Left Join vs Inner Join | Dataford Interview Questions

Explain the difference between a left join and an inner join in SQL.

Use the Firstnet Global customer and order data to demonstrate the difference with query results. Show all customers and indicate whether an order match exists.

Output

One row per Firstnet Global customer and matching order, including customers without orders.
Columns: customer_id, customer_name, order_id, and match_status.
Sort by customer_id, then order_id, with unmatched customers shown clearly.

Schema

customers

Column	Type	Description
customer_idPK	INT	Unique Firstnet Global customer identifier
customer_name	VARCHAR(100)	Customer display name

orders

Column	Type	Description
order_idPK	INT	Unique order identifier
customer_id	INT	Customer associated with the order
order_status	VARCHAR(30)	Current order status

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Problem