Redis Hashes are maps between the string fields and the string values. Hence, they are the perfect data type to represent objects.
In Redis, every hash can store up to more than 4 billion field-value pairs.
redis 127.0.0.1:6379> HMSET howcodex name "redis tutorial" description "redis basic commands for caching" likes 20 visitors 23000 OK redis 127.0.0.1:6379> HGETALL howcodex 1) "name" 2) "redis tutorial" 3) "description" 4) "redis basic commands for caching" 5) "likes" 6) "20" 7) "visitors" 8) "23000"
In the above example, we have set Redis tutorials detail (name, description, likes, visitors) in hash named ‘howcodex’.
Following table lists some basic commands related to hash.
Sr.No | Command & Description |
---|---|
1 | HDEL key field2 [field2]
Deletes one or more hash fields. |
2 | HEXISTS key field
Determines whether a hash field exists or not. |
3 | HGET key field
Gets the value of a hash field stored at the specified key. |
4 | HGETALL key
Gets all the fields and values stored in a hash at the specified key |
5 | HINCRBY key field increment
Increments the integer value of a hash field by the given number |
6 | HINCRBYFLOAT key field increment
Increments the float value of a hash field by the given amount |
7 | HKEYS key
Gets all the fields in a hash |
8 | HLEN key
Gets the number of fields in a hash |
9 | HMGET key field1 [field2]
Gets the values of all the given hash fields |
10 | HMSET key field1 value1 [field2 value2 ]
Sets multiple hash fields to multiple values |
11 | HSET key field value
Sets the string value of a hash field |
12 | HSETNX key field value
Sets the value of a hash field, only if the field does not exist |
13 | HVALS key
Gets all the values in a hash |
14 | HSCAN key cursor [MATCH pattern] [COUNT count]
Incrementally iterates hash fields and associated values |