# Redis Cheatsheet
# All the commands you need to know


redis-server /path/redis.conf  # start redis with the related configuration file
redis-cli                      # opens a redis prompt


# Strings.


APPEND key value                  # append a value to a key
BITCOUNT key [start end]          # count set bits in a string
SET key value                     # set value in key
SETNX key value                   # set if not exist value in key
MSET key value [key value ...]    # set multiple keys to multiple values
MSETNX key value [key value ...]  # set multiple keys to multiple values, only if none of the keys exist
GET key                           # get value in key
GETRANGE key value                # get a substring value of a key and return its old value
MGET key [key ...]                # get the values of all the given keys
INCR key                          # increment value in key
INCRBY key increment              # increment the integer value of a key by the given amount
INCRBYFLOAT key increment         # increment the float value of a key by the given amount
DECR key                          # decrement the integer value of key by one
DECRBY key decrement              # decrement the integer value of a key by the given number
DEL key                           # delete key

EXPIRE key 120                    # key will be deleted in 120 seconds
TTL key                           # returns the number of seconds until a key is deleted


# Lists.
# A list is a series of ordered values.


RPUSH list value  # puts the new value at the end of the list
LPUSH list value  # puts the new value at the start of the list
LRANGE list 0 1   # gives a subset of the list
LLEN list         # returns the current length of the list
LPOP list         # removes the first element from the list and returns it
RPOP list         # removes the last element from the list and returns it


# Sets.
# A set is similar to a list, except it does not have a specific order and each element may only appear once. 


SADD myset value       # adds the given value to the set
SREM myset value       # removes the given value from the set
SISMEMBER myset value  # tests if the given value is in the set.
SMEMBERS myset         # returns a list of all the members of this set
SUNION myset otherset  # combines two or more sets and returns the list of all elements


# Sorted Sets
# A sorted set is similar to a regular set, but now each value has an associated score.
# This score is used to sort the elements in the set.


ZADD mysset score value  # adds the given value with the score to the set
ZRANGE mysset 0 2        # returns a subset of the sorted set

ZRANGEBYSCORE key min max [WITHSCORES] [LIMIT offset count]  # return a range of members in a sorted set, by score

# Hashes
# Hashes are maps between string fields and string values, so they are the perfect data type to represent objects.


HSET user:1000 name "John Smith"       # sets name to user #1000
HSET user:1000 email "john@smith.com"  # sets email to user #1000
HGET user:1001 name                    # returns the name for the user #1000
HGETALL user:1000                      # gets bak the saved data for the hash

HMSET user:1001 name "John Smith" email "john@smith.com"  # sets multiple fields at once

HINCRBY user:1000 visits 1  # increments value in hash by X
HDEL user:1000 visits       # deletes value in hash