Checking unconnected copper in PCB Design - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select all copper areas not connected to any net.

PCB Design

SELECT * FROM copper_areas WHERE net_id IS [1];

Drag options to blanks, or click blank then click option'

ANOT NULL

B0

C''

DNULL

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 or empty string instead of NULL to check unconnected copper.

Unconnected copper areas have a NULL net_id, meaning they are not linked to any net.

2fill in blank

medium

Complete the code to count unconnected copper areas in the PCB.

PCB Design

SELECT COUNT(*) FROM copper_areas WHERE net_id IS [1];

Drag options to blanks, or click blank then click option'

ANULL

BNOT NULL

C0

D''

Attempts:

3 left

💡 Hint

Common Mistakes

Counting net_id = 0 or empty string instead of NULL.

Counting unconnected copper means counting rows where net_id is NULL.

3fill in blank

hard

Fix the error in the code to find unconnected copper areas.

PCB Design

SELECT * FROM copper_areas WHERE net_id [1] NULL;

Drag options to blanks, or click blank then click option'

AFALSE

BIS

C''

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using '=' operator with NULL causing no results.

Using '=' to compare with NULL is incorrect in SQL; use 'IS NULL' instead.

4fill in blank

hard

Fill both blanks to filter unconnected copper areas and order by area size descending.

PCB Design

SELECT * FROM copper_areas WHERE net_id IS [1] ORDER BY area [2];

Drag options to blanks, or click blank then click option'

ANULL

BASC

CDESC

DNOT NULL

Attempts:

3 left

💡 Hint

Common Mistakes

Ordering ascending instead of descending.

Filtering with NOT NULL instead of NULL.

We filter where net_id IS NULL and order by area descending to see largest unconnected copper first.

5fill in blank

hard

Fill all three blanks to create a report showing unconnected copper count per layer, ordered by count descending.

PCB Design

SELECT layer, COUNT(*) AS unconnected_count FROM copper_areas WHERE net_id IS [1] GROUP BY [2] ORDER BY unconnected_count [3];

Drag options to blanks, or click blank then click option'

ANULL

Blayer

CDESC

Dnet_id

Attempts:

3 left

💡 Hint

Common Mistakes

Grouping by wrong column.

Ordering ascending instead of descending.

We filter unconnected copper with 'IS NULL', group by layer, and order counts descending.