SQL and Database Quiz

Which command is used to rollback the last transaction?

• COMMIT;

• ROLLBACK;

• SAVEPOINT;

• UNDO;

How to add a primary key constraint to an existing table?

• ALTER TABLE Employee ADD PRIMARY KEY (EMPNO);

• ALTER Employee ADD PRIMARY KEY (EMPNO);

• ADD PRIMARY KEY TO Employee (EMPNO);

• ALTER Employee TABLE ADD PRIMARY KEY (EMPNO);

How to add a NOT NULL constraint to a column?

• ALTER TABLE Employee ADD CONSTRAINT NOT NULL (EMPNO);

• ALTER TABLE Employee MODIFY EMPNO NOT NULL;

• ALTER TABLE Employee ADD NOT NULL (EMPNO);

• ALTER Employee MODIFY COLUMN EMPNO NOT NULL;

Which command is used to insert a new record into a table?

• INSERT INTO Employee VALUES (101, 'John', 'Manager', 1001, 5000, NULL);

• ADD INTO Employee VALUES (101, 'John', 'Manager', 1001, 5000, NULL);

• INSERT INTO Employee SET (101, 'John', 'Manager', 1001, 5000, NULL);

• INSERT INTO Employee SET VALUES (101, 'John', 'Manager', 1001, 5000, NULL);

How to add a new column to an existing table?

• ALTER TABLE Employee ADD COLUMN commission DECIMAL(10,2);

• ALTER Employee ADD COLUMN commission DECIMAL(10,2);

• ALTER TABLE Employee MODIFY commission DECIMAL(10,2);

• ALTER Employee TABLE ADD COLUMN commission DECIMAL(10,2);

How to update the details of a column in a table?

• UPDATE Employee SET JOB = 'Developer' WHERE EMPNO = 101;

• MODIFY Employee SET JOB = 'Developer' WHERE EMPNO = 101;

• CHANGE Employee SET JOB = 'Developer' WHERE EMPNO = 101;

• ALTER Employee SET JOB = 'Developer' WHERE EMPNO = 101;

How to rename a column in a table?

• ALTER TABLE Employee RENAME COLUMN commission TO bonus;

• CHANGE Employee RENAME COLUMN commission TO bonus;

• MODIFY Employee RENAME COLUMN commission TO bonus;

• RENAME Employee RENAME COLUMN commission TO bonus;

Which command is used to delete a record from a table?

• DELETE FROM Employee WHERE EMPNO = 105;

• REMOVE FROM Employee WHERE EMPNO = 105;

• DROP FROM Employee WHERE EMPNO = 105;

• ERASE FROM Employee WHERE EMPNO = 105;

How to count the number of employee names in a table?

• SELECT COUNT(E_name) FROM Employee;

• SELECT TOTAL(E_name) FROM Employee;

• SELECT SUM(E_name) FROM Employee;

• SELECT NUMBER(E_name) FROM Employee;

How to find the maximum age in a table?

• SELECT MAX(Age) FROM Employee;

• SELECT HIGHEST(Age) FROM Employee;

• SELECT BIGGEST(Age) FROM Employee;

• SELECT LARGEST(Age) FROM Employee;