# Task: 017

**Database:** retails  

## Question
Find the customer with the largest order value in each market segment.


## Gold Query

```sql
WITH order_totals AS (
SELECT c_mktsegment, c.c_custkey, c.c_name, SUM(o.o_totalprice) AS total_o_totalprice
FROM customer c
JOIN orders o ON c.c_custkey = o.o_custkey
GROUP BY c_mktsegment, c.c_custkey, c.c_name
)
SELECT
ot.c_mktsegment AS market_segment,
ot.c_custkey AS customer_key,
ot.c_name AS customer_name,
ot.total_o_totalprice AS largest_value
FROM order_totals ot
JOIN (
SELECT ot2.c_mktsegment, MAX(ot2.total_o_totalprice) AS max_value
FROM order_totals ot2
GROUP BY ot2.c_mktsegment
) AS max_val ON ot.c_mktsegment = max_val.c_mktsegment AND ot.total_o_totalprice = max_val.max_value;
```

**Execution Result:**

| market_segment   |   customer_key | customer_name      |   largest_value |
|------------------|----------------|--------------------|-----------------|
| AUTOMOBILE       |         114308 | Customer#000114308 |       5486668.8 |
| BUILDING         |          58421 | Customer#000058421 |       5487155.8 |
| FURNITURE        |          41290 | Customer#000041290 |       5473361.7 |
| HOUSEHOLD        |          79933 | Customer#000079933 |       5928489.4 |
| MACHINERY        |          58387 | Customer#000058387 |       5719569.4 |

*5 rows*