redis删除多个键出现问题

Question

在看《redis入门指南》这篇文章中，第三章第二节介绍删除键的时候，有这样一段描述：

DEL命令的参数不支持通配符，但我们可以结合Linux的管道和xargs命令自己实现删除所有符合规则的键。比如要删除所有以“user:”开头的键，就可以执行redis-cli
KEYS "user:" | xargs redis-cli
DEL。另外，由于DEL命令支持多个键作为参数，所以还可以执行redis-cli DEL 'redis-cli KEYS
"user:"'来达到同样的效果，性能更好。

但是我测试的时候，第一个结合管道的命令能起作用，但是第二个貌似不起作用。
刚学习redis，请大神指教。

Answer 1

You read it wrong.

` and ' are two different things.

What they wrote is

他们写的是
redis-cli DEL `redis-cli KEYS "user:"`

你写的是
redis-cli DEL 'redis-cli KEYS "user:"'

Pay attention to the difference.

Single quotes directly treat the content within the single quotes as a string,
redis-cli DEL 'redis-cli KEYS "user:"'redis-cli DEL 'redis-cli KEYS "user:"'
就是删除redis中名叫redis-cli KEYS "user:" is to delete the key named

in redis,

The back quotes are to first execute the content in the back quotes to get the result, that is to say,

redis-cli DEL `redis-cli KEYS "user:"`

redis-cli KEYS "user:"The first thing to execute is , and the result is taken out (for example:)

user01
user02
user03

Then execute

redis-cli DEL user01 \n user02 \n user03

This problem is not with redis, but with the difference between single quotes and back quotes in the shell. 🎜