Mysql3个字段，任何一个字段的值相同则为重复，语句应该怎么写？

mysql中3个字段，如果这3个字段中，任何一个字段有重复值，则为重复，应该怎么写？
比如
a b c
1 2 3
4 5 3
c字段重复了，那么这两条记录就算重复。

我试了这个语句：

SELECT DISTINCT a,b,c FROM `table`

结果不对，查出来的是3个字段都相同才排除
而我要的是3个字段中任意一个字段的值相同就排除

等于说实现的效果跟把这3个字段设置成唯一键值一样的导量，查询这3个字段的值都为唯一的结果

---

select distinct id 
from (
    select distinct a from table
        union
    select distinct b from table
        union 
    select distinct c from table
) as t

---

sql语句有点复杂：

SELECT
    t1.a,
    t1.b,
    t1.c
FROM
    demo AS t1
WHERE
    t1.a NOT IN (
        SELECT
            a
        FROM
            demo
        WHERE
            t1.id != id
    )
AND
t1.a NOT IN (
        SELECT
            b
        FROM
            demo
        WHERE
            t1.id != id
    )
AND
t1.a NOT IN (
        SELECT
            c
        FROM
            demo
        WHERE
            t1.id != id
    )
AND
t1.b NOT IN (
        SELECT
            a
        FROM
            demo
        WHERE
            t1.id != id
    )
AND
t1.b NOT IN (
        SELECT
            b
        FROM
            demo
        WHERE
            t1.id != id
    )
AND
t1.b NOT IN (
        SELECT
            c
        FROM
            demo
        WHERE
            t1.id != id
    )
AND
t1.c NOT IN (
        SELECT
            a
        FROM
            demo
        WHERE
            t1.id != id
    )
AND
t1.c NOT IN (
        SELECT
            b
        FROM
            demo
        WHERE
            t1.id != id
    )
AND
t1.c NOT IN (
        SELECT
            c
        FROM
            demo
        WHERE
            t1.id != id
    )

---

但是你想查出什么呢…？比如1 2 3和1 4 3我应该留下哪个呢？这个查询的意义在哪里呢？