Redis Note5:Redis-Key—String

1. String

1.1 追加：append

# 追加 append ，如果没有添加，相当于set
127.0.0.1:6379[3]> APPEND name "Hello"
(integer) 12
127.0.0.1:6379[3]> get name
"henggaoHello"

# 获取字符串长度STRLEN 
127.0.0.1:6379[3]> STRLEN name
(integer) 12

127.0.0.1:6379[3]> append sex "male"
(integer) 4
127.0.0.1:6379[3]> keys *
1) "age"
2) "sex"
3) "name"

1.2 自增自减：INCR 、DECR 、INCRBY 、DECRBY

127.0.0.1:6379[3]> set views 0
OK
# 自增1 INCR 
127.0.0.1:6379[3]> INCR views
(integer) 1
127.0.0.1:6379[3]> INCR views
(integer) 2
127.0.0.1:6379[3]> get views
"2"
# 自减1 DECR 
127.0.0.1:6379[3]> DECR views
(integer) 1
127.0.0.1:6379[3]> get views
"1"
# 设置长，增张量INCRBY 
127.0.0.1:6379[3]> INCRBY views 10
(integer) 11
127.0.0.1:6379[3]> get views
"11"
# 减量INCRBY 
127.0.0.1:6379[3]> DECRBY views 5
(integer) 6
127.0.0.1:6379[3]> get views
"6"

1.3 字符串范围：GETRANGE

127.0.0.1:6379[3]> set key1 "hello,henggao"
OK
127.0.0.1:6379[3]> get key1
"hello,henggao"
# 字符串范围，截取字符串【0，3】
127.0.0.1:6379[3]> GETRANGE key1 0 3
"hell"
# 全部字符串
127.0.0.1:6379[3]> GETRANGE key1 0 -1
"hello,henggao"

1.4 替换：setrange

127.0.0.1:6379[3]> get key2
"abcdef"
127.0.0.1:6379[3]> setrange key2 1 xx
(integer) 6
127.0.0.1:6379[3]> get key2
"axxdef"

1.5 设置过期时间：setex

# 设置key3的值为hello，30s后过期
127.0.0.1:6379[3]> setex key3 30 "hello"
OK
127.0.0.1:6379[3]> ttl key3
(integer) 24
127.0.0.1:6379[3]> ttl key3
(integer) 14
127.0.0.1:6379[3]>

1.6 设置存在与不存在：setenx

# 如果不存在key4，创建key4
127.0.0.1:6379[3]> setnx key4 "redis"
(integer) 1
# 如果存在key4，创建失败
127.0.0.1:6379[3]> setnx key4 "mongodb"
(integer) 0
127.0.0.1:6379[3]> get key4
"redis"
127.0.0.1:6379[3]>

1.7 设置、获取多个值：mset 、mget

127.0.0.1:6379[3]> mset k1 v1 k2 v2 k3 v3
OK
127.0.0.1:6379[3]> keys *
1) "k2"
2) "k3"
3) "k1"
127.0.0.1:6379[3]> mget k1 k2 k3
1) "v1"
2) "v2"
3) "v3"

1.8 设置对象

# set user:1{name:zhangsan,age:23} 

127.0.0.1:6379[3]> mset user:1:name zhangsan user:1:age 23
OK
127.0.0.1:6379[3]> mget user:1:name user:1:age
1) "zhangsan"
2) "23"
127.0.0.1

1.9 先获取在设置getset

# 不存在的值，返回nil
127.0.0.1:6379[3]> getset db redis
(nil)
# 如果存在，获取原来值，并设置新的值
127.0.0.1:6379[3]> getset db mongodb
"redis"
127.0.0.1:6379[3]> get db
"mongodb"