update an attribute of a row postgres code example
Example: postgres updatet_at field
CREATE OR REPLACE FUNCTION trigger_set_timestamp()
RETURNS TRIGGER AS $$
BEGIN
NEW.updated_at = NOW();
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
CREATE TABLE my_table (
id SERIAL NOT NULL PRIMARY KEY,
content TEXT,
created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);
CREATE TRIGGER set_timestamp
BEFORE UPDATE ON my_table
FOR EACH ROW
EXECUTE PROCEDURE trigger_set_timestamp();