SQL Programming Advanced Quiz 5

1. Write a SQL query to add a new column "age" to table "students".

2. Write a SQL query to remove all rows from a table but keep its structure.

3. Write a SQL query to create an index on column "email" in table "users".

4. Write a SQL query to remove a column "phone" from table "contacts".

5. Write a SQL query to find duplicate records in a table.

6. Write a SQL query to select the total sales for each month.

7. Write a SQL query to find the minimum and maximum salary in "employees".

8. Write a SQL query to change the data type of column "price" to DECIMAL(10,2) in "products".

9. Write a SQL query to rename table "orders" to "customer_orders".

10. Write a SQL query to add a NOT NULL constraint to column "username" in table "accounts".