Postgres Practice 2/12

JSONB: filter rows with @>

attrs->>'wireless' = 'true' would work for filtering on a single JSON field, but it means comparing against the text 'true', not a real boolean - easy to get subtly wrong once the JSON gets more nested. Postgres has a better tool for "does this JSON document contain this shape": the @> containment operator. attrs @> '{"wireless": true}' asks "does the attrs JSON contain a wireless key set to true, alongside whatever else it has?" - and it compares against the real JSON value, not text.

Same products table as the last lesson: id, name, attrs (JSONB, with a "wireless" boolean in every row).

Your task: return the name of every product where attrs shows wireless as true.

You'll practice:

Filtering on a JSONB field's real type (boolean) with @>, not a text comparison
Writing a JSON literal inside a SQL string

-- Return the name of every product where attrs shows wireless: true.
SELECT name, attrs FROM products;