Redis Basic

Try this tutorial

http://try.redis.io/

• Set a key-value SET

  SET server:name "fido"

• Get value of a key GET

  GET server:name

• Check existing(1: true, 0 false) EXISTS

  EXISTS server:name⇒ 1

  EXISTS server:aaa⇒0

• Increment by 1 INCR

  SET c 1

  INCR c ⇒ 2

• Increment by x INCRBY

  INCRBY c 10 ⇒ 12

  INCR and INCRBY are atomic operation, so don’t need to care about concurrence

• Set Expire EXPIRE

  SET resource:lock "Redis Demo"
EXPIRE resource:lock 120 then the key will expire after 120 seconds

  check expire time

  TTL resource:lock will return how many seconds before the key will be deleted

  TTL will return -2 when key not exist

  when key never expires, the TTL will return -1

  when key set expires and set again, it will never be expired

  SET resource:lock "1"

  EXPIRES resource:lock 20

  SET resource:lock "2"

  TTL resource:lock ⇒ -1

• Cancel Expire Time PERSIST

  PERSIST resource:lock

• Combine the SET and EXPIRES together SET xxx EX n

  SET resource:lock "Redis Demo 3" EX 5

• List Operation LPUSH RPUSH LLEN LRANGE LPOP RPOP

  • Put new element at the end of the list RPUSH

    RPUSH friends "Alice"

    RPUSH friends "Bob"

  • Put new element at the start of the list LPUSH

    LPUSH friends "Lucy"

  • Show elements in list LRANGE

    LRANGE friends 0 -1 ⇒ 1) “Lucy” 2) “Alice” 3) “Bob”

  • Pop(means remove from list and return) first element LPOP

    LPOP friends ⇒ “Lucy”

  • Pop last element RPOP

    RPOP friends ⇒ “Bob”

  • Append multiple element RPUSH

    RPUSH friends 1 2 3 ⇒ 1) “Alice” 2) “1” 3) “2” 4) “3”

  • Insert multiple element at the start of the list LPUSH

    LPUSH friends 0 ⇒ 1) 0 2) “Alice” 3) “1” 4) “2” 5) “3”

  • Get Length of the list LLEN

    LLEN friends ⇒ 5

• Set Operation SADD SREM SISMEMBER SMEMBERS SUNION SPOP SRANDMEMBER

  Set does not have a specific order and each element may only appear once.

  • Add one or more element(s) to Set SADD, add an existing element will return 0, otherwise 1

    SADD superpowers "a" "b" "c"

  • Remove one element from Set SREM, will return 0(didn’t remove) or 1(remove success)

    SREM superpowers "a" ⇒1

    SREM superpowers "d" ⇒0 (d doesn’t exist)

  • Test element exist in Set SISMEMBER, will return 0(not exist) or 1(exist)

    SISMEMBER superpowers "b" ⇒ 1

    SISMEMBER superpowers "d" ⇒ 0

  • Return a list including all elements in the Set SMEMBERS

    SMEMBERS superpowers ⇒ 1) “c” 2)“b”

  • Combine two or more sets and return a list of all elements SUNION, element existing in multi sets only return once

    SADD newset 1

    SADD newset 2

    SADD newset "b"

    SUNION newset superpowers ⇒ 1) “c” 2) “1” 3) “b” 4) “2” (order not fixed)

  • Remove and Return 1 or more element(s) from Set SPOP

    Because Set are not ordered, the returned (and removed) elements are totally casual in this case

    SADD letters a b c d e f

    SPOP letters 3 ⇒ e f d(not fixed)

  • Return 1 or more element(s) from Set SRANDMEMBER

    SRANDMEMBER letters 3 ⇒ f c e(not fixed)

• Sorted Set Operation(After Redis v1.2) ZADD ZRANGE

  • Add 1 or more element to Sorted Set ZADD [key] [score] [member]

    ZADD t 2 A

    ZADD t 1 b

    ZRANGE t 0 -1 ⇒ 1) “b” 2) “A”

    if element already exist, then update the score

  • List the element in a sorted Set

    ZRANGE t 0 -1 ⇒ 1) “b” 2) “A”