Quiz for UPDATE

Q1: What does the UPDATE statement do in SQL?

A. Adds new rows to the table B. Modifies existing records in a table C. Deletes records from a table D. Changes table structure

Q2: Which clause is mandatory in an UPDATE statement?

A. WHERE B. SET C. ORDER BY D. GROUP BY

Q3: What happens if the WHERE clause is omitted in an UPDATE statement?

A. All rows in the table are updated B. Only the first row is updated C. No rows are updated D. An error occurs

Q4: Which of the following is a valid syntax for an UPDATE statement?

A. UPDATE table SET column1 = value1, column2 = value2 WHERE condition; B. UPDATE table SET column1 = value1, column2 WHERE condition; C. UPDATE table SET column1 = value1 WHERE condition; D. UPDATE table column1 = value1 WHERE condition;

Q5: Can you update multiple columns in one UPDATE statement?

A. Yes, by separating columns with commas B. No C. Only if columns are in the same table D. Only one column can be updated

Q6: Which SQL statement will update the price of a product to 100 where the product_id is 10?

A. UPDATE products SET price = 100 WHERE product_id = 10; B. UPDATE products price = 100 WHERE product_id = 10; C. UPDATE products SET price 100 WHERE product_id = 10; D. UPDATE products price = 100 product_id = 10;

Q7: What is the purpose of the WHERE clause in an UPDATE statement?

A. It specifies the rows to be updated B. It defines the columns to be updated C. It groups rows for aggregation D. It deletes rows

Q8: Which of the following is true about the UPDATE statement?

A. It can only modify one row at a time B. It requires all columns to be updated C. It can update multiple rows at once D. It only works with text data types

Q9: Which of the following would prevent an UPDATE operation?

A. The table is locked B. There is no WHERE clause C. The database is in read-only mode D. All of the above

Q10: Which of the following is a common use of the UPDATE statement?

A. Changing an employee’s salary B. Removing a row from a table C. Inserting a new record D. Creating a new table

Q11: Can you use the UPDATE statement to modify NULL values?

A. Yes, by explicitly setting them to NULL B. No, NULL values cannot be updated C. Yes, but only in non-indexed columns D. No, NULL is immutable

Q12: What happens if you update a column that has a UNIQUE constraint with a duplicate value?

A. The operation is successful B. An error is raised C. The duplicate value is automatically removed D. The database skips the row

Q13: Can you use subqueries in an UPDATE statement?

A. Yes B. No C. Only in SELECT statements D. Only in DELETE statements

Q14: Which statement will update the price of all products by 10%?

A. UPDATE products SET price = price * 1.1; B. UPDATE products SET price = price + 10%; C. UPDATE products SET price = 10% WHERE product_id; D. UPDATE products SET price = price + 10;

Q15: What does the SET clause in an UPDATE statement do?

A. It specifies the condition for row selection B. It specifies the columns to update and their new values C. It creates a new table D. It deletes rows from a table

Q16: Which of the following will update the age of a user with user_id 5 to 25?

A. UPDATE users SET age = 25 WHERE user_id = 5; B. UPDATE users SET user_id = 5, age = 25; C. UPDATE users SET age = 25; D. UPDATE users SET user_id = 5;

Q17: Which of the following will update the name of all customers to "Unknown"?

A. UPDATE customers SET name = "Unknown"; B. UPDATE customers SET name = "Unknown" WHERE name IS NULL; C. UPDATE customers SET name = NULL WHERE name = "Unknown"; D. UPDATE customers WHERE name IS NULL;

Q18: Which is the correct order for an UPDATE statement?

A. UPDATE table SET column = value WHERE condition; B. SET table UPDATE column = value WHERE condition; C. UPDATE column SET table = value WHERE condition; D. WHERE table column = value UPDATE;

Q19: Which of the following can you use in an UPDATE statement to join multiple tables?

A. JOIN B. IN C. EXISTS D. GROUP BY

Q20: Can you use a SELECT statement to provide values in an UPDATE statement?

A. Yes, using a subquery B. No, only literals can be used C. Yes, but only for numeric columns D. No, it can only be used for INSERT