05_NoSQL数据库之Redis数据库：Redis的常用命令，键值相关命令和服务器相关命令



Redis常用命令

Redis提供了丰富的命令对数据库和各种数据库类型进行操作，这些命令可以再Linux终端使用。

键值相关命令：

Keys:返回满足给定pattern的所有key

用表达式*表示取出所有的key

127.0.0.1:6379> keys *

1) "age"

2) "name"

3) "age2"

127.0.0.1:6379> keys a*

1) "age"

2) "age2"

127.0.0.1:6379>

Exists:确认一个key是否存在

127.0.0.1:6379> exists name

(integer) 1

127.0.0.1:6379> exists toto

(integer) 0

127.0.0.1:6379>

del:删除一个key.

127.0.0.1:6379> set toto1 toto

OK

127.0.0.1:6379> keys *

1) "name"

2) "age2"

3) "age"

4) "toto1"

127.0.0.1:6379> del toto1  
  //删除toto1这个键。

(integer) 1

127.0.0.1:6379> del toto1  
  //再次删除的时候删除不成功

(integer) 0

127.0.0.1:6379> exists toto1  
//

(integer) 0

127.0.0.1:6379> keys *

1) "name"

2) "age2"

3) "age"

127.0.0.1:6379>

expire:设置一个key的过期时间

在本例中，设置addr这个key的过期时间是10秒，然后不断的用ttl来获取这个key的有效时长，直至-1，说明此值已过期。

expiree addr 10表示：对addr设置过期时间为10秒。

ttl查询剩余的过期时间,当返回-1的时候表示已经过期了。

127.0.0.1:6379> set age 20   
//设置一个key为age的值。

OK

127.0.0.1:6379> get age

"20"

127.0.0.1:6379> expire age 10

(integer) 1

127.0.0.1:6379> ttl age

(integer) 8

127.0.0.1:6379> ttl age

(integer) 5

127.0.0.1:6379> ttl age

(integer) 3

127.0.0.1:6379> ttl age

(integer) -2

127.0.0.1:6379> ttl age

(integer) -2

127.0.0.1:6379> ttl age

(integer) -2

127.0.0.1:6379> exists age

(integer) 0

127.0.0.1:6379> keys *   
//查看age是否还存在

1) "name"

2) "age2"

127.0.0.1:6379>

move:将当前数据库中的key转移到其它数据库中。

选择数据库，要用到select,select 0表示选择到当前数据库。Select
1表示第二个数据库，一共是从0到15个数据库，总共是16个数据库。（注意，进入redis的时候默认进入的是0数据库）

127.0.0.1:6379> select 0

OK

127.0.0.1:6379> set age 30

OK

127.0.0.1:6379> get age

"30"

127.0.0.1:6379> move age 1

(integer) 1

127.0.0.1:6379> get age

(nil)

127.0.0.1:6379> select 1

OK

127.0.0.1:6379[1]> get age

"30"

127.0.0.1:6379[1]>

persist:移除给定key的过期时间

127.0.0.1:6379[1]> select 1

OK

127.0.0.1:6379[1]> keys *

1) "age"

127.0.0.1:6379[1]> expire age 300

(integer) 1

127.0.0.1:6379[1]> ttl age

(integer) 297

127.0.0.1:6379[1]> ttl age

(integer) 293

127.0.0.1:6379[1]> persist age  
 //取消age的过期

(integer) 1

127.0.0.1:6379[1]> ttl age

(integer) -1

127.0.0.1:6379[1]> exists age

(integer) 1

127.0.0.1:6379[1]> keys *

1) "age"

127.0.0.1:6379[1]>

randomkey:随机返回key空间的一个key

127.0.0.1:6379[1]> keys *

1) "gender"

2) "name"

3) "address"

4) "age"

127.0.0.1:6379[1]> randomkey      
//随机获得一个key

"gender"

127.0.0.1:6379[1]> randomkey

"address"

127.0.0.1:6379[1]> randomkey

"gender"

127.0.0.1:6379[1]>

rename:重命名key

127.0.0.1:6379[1]> keys *

1) "gender"

2) "name"

3) "address"

4) "age"

127.0.0.1:6379[1]>
rename age nianling    将age这个key重新命名为nianling

OK

127.0.0.1:6379[1]> keys *

1) "gender"

2) "name"

