REMOVE INDEX
- D) ERASE INDEX
Answer: B) DROP INDEX
-
What is the purpose of the IS NULL operator in MySQL?
- A) To check if a value is not null
- B) To check if a value is null
- C) To filter rows based on a specified condition
- D) To specify the columns to retrieve in the result set
Answer: B) To check if a value is null
-
Which SQL function is used to round a numeric value to a specified number of decimal places in MySQL?
- A) ROUND()
- B) TRUNCATE()
- C) CEIL()
- D) FLOOR()
Answer: A) ROUND()
-
What is the purpose of the LIKE operator in conjunction with the % wildcard in MySQL?
- A) To match any single character
- B) To match any sequence of characters
- C) To match zero or more occurrences of a character
- D) To match one or more occurrences of a character
Answer: B) To match any sequence of characters
-
Which SQL command is used to rename an existing column in a table in MySQL?
- A) RENAME COLUMN
- B) MODIFY COLUMN
- C) CHANGE COLUMN
- D) ALTER COLUMN
Answer: C) CHANGE COLUMN
-
What is the purpose of the COALESCE() function in MySQL?
- A) To concatenate values from multiple rows into a single string
- B) To return the first non-null value in a list of expressions
- C) To calculate the average value of a numeric column
- D) To count the number of rows in a table
Answer: B) To return the first non-null value in a list of expressions
-
Which SQL command is used to create a new database in MySQL?
- A) CREATE DATABASE
- B) NEW DATABASE
- C) ADD DATABASE
- D) MAKE DATABASE
Answer: A) CREATE DATABASE
Comments