How many architects haven't built a mill before year 1850?
CREATE TABLE architect (
    id text,
    name text,
    nationality text,
    gender text
)

CREATE TABLE mill (
    architect_id number,
    id number,
    location text,
    name text,
    type text,
    built_year number,
    notes text
)

CREATE TABLE bridge (
    architect_id number,
    id number,
    name text,
    location text,
    length_meters number,
    length_feet number
)
SELECT COUNT(*) FROM architect WHERE NOT id IN (SELECT architect_id FROM mill WHERE built_year < 1850)
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: How many architects haven't built a mill before year 1850? ### Input: CREATE TABLE architect (
    id text,
    name text,
    nationality text,
    gender text
)

CREATE TABLE mill (
    architect_id number,
    id number,
    location text,
    name text,
    type text,
    built_year number,
    notes text
)

CREATE TABLE bridge (
    architect_id number,
    id number,
    name text,
    location text,
    length_meters number,
    length_feet number
) ### Response: SELECT COUNT(*) FROM architect WHERE NOT id IN (SELECT architect_id FROM mill WHERE built_year < 1850)