3) "address"

4) "nianling"

127.0.0.1:6379[1]>

type:返回键的数据类型

127.0.0.1:6379[1]> type name

string

127.0.0.1:6379[1]>

服务器的相关命令

ping:测试连接是否存活

echo:在命令行打印一些内容

127.0.0.1:6379> echo toto

"toto"

127.0.0.1:6379> echo toto2

"toto2"

select:选择数据库.Redis数据库编号从0~15，我们可以选择任意一个数据库来进行数据的存取。

当选择16时，报错，说明没有编号为16的这个数据库。

quit:退出连接，或者exit

dbsize:返回当前数据库中key的数目。

127.0.0.1:6379> keys *

1) "age2"

2) "name"

127.0.0.1:6379> dbsize

(integer) 2               
//返回0表示有2个key

127.0.0.1:6379> select 1

OK

127.0.0.1:6379[1]> keys *

1) "gender"

2) "name"

3) "address"

4) "nianling"

127.0.0.1:6379[1]> dbsize

(integer) 4                
//返回4表示有4个key

127.0.0.1:6379[1]>

info:获取服务器的信息和统计

127.0.0.1:6379[1]> info

# Server

redis_version:2.8.19

redis_git_sha1:00000000

redis_git_dirty:0

redis_build_id:b80fb73838c77f5a

redis_mode:standalone

os:Linux 2.6.32-358.el6.x86_64 x86_64

arch_bits:64

multiplexing_api:epoll

gcc_version:4.4.7

process_id:5136

run_id:607e299bec2e4e492d138ee1a5a29871d0062e24

tcp_port:6379

uptime_in_seconds:2863

uptime_in_days:0

hz:10

lru_clock:14609760

config_file:

# Clients

connected_clients:1

client_longest_output_list:0

client_biggest_input_buf:0

blocked_clients:0

# Memory

used_memory:504152

used_memory_human:492.34K

used_memory_rss:7958528

used_memory_peak:504152

used_memory_peak_human:492.34K

used_memory_lua:35840

mem_fragmentation_ratio:15.79

mem_allocator:jemalloc-3.6.0

# Persistence

loading:0

rdb_changes_since_last_save:8

rdb_bgsave_in_progress:0

rdb_last_save_time:1423893041

rdb_last_bgsave_status:ok

rdb_last_bgsave_time_sec:-1

rdb_current_bgsave_time_sec:-1

aof_enabled:0

aof_rewrite_in_progress:0

aof_rewrite_scheduled:0

aof_last_rewrite_time_sec:-1

aof_current_rewrite_time_sec:-1

aof_last_bgrewrite_status:ok

aof_last_write_status:ok

# Stats

total_connections_received:1

total_commands_processed:40

instantaneous_ops_per_sec:0

total_net_input_bytes:969

total_net_output_bytes:584

instantaneous_input_kbps:0.00

instantaneous_output_kbps:0.00

rejected_connections:0

sync_full:0

sync_partial_ok:0

sync_partial_err:0

expired_keys:0

evicted_keys:0

keyspace_hits:7

keyspace_misses:1

pubsub_channels:0

pubsub_patterns:0

latest_fork_usec:0

# Replication

role:master

connected_slaves:0

master_repl_offset:0

repl_backlog_active:0

repl_backlog_size:1048576

repl_backlog_first_byte_offset:0

repl_backlog_histlen:0

# CPU

used_cpu_sys:3.51

used_cpu_user:0.93

used_cpu_sys_children:0.00

used_cpu_user_children:0.00

# Keyspace

db0:keys=2,expires=0,avg_ttl=0

db1:keys=4,expires=0,avg_ttl=0

127.0.0.1:6379[1]>

config get:实时传储收到的请求。

127.0.0.1:6379[1]> config get *

1) "dbfilename"

2) "dump.rdb"

3) "requirepass"

4) ""

5) "masterauth"

6) ""

7) "unixsocket"

8) ""

9) "logfile"

10) ""

11) "pidfile"

12) "/var/run/redis.pid"

13) "maxmemory"

14) "0"

15) "maxmemory-samples"

16) "3"

17) "timeout"

18) "0"

19) "tcp-keepalive"

20) "0"

21) "auto-aof-rewrite-percentage"

22) "100"

23) "auto-aof-rewrite-min-size"

24) "67108864"

