Project - Left Join Two Tables
You may have some registered customers who have not yet made a purchase.
Let us find out about them.
Your database ‘Customer’ has the following columns
- Customer_id (INT)
- Customer_Name (VARCHAR)
- Customer_Age (INT)
Your database ‘Purchase’ has the following columns
- Purchase_id (INT)
- Customer_id (INT)
- Purchase_amt (INT)
- Last_purchase_month (VARCHAR)
Task
Write a query that does the following
- Join the table ‘Customer’ and ‘Purchase’ using Customer_id as the common column in the table.
- Output the joined table
- The output should include the list of customers who haven’t made any purchases yet.
Expected output
| Customer_id | Customer_Name | Customer_Age | Purchase_id | Customer_id | Purchase_amt | Last_purchase_month |
|---|---|---|---|---|---|---|
| 1 | John | 15 | 1 | 1 | 100 | May |
| 2 | Sara | 16 | NULL | NULL | NULL | NULL |
| 3 | Adam | 17 | 36 | 3 | 300 | October |
| 4 | Emily | 15 | 2 | 4 | 50 | March |
| 5 | Tom | 16 | NULL | NULL | NULL | NULL |
| 6 | Amy | 17 | 3 | 6 | 200 | January |
| 7 | Mark | 15 | NULL | NULL | NULL | NULL |
| 8 | Olivia | 16 | NULL | NULL | NULL | NULL |
| 9 | David | 17 | 49 | 9 | 225 | July |
| 10 | Emma | 15 | 10 | 10 | 250 | April |