Redis的公共操作命令

1.Key操作命令

Redis是Key-Value数据库，Key都是字符串且区分大小写，关于Redis的key操作，主要有常见的以下几个

Redis的命令是不区分大小写的

1.1 keys *

查看当前库所有的Key，类似于数据库的select * from tb_xxx

127.0.0.1:6379> keys *
1) "k1"
2) "k2"

1.2 exists <key]>

Key是否存在，返回bool，1代表true，0代表false

127.0.0.1:6379> exists k1
(integer) 1
127.0.0.1:6379> exists k2
(integer) 1
127.0.0.1:6379> exists k3
(integer) 0

Redis的底层使用C语言实现，很多命令返回bool时，多用0和1表示

1.3 type <key>

key对应的value是什么类型

127.0.0.1:6379> type k1
string

1.4 del <key>

删除数据，返回bool

127.0.0.1:6379> del k2
(integer) 1

1.5 unlink <key>

非阻塞删除，仅仅将key从keyspace元数据中删除，真正的数据删除将在后续异步进行，返回bool

127.0.0.1:6379> unlink k1
(integer) 1

1.6 ttl <key>

查看key还有多少秒过期，-1代表永不过期，-2代表已过期，通常和expire命令搭配使用

127.0.0.1:6379> ttl k1
(integer) -1

1.7 expire <key> <秒数>

为指定的key设置过期时间

127.0.0.1:6379> expire k1 100
(integer) 1
127.0.0.1:6379> ttl k1
(integer) 90
127.0.0.1:6379> ttl k1
(integer) 86

1.8 move <key> <index>

将当前key移动到指定的数据库中，返回bool

127.0.0.1:6379> move k1 2
(integer) 1

2.库操作命令

2.1 select <index>

选中几号仓库。redis.conf配置文件默认Redis共16个数据库(0-15)，默认选中0号库

127.0.0.1:6379> select 2
OK
127.0.0.1:6379[2]> select 3
OK
127.0.0.1:6379[3]> 

2.2 dbsize

查看当前库有多少key

127.0.0.1:6379[3]> dbsize
(integer) 0
127.0.0.1:6379[3]> set k1 v1
OK
127.0.0.1:6379[3]> dbsize
(integer) 1
127.0.0.1:6379[3]> 

2.3 flushdb

清空当前库中的所有key

127.0.0.1:6379> flushdb
OK

2.4 flushall

清空整个Redis中的所有key

127.0.0.1:6379> flushall
OK

3.其他命令

3.1 help @<type>

命令行下输入help @<type>命令，redis服务器会返回该数据类型的所有用法

127.0.0.1:6379> help @string

APPEND key value
summary: Appends a string to the value of a key. Creates the key if it doesn't exist.
since: 2.0.0

DECR key
summary: Decrements the integer value of a key by one. Uses 0 as initial value if the key doesn't exist.
since: 1.0.0

DECRBY key decrement
summary: Decrements a number from the integer value of a key. Uses 0 as initial value if the key doesn't exist.
since: 1.0.0

GET key
summary: Returns the string value of a key.
since: 1.0.0

GETDEL key
summary: Returns the string value of a key after deleting the key.
since: 6.2.0

GETEX key [EX seconds|PX milliseconds|EXAT unix-time-seconds|PXAT unix-time-milliseconds|PERSIST]
summary: Returns the string value of a key after setting its expiration time.
since: 6.2.0

GETRANGE key start end
summary: Returns a substring of the string stored at a key.
since: 2.4.0

GETSET key value
summary: Returns the previous string value of a key after setting it to a new value.
since: 1.0.0

INCR key
summary: Increments the integer value of a key by one. Uses 0 as initial value if the key doesn't exist.
since: 1.0.0

INCRBY key increment
summary: Increments the integer value of a key by a number. Uses 0 as initial value if the key doesn't exist.
since: 1.0.0

INCRBYFLOAT key increment
summary: Increment the floating point value of a key by a number. Uses 0 as initial value if the key doesn't exist.
since: 2.6.0

LCS key1 key2 [LEN] [IDX] [MINMATCHLEN min-match-len] [WITHMATCHLEN]
summary: Finds the longest common substring.
since: 7.0.0

MGET key [key ...]
summary: Atomically returns the string values of one or more keys.
since: 1.0.0

MSET key value [key value ...]
summary: Atomically creates or modifies the string values of one or more keys.
since: 1.0.1

MSETNX key value [key value ...]
summary: Atomically modifies the string values of one or more keys only when all keys don't exist.
since: 1.0.1

PSETEX key milliseconds value
summary: Sets both string value and expiration time in milliseconds of a key. The key is created if it doesn't exist.
since: 2.6.0

SET key value [NX|XX] [GET] [EX seconds|PX milliseconds|EXAT unix-time-seconds|PXAT unix-time-milliseconds|KEEPTTL]
summary: Sets the string value of a key, ignoring its type. The key is created if it doesn't exist.
since: 1.0.0

SETEX key seconds value
summary: Sets the string value and expiration time of a key. Creates the key if it doesn't exist.
since: 2.0.0

SETNX key value
summary: Set the string value of a key only when the key doesn't exist.
since: 1.0.0

SETRANGE key offset value
summary: Overwrites a part of a string value with another by an offset. Creates the key if it doesn't exist.
since: 2.2.0

STRLEN key
summary: Returns the length of a string value.
since: 2.2.0

SUBSTR key start end
summary: Returns a substring from a string value.
since: 1.0.0

127.0.0.1:6379>