25) "hash-max-ziplist-entries"

26) "512"

27) "hash-max-ziplist-value"

28) "64"

29) "list-max-ziplist-entries"

30) "512"

31) "list-max-ziplist-value"

32) "64"

33) "set-max-intset-entries"

34) "512"

35) "zset-max-ziplist-entries"

36) "128"

37) "zset-max-ziplist-value"

38) "64"

39) "hll-sparse-max-bytes"

40) "3000"

41) "lua-time-limit"

42) "5000"

43) "slowlog-log-slower-than"

44) "10000"

45) "latency-monitor-threshold"

46) "0"

47) "slowlog-max-len"

48) "128"

49) "port"

50) "6379"

51) "tcp-backlog"

52) "511"

53) "databases"

54) "16"

55) "repl-ping-slave-period"

56) "10"

57) "repl-timeout"

58) "60"

59) "repl-backlog-size"

60) "1048576"

61) "repl-backlog-ttl"

62) "3600"

63) "maxclients"

64) "4064"

65) "watchdog-period"

66) "0"

67) "slave-priority"

68) "100"

69) "min-slaves-to-write"

70) "0"

71) "min-slaves-max-lag"

72) "10"

73) "hz"

74) "10"

75) "repl-diskless-sync-delay"

76) "5"

77) "no-appendfsync-on-rewrite"

78) "no"

79) "slave-serve-stale-data"

80) "yes"

81) "slave-read-only"

82) "yes"

83) "stop-writes-on-bgsave-error"

84) "yes"

85) "daemonize"

86) "no"

87) "rdbcompression"

88) "yes"

89) "rdbchecksum"

90) "yes"

91) "activerehashing"

92) "yes"

93) "repl-disable-tcp-nodelay"

94) "no"

95) "repl-diskless-sync"

96) "no"

97) "aof-rewrite-incremental-fsync"

98) "yes"

99) "aof-load-truncated"

100) "yes"

101) "appendonly"

102) "no"

103) "dir"

104) "/usr/local/redis/bin"

105) "maxmemory-policy"

106) "volatile-lru"

107) "appendfsync"

108) "everysec"

109) "save"

110) "3600 1 300 100 60 10000"

111) "loglevel"

112) "notice"

113) "client-output-buffer-limit"

114) "normal 0 0 0 slave 268435456 67108864 60 pubsub 33554432 8388608 60"

115) "unixsocketperm"

116) "0"

117) "slaveof"

118) ""

119) "notify-keyspace-events"

120) ""

121) "bind"

122) ""

127.0.0.1:6379[1]>

127.0.0.1:6379[1]> config get timeout

1) "timeout"

2) "0"

127.0.0.1:6379[1]>

flushdb:删除当前选择数据库中的所有key（也就是说flushdb的作用是清空当前数据库）

127.0.0.1:6379[2]> select 1

OK

127.0.0.1:6379[1]> set age 20

OK

127.0.0.1:6379[1]> set name zhangsan

OK

127.0.0.1:6379[1]> set gender male

OK

127.0.0.1:6379[1]> keys *

1) "name"

2) "gender"

3) "age"

127.0.0.1:6379[1]> flushdb

OK

127.0.0.1:6379[1]> keys *

(empty list or set)

127.0.0.1:6379[1]>

flushall:删除所有数据库中的所有key(这个命令不管你在哪个数据库中执行，都会把所有数据库中的所有key都删除掉)。

127.0.0.1:6379[1]> select 0

OK

127.0.0.1:6379> dbsize

(integer) 3

127.0.0.1:6379> keys *

1) "name"

2) "age"

3) "age2"

127.0.0.1:6379> select 1

OK

127.0.0.1:6379[1]> keys *

(empty list or set)

127.0.0.1:6379[1]> set age 1

OK

127.0.0.1:6379[1]> set name zhangsan     
左侧用来确定0
和 1
数据库是否有key

OK

127.0.0.1:6379[1]> keys *

1) "name"

2) "age"

127.0.0.1:6379[1]> dbsize

(integer) 2

127.0.0.1:6379[1]> flushall         
数据库都变成空了

OK

127.0.0.1:6379[1]> keys *

(empty list or set)

127.0.0.1:6379[1]> select 0

OK

127.0.0.1:6379> keys *

(empty list or set)

127.0.0.1:6379>