Truncate vs delete:
2 types of Insert into students table:
Create a students table with following fields and constraints.
- Roll_No (No null values + should be unique)
- Name (No Null values accepted)
- Age (Should accept only values ranging 5 to 15)
- Parents_Email (Should be unique)
- Address (If no address is mentioned then it should show “-“)
4 types of constraints while creating table:
Update multiple records:
Update exercise:
Mode of working Update cmd:
Querying schema:
Inner Join:
Use classicmodels. Show the total sales done by each customer using below tables and sort it by highest to lowest sales.
Sales = SUM(priceEach * quantityOrdered)
- Customers
- Orders
- Orderdetails
Full outer join:
select
c.customernumber, c.customername, count(o.ordernumber) as Total_orders
from
customers c
left join
orders o
on
c.customerNumber = o.customerNumber
group by
c.customernumber, c.customername
union
select
c.customernumber, c.customername, count(o.ordernumber) as Total_orders
from
customers c
Right join
orders o
on
c.customerNumber = o.customerNumber
group by
c.customernumber, c.customername;
TCL commands:
Write the insert query, update query and delete query under Start Transaction. Use savepoint for each transaction. Check Rollback and Rollback to savepoint
Alter:
Task: Find the country names beginning with letter A, letter B, and letter C from customer table.
Categorize the customers into High, Medium and Low values with respect to creditLimit column
Case statement:
Task:
Find the total amount for each month of each year from payments table.
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