redis设计之初就不是为了处理“关系”的，而mysql就是关系型数据库。虽然不建议，但是redis也可以实现。你可以用用户的id作健，把这些image存进一个list中：
$redis->rPush("user_1", "./1zxcz12ad.jpg");
$redis->rPush("user_1", "./zsad12sad.jpg");
$redis->rPush("user_2", "./12eaxx12sw1212.jpg");
然后可以通过：$redis->lRange('user_1', 0, -1);取到这个list。

只能用hash了。

user主表用hash来做。
pics从表同样用hash来做，只是field用pics的ID

HSET User 1 "{name: 'jack', age: 5, Pics: [1, 2]}"

HSET User 2 "{name: 'rose', age: 12, Pics: [4]}"

HSET Pics 1 "{img_url: './1zxcz12ad.jpg', User: 1'}"
HSET Pics 2 "{img_url: './zsad12sad.jpg', User: 1'}"
HSET Pics 4 "{img_url: './12eaxx12sw1212.jpg', User: 2'}"

适用于1对多或者1对1 (ZADD key score member)：

ZADD User_Pics 1 1
ZADD User_Pics 1 2
ZADD User_Pics 2 4

查询user 2的pics (ZRANGEBYSCORE key min max [WITHSCORES])

ZRANGEBYSCORE User_Pics 2 2

查询user 1和2的pics

ZRANGEBYSCORE User_Pics 1 2 WITHSCORES

查询pics 4的user (ZSCORE key member)

ZSCORE User_Pics 4

HSET User 1 "{name: 'jack', age: 5, Pics: [1, 2]}"

HSET User 2 "{name: 'rose', age: 12, Pics: [1，2]}"

HSET Pics 1 "{img_url: './1zxcz12ad.jpg', User: [1, 2]'}"

HSET Pics 2 "{img_url: './zsad12sad.jpg', User: [1, 2]'}"

对于多对多 (值为 "userID-PicsID" )：
ZADD User_Pics 1 "1-1"
ZADD User_Pics 1 "1-2"
ZADD User_Pics 2 "2-1"
ZADD User_Pics 2 "2-2"

查询user 2的pics

ZRANGEBYSCORE User_Pics 2 2

查询user 1和2的pics

ZRANGEBYSCORE User_Pics 1 2 WITHSCORES

ZADD Pics_User 1 "1-1"
ZADD Pics_User 1 "2-1"
ZADD Pics_User 2 "1-2"
ZADD Pics_User 2 "2-2"

查询pics1 1的user

ZRANGEBYSCORE Pics_User 1 1

查询pics1 1和2的user

ZRANGEBYSCORE Pics_User 1 2 WITHSCORES