Redis HASH data type

redis-hash.rb

127.0.0.1:6379> HSET my_hash key1 1 # Initializes a HASH my_hash with key-value key1: 1
(integer) 1
127.0.0.1:6379> HSET my_hash key2 value2 # Sets another key-value pair key2: value2 in my_hash
(integer) 1
127.0.0.1:6379> HGET my_hash key1 # GET the data for key1 in my_hash
"1"
127.0.0.1:6379> HGET my_hash key2 # GET the data for key2 in my_hash
"value2"
127.0.0.1:6379> HGETALL my_hash # GET the complete data in my_hash
1) "key1"
2) "1"
3) "key2"
4) "value2"
127.0.0.1:6379> HDEL my_hash unknown_key # DELETE the data for non-existing key unknown_key in my_hash. Returns 0 as failure
(integer) 0
127.0.0.1:6379> HDEL my_hash key1 # DELETE the data for an existing key key1 in my_hash. Returns 1 as success
(integer) 1
127.0.0.1:6379> HGETALL my_hash # GETALL the data in my_hash. 
1) "key2"
2) "value2"
127.0.0.1:6379> HDEL my_hash key1 # Try to DELETE the data for an already deleted key key1 in my_hash. Returns 0 as failure
(integer) 0
127.0.0.1:6379> HGET my_hash key1 # GET the data for key1 in my_hash. Returns 0 as failure
(nil)