String type and operation of Redis
set: Set the value corresponding to key to string type value.
127.0.0.1:6379> set name stone
OK
127.0.0.1:6379> get name
"stone"
127.0.0.1:6379> set name stone1
OK
127.0.0.1:6379> get name
"stone1"
setnx: Set the value corresponding to key to string type value, if the key already exists, return 0, nx means not exist.
127.0.0.1:6379> get name
"stone1"
127.0.0.1:6379> setnx name stone
(integer) 0
127.0.0.1:6379> get name
"stone1"
setex: Set the value corresponding to key to string type value, and specify the validity period corresponding to this key value.
127.0.0.1:6379> setex haircolor 10 red
OK
127.0.0.1:6379> get haircolor
"red"
127.0.0.1:6379> get haircolor
(nil)
setrang: A substring that sets the value of the specified key.
127.0.0.1:6379> set email stone@163.com
OK
127.0.0.1:6379> setrange email 6 qq.com
(integer) 13
127.0.0.1:6379> get email
"stone@qq.comm"
mset: Set multiple key values at once, success returns ok means all values are set, failure returns 0 means none is set.
127.0.0.1:6379> mset key1 stone1 key2 stone2
OK
127.0.0.1:6379> get key1
"stone1"
127.0.0.1:6379> get key2
"stone2"
msetnx: Set multiple key values at once, success returns ok means all values are set, failure returns 0 means no values are set, but does not overwrite existing keys.
127.0.0.1:6379> msetnx key1 s1 key2 s2 key3 ston3
(integer) 0
127.0.0.1:6379> get key1
"stone1"
127.0.0.1:6379> get key2
"stone2"
127.0.0.1:6379> get key3
(nil)
127.0.0.1:6379> msetnx key3 stone3 key4 stone4
(integer) 1
127.0.0.1:6379> get key3
"stone3"
127.0.0.1:6379> get key4
"stone4"
get: Get the string value corresponding to the key, if the key does not exist, return nil.
getset: Sets the value of key and returns the old value of key.
127.0.0.1:6379> get key4
"stone4"
127.0.0.1:6379> getset key4 stone44
"stone4"
127.0.0.1:6379> get key4
"stone44"
getrange: Gets the substring of the value of key.
127.0.0.1:6379> get key4
"stone44"
127.0.0.1:6379> getrange key4 0 1
"st"
127.0.0.1:6379> getrange key4 0 0
"s"
mget: Get multiple key values at once. If the corresponding key does not exist, nil will be returned.
127.0.0.1:6379> mget key1 key2 key3 key4 key5
1) "stone1"
2) "stone2"
3) "stone3"
4) "stone44"
5) (nil)
incr: Adds the value of key and returns the new value.
incrby: similar to incr, add the specified value, key will be set when it does not exist, and think that the original value is 0.
127.0.0.1:6379> set num1 10
OK
127.0.0.1:6379> incr num1
(integer) 11
127.0.0.1:6379> get num1
"11"
127.0.0.1:6379> get num2
(nil)
127.0.0.1:6379> incrby num2 2
(integer) 2
127.0.0.1:6379> incrby num2 2
(integer) 4
127.0.0.1:6379> get num2
"4"
Decr: Subtract or subtract the value of key.
Decrby: Similar to decr, minus the specified value.
127.0.0.1:6379> get num1
"11"
127.0.0.1:6379> decr num1
(integer) 10
127.0.0.1:6379> get num1
"10"
127.0.0.1:6379> get num2
"4"
127.0.0.1:6379> decrby num2 2
(integer) 2
127.0.0.1:6379> get num2
"2"
append: appends value to the string of the specified key and returns the length of the new string value.
127.0.0.1:6379> get name
"stone1"
127.0.0.1:6379> append name @qq.com
(integer) 13
127.0.0.1:6379> get name
"stone1@qq.com"
strlen: Takes the length of the value of the specified key.
127.0.0.1:6379> strlen name
(integer) 13
