not exists与exists的用法示例

SELECT COUNT(*) 
FROM mc_store s 
WHERE 
  NOT Exists(
        SELECT 1 FROM mc_payeestore_rel ps WHERE ps.store_id = s.id
  );
--not exists 是exists的反面

SELECT COUNT(*) 
FROM mc_store s 
WHERE 
    Exists(
          SELECT 1 FROM mc_payeestore_rel ps WHERE ps.store_id = s.id
    );