How to create LIKE operator search in Redis cache using nodejs?

问题

I have a question, is it possible to create a LIKE operator search in Redis? Similar to relational (mysql/oracle) database.

I have complex json:

   {"_id" : ObjectId("581c8b8854fdcd1ff8c944e0"),
"Objectcode" : "xxxxx",
"Objecttype" : "xxxx",
"docid" : "581c8b8554fdcd1ff8c93d10",
"description" : "Tags based search .... ",
"metaTags" : [ 
    "tag1", 
    "tag2", 
    "tag3", 
    "tag5", 
    "tag6", 
    "tag7", 
    "tag8", 
    "tag9", 
    "tag10"
],
"__v" : 0

}

and i want to search on array of metaTags how can i do it?

Thanks

回答1:

You can use MATCH commands to search data.

Eg: scan 0 MATCH *11*

Refer: http://redis.io/commands/scan

回答2:

You can use Redis *SCAN commands http://redis.io/commands/scan, depending of your type of data to filter by a pattern:

SCAN iterates the set of keys in the currently selected Redis database.

SSCAN iterates elements of Sets types.

HSCAN iterates fields of Hash types and their associated values.

ZSCAN iterates elements of Sorted Set types and their associated scores.

Never use KEYS in app code, because it may ruin performance.

The two major nodejs redis client libraries node_redis and ioredis support it, with some syntax sugar:

const keys = [];
const redis = new Redis(); // ioredis
redis.mset('foo1', 1, 'foo2', 1, 'foo3', 1, 'foo4', 1, 'foo10', 1, () => {
  const stream = redis.scanStream();
  stream.on('data', data => {
    keys = keys.concat(data);
  });
  stream.on('end', () => {
    assert.equal(keys.sort(), ['foo1', 'foo10', 'foo2', 'foo3', 'foo4']);
  });
});

来源：https://stackoverflow.com/questions/40761383/how-to-create-like-operator-search-in-redis-cache-using-nodejs

标签

node.js

Redis

node-redis