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Tesla is investigating production bottlenecks and they need your help to extract the relevant data. Write a query that determines which parts with the assembly steps have initiated the assembly process but remain unfinished.
Assumptions:
This question is straightforward, so let's approach it with simplicity in both thinking and solution.
Effective April 11th 2023, the problem statement and assumptions were updated to enhance clarity.
Column Name | Type |
---|---|
part | string |
finish_date | datetime |
assembly_step | integer |
part | finish_date | assembly_step |
---|---|---|
battery | 01/22/2022 00:00:00 | 1 |
battery | 02/22/2022 00:00:00 | 2 |
battery | 03/22/2022 00:00:00 | 3 |
bumper | 01/22/2022 00:00:00 | 1 |
bumper | 02/22/2022 00:00:00 | 2 |
bumper | 3 | |
bumper | 4 |
part | assembly_step |
---|---|
bumper | 3 |
bumper | 4 |
The bumpers in step 3 and 4 are the only item that remains unfinished as it lacks a recorded finish date.
The dataset you are querying against may have different input & output - this is just an example!
Great news! The parts table already includes all parts currently in production, so no additional filtering is necessary to exclude non-production parts.
To extract unfinished parts, we can simply filter for rows where the column contains no data, indicated by a NULL value.
PostgreSQL 14