MCQs on Data Manipulation Language (DML) | Data Operations

Data Manipulation Language (DML)

Which of the following is NOT a part of Data Manipulation Language (DML)?
- a) INSERT
- b) DELETE
- c) COMMIT
- d) SELECT
In SQL, which command is used to modify data in existing rows?
- a) SELECT
- b) UPDATE
- c) ALTER
- d) MERGE
DML commands directly affect:
- a) Database schema
- b) Data within tables
- c) User privileges
- d) Views

Inserting Data into Tables

Which SQL command is used to add new rows to a table?
- a) INSERT
- b) CREATE
- c) UPDATE
- d) DELETE
If a table has columns name, age, and city, which of the following is the correct way to insert a row?
- a) INSERT INTO table (name, age, city) VALUES ("Alice", 25, "NY");
- b) INSERT INTO table VALUES (name="Alice", age=25, city="NY");
- c) INSERT VALUES INTO table ("Alice", 25, "NY");
- d) ADD INTO table VALUES ("Alice", 25, "NY");
To insert data into only specific columns of a table, we:
- a) Leave the column list empty
- b) Specify only the required columns
- c) Use the ALTER command
- d) Leave out the column values
What happens if we omit a NOT NULL column while inserting data?
- a) It auto-fills with default values
- b) The insert operation fails
- c) The column is left blank
- d) The data gets automatically updated

Updating and Deleting Data

Which SQL command is used to change existing data in a table?
- a) INSERT
- b) DELETE
- c) ALTER
- d) UPDATE
Which of these commands can remove all records from a table without deleting the table itself?
- a) DROP TABLE
- b) DELETE FROM table
- c) TRUNCATE TABLE
- d) CLEAR TABLE
If you want to delete records with a specific condition, which SQL keyword should you use?
- a) WHERE
- b) IF
- c) LIKE
- d) BETWEEN
Which of the following is true about the DELETE command?
- a) It removes the table structure.
- b) It can delete specific rows.
- c) It cannot delete multiple rows at once.
- d) It is the same as TRUNCATE.
To update the salary of employees in a specific department, which command would you use?
- a) MODIFY
- b) UPDATE
- c) DELETE
- d) CHANGE

Using Transactions (COMMIT, ROLLBACK, and SAVEPOINT)

Which command is used to save the current state of a transaction permanently?
- a) ROLLBACK
- b) COMMIT
- c) SAVEPOINT
- d) EXIT
What is the purpose of the ROLLBACK command?
- a) To save changes permanently
- b) To delete all records in a table
- c) To undo changes in the current transaction
- d) To lock a table
In a transaction, the SAVEPOINT command is used to:
- a) Permanently save the transaction
- b) Roll back all changes
- c) Create a rollback point within the transaction
- d) Exit the transaction
Which command will undo all changes made since the last COMMIT?
- a) DELETE
- b) ROLLBACK
- c) SAVEPOINT
- d) TRUNCATE
What will happen if a ROLLBACK command is issued after a SAVEPOINT?
- a) Changes revert to the SAVEPOINT
- b) No changes are reverted
- c) All changes in the transaction are committed
- d) The transaction ends

Advanced Insert Techniques (Bulk Inserts, MERGE Statements)

Which command is suitable for inserting multiple rows of data in one statement?
- a) BULK INSERT
- b) INSERT ONE
- c) ADD ROWS
- d) MERGE
Which of the following commands allows conditional insert, update, or delete actions in SQL?
- a) JOIN
- b) MERGE
- c) UNION
- d) TRUNCATE
What does the MERGE statement typically require?
- a) A target table and source table
- b) Only a target table
- c) Only a source table
- d) No tables at all
To perform an update if a record exists, or insert if it does not, which command is ideal?
- a) INSERT
- b) MERGE
- c) CREATE
- d) DELETE
Which clause can be used within a MERGE statement for conditional actions?
- a) WHERE
- b) WHEN MATCHED
- c) SELECT
- d) HAVING

Subqueries in DML Statements

In SQL, a subquery is also known as:
- a) Main query
- b) Inner query
- c) Update query
- d) Base query
Which statement is true about subqueries?
- a) They must be used in the FROM clause only.
- b) They can be used in WHERE, SELECT, and FROM clauses.
- c) They are only used in DELETE statements.
- d) They cannot return a single value.
A subquery used in a WHERE clause is generally known as:
- a) Inline view
- b) Correlated subquery
- c) Derived table
- d) Predicate query
Which operator is commonly used with subqueries to compare values with multiple results from the subquery?
- a) IN
- b) LIKE
- c) JOIN
- d) MERGE
In which DML command can subqueries be used to determine values for insertion?
- a) INSERT
- b) DROP
- c) ALTER
- d) CREATE
Which DML command allows subqueries in both the SET and WHERE clauses?
- a) DELETE
- b) UPDATE
- c) INSERT
- d) SELECT
What type of subquery returns more than one row of results?
- a) Scalar subquery
- b) Row subquery
- c) Table subquery
- d) Column subquery
Subqueries that reference a column in the outer query are called:
- a) Correlated subqueries
- b) Non-correlated subqueries
- c) Inline views
- d) Derived tables

Qno	Answer
1	c) COMMIT
2	b) UPDATE
3	b) Data within tables
4	a) INSERT
5	a) `INSERT INTO table (name, age, city) VALUES ("Alice", 25, "NY");`
6	b) Specify only the required columns
7	b) The insert operation fails
8	d) UPDATE
9	c) TRUNCATE TABLE
10	a) WHERE
11	b) It can delete specific rows
12	b) UPDATE
13	b) COMMIT
14	c) To undo changes in the current transaction
15	c) Create a rollback point within the transaction
16	b) ROLLBACK
17	a) Changes revert to the SAVEPOINT
18	a) BULK INSERT
19	b) MERGE
20	a) A target table and source table
21	b) MERGE
22	b) WHEN MATCHED
23	b) Inner query
24	b) They can be used in WHERE, SELECT, and FROM clauses
25	b) Correlated subquery
26	a) IN
27	a) INSERT
28	b) UPDATE
29	c) Table subquery
30	a) Correlated subqueries

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