Campaigns containing at least two creatives

Get a list of advertising campaigns that include two or more creatives.

CREATE TABLE campaigns (
    id INT PRIMARY KEY,
    name VARCHAR(128) NOT NULL,
    start_date DATE NOT NULL DEFAULT CURRENT_TIMESTAMP,
    end_date DATE NOT NULL
);

CREATE TABLE ads (
    id INT PRIMARY KEY,
    name VARCHAR(128) NOT NULL,
    type VARCHAR(64) NOT NULL,
    cost INT NOT NULL,
    campaign_id INT REFERENCES campaigns(id)
);

CREATE TABLE creatives (
    id INT PRIMARY KEY,
    picture VARCHAR(256) NOT NULL,
    ad_id INT REFERENCES ads(id)
);