兄弟，又是你啊，这个问题还没解决啊？

INSERT INTO customer(email,address,name,phone,phone2) 
SELECT email,address,name,phone,phone2
FROM buy
WHERE (phone,phone2) not in (SELECT phone,phone2 FROM customer)
GROUP BY phone,phone2;

这种写法是各自对应的，如果遇上类似 要插入的 phone 跟 被插入表中的 phone2 重复时，这种 case, 这条是SQL处理不了的。

麻烦点，把条件分开写

INSERT INTO customer(email,address,name,phone,phone2) 
    SELECT email,address,name,phone,phone2
    FROM buy
    WHERE phone not in (SELECT phone FROM customer)
        AND phone not in (SELECT phone2 FROM customer)
        AND phone2 not in (SELECT phone FROM customer)
        AND phone2 not in (SELECT phone2 FROM customer)
    GROUP BY phone,phone2;
    

类似这种可以试试。