如果商店只有一个公司id，我有下面的查询来插入数据。如果已经有两个公司id，我不想插入数据。逻辑看起来很简单，但是如果有2个或更多的公司id，我不知道如何防止插入数据。在下面的查询中，它不断插入数据。我是一个sql的新手，所以一些例子或提示将是一个很大的帮助！我很想听到你的消息！

INSERT INTO customers (
    id, 
      name, 
      phone, 
      mail, 
      address
)
    SELECT 
      company.id, 
      company.name, 
      company.phone, 
      company.mail, 
      company.address, 
    FROM 
      company 
      LEFT JOIN shops ON company.id = shops.id 
    WHERE 
      shops.company_id IN (
        SELECT 
          company.id 
        FROM 
          company 
          LEFT JOIN shops ON company.id = shops.company_id 
        WHERE 
          shops.id IN (1,2,41)
      )
    GROUP BY 
      shops.company_id 
    having 
      count(shops.company_id) >= 1 ;