TABLE 1) market_p_userdata (columns -> seller_id, image)
TABLE 2) market_product (columns -> seller_id, magepro_id)
TABLE 3) catalog_category_product?(columns -> product_id)
TABLE 4) customer_entity (columns-> entity_id)

TABLE 3) product_id (primary key) which is as a foriegn key in TABLE 2) named as magepro_id,

TABLE 4) enity_id(primary key) which is foreign key in TABLE 3) AND 2) named as seller_id,

TABLE 2) seller_id(primary key) which is foreign key in TABLE 1) named as seller_id,