--DROP TABLE user_messages PURGE;
CREATE TABLE user_messages (
    app_id              NUMBER(4)       CONSTRAINT nn_user_messages_app_id      NOT NULL,
    user_id             VARCHAR2(30)    CONSTRAINT nn_user_messages_user_id     NOT NULL,
    message_id          INTEGER         CONSTRAINT nn_user_messages_message_id  NOT NULL,   -- log_id
    message_type        VARCHAR2(16),
    message_payload     VARCHAR2(2000),
    session_id          INTEGER,
    --
    created_by          VARCHAR2(30),
    created_at          DATE,
    delivered_at        DATE,
    --
    CONSTRAINT pk_user_messages
        PRIMARY KEY (app_id, user_id, message_id),
    --
    CONSTRAINT fk_user_messages_app_id
        FOREIGN KEY (app_id)
        REFERENCES apps (app_id),
    --
    CONSTRAINT fk_user_messages_user_id
        FOREIGN KEY (user_id)
        REFERENCES users (user_id)
        DEFERRABLE INITIALLY DEFERRED
)
STORAGE (BUFFER_POOL KEEP);
--
COMMENT ON TABLE  user_messages                     IS '[CORE] Messages for users';
--
COMMENT ON COLUMN user_messages.app_id              IS 'APEX application ID';
COMMENT ON COLUMN user_messages.user_id             IS 'User ID from USERS table';
COMMENT ON COLUMN user_messages.message_id          IS 'Message id';
COMMENT ON COLUMN user_messages.message_type        IS 'Message type';
COMMENT ON COLUMN user_messages.message_payload     IS 'Message itself';
COMMENT ON COLUMN user_messages.session_id          IS 'Session id';
COMMENT ON COLUMN user_messages.delivered_at        IS 'Stamp of delivery';