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N035-E2 Tier 3 · Intermediate · easy ecommerce · Brightlane

Return the character count of the product code `'SKU-4821-B-XL'`

Part of String Functions (LENGTH, UPPER, LOWER, TRIM, SUBSTRING) in SQL

The problem

Brightlane's catalog validation rule checks that product codes do not exceed 12 characters.

Write a query to return the character count of the product code 'SKU-4821-B-XL'.

Output:

  • A single row with one column, code_length, containing the count as a number.
Schema · ecommerce 5 tables
categories
id integer
name text
parent_id? integer
products
id integer
name text
category_id integer
price numeric
stock_qty integer
attributes? jsonb
order_items
id integer
order_id integer
product_id integer
quantity integer
unit_price numeric
customers
id integer
name text
email text
city? text
country text
created_at timestamptz
is_active boolean
orders
id integer
customer_id integer
ordered_at timestamptz
status text
total_amount numeric
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Solution query
SELECT
  LENGTH('SKU-4821-B-XL') AS code_length

The shape

LENGTH('SKU-4821-B-XL') returns the integer 13, the character count of the product code. The validation rule caps codes at 12, so this value being one over the cap is the signal the catalog check is built around.

Clause by clause

  • SELECT LENGTH('SKU-4821-B-XL') AS code_length measures the literal and returns the count as a single integer column. LENGTH counts characters, not bytes: every letter, digit, and hyphen in the code contributes one to the total, which adds up to 13.
  • There is no FROM because the input is a literal embedded in the query. The function takes one string and returns one number; nothing else needs to be in scope.

Why this and not measuring against the cap inline

The output spec asks for the count itself, not a pass-or-fail flag. Returning the raw 13 lets the validation layer decide what counts as over the cap and lets a human reading the result see exactly how far over it is. LENGTH is the right tool here because the question is how long the string is; turning the answer into a boolean is a separate downstream decision.

You practiced LENGTH(...) — return the character count of a string as a number, the basic measurement for validating against a length cap.

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