這篇blog主要總結下,redis中跟key相關的常用函數
1)keys
語法:keys pattern
解釋:查找所有匹配指定模式pattern的key
[root@xsf001 ~]# redis-cli
redis 127.0.0.1:6379> keys * #所有key
1) "score"
2) "stu"
3) "score1"
4) "dest"
5) "lst.user"
6) "lst.tect"
redis 127.0.0.1:6379> keys scor?
1) "score"
redis 127.0.0.1:6379> keys scor[ee1]
1) "score"
2)randomkey
語法:randomkey
解釋:返回一個隨機key
redis 127.0.0.1:6379> randomkey
"score"
redis 127.0.0.1:6379> randomkey
"list.user"
3)exists
語法:exists key
解釋:判斷一個key是否存在
redis 127.0.0.1:6379> exists score #key存在 返回1
(integer) 1
redis 127.0.0.1:6379> exists scorefda #key不存在 返回0
(integer) 0
4)type
語法:type key
解釋:返回key所存儲的值類型,返回值:none【key不存在】,string,list ,set, zset和hash
redis 127.0.0.1:6379> type score
zset
redis 127.0.0.1:6379> type lst.user
list
5)expire
語法:expire key seconds
解釋:設置key的生存時間,單位是秒,當key過期時,會被自動刪除
redis 127.0.0.1:6379> expire dest 30
(integer) 1
redis 127.0.0.1:6379> expire dest1 30 # key不存在
(integer) 0
6)ttl
語法: ttl key
解釋:得到key能存活時間,如果key不存在或沒有設置生存時間時,返回-1
redis 127.0.0.1:6379> expire diff 100
(integer) 1
redis 127.0.0.1:6379> ttl diff
(integer) 94
redis 127.0.0.1:6379> ttl diff
(integer) 92
7)persist
語法:persist key
解釋:移除給定key的生存時間
redis 127.0.0.1:6379> ttl diff
(integer) 28
redis 127.0.0.1:6379> persist diff
(integer) 1
redis 127.0.0.1:6379> ttl diff
(integer) -1
8)rename
語法:rename key newkey
解釋:將key改名爲newkey
redis 127.0.0.1:6379> smembers diff
1) "zhangsan01"
redis 127.0.0.1:6379> rename diff diff01
OK
redis 127.0.0.1:6379> smembers diff
(empty list or set)
redis 127.0.0.1:6379> smembers diff01
1) "zhangsan01"
redis 127.0.0.1:6379> rename diff diff01
(error) ERR no such key
注意:當key和newkey相同或key不存在時,返回錯誤;當newkey已存在時,rename將覆蓋舊值。
9)renamenx
語法:renamenx key newkey
解釋:當且僅當newkey不存在時,改名key
redis 127.0.0.1:6379> renamenx diff01 stu #stu存在
(integer) 0
redis 127.0.0.1:6379> renamenx diff01 diff #diff不存在
(integer) 1
10)del
語法:del key [key ...]
解釋:刪除一個或多個key
redis 127.0.0.1:6379> del score1
(integer) 1
redis 127.0.0.1:6379> del union diff aa #key aa 不存在
(integer) 2
11)move
語法:move key db
解釋:將key移動到指定db
redis 127.0.0.1:6379> smembers stu #默認0
1) "zhangsan01"
2) "wangwu"
redis 127.0.0.1:6379> move stu 1 #移動到 1
(integer) 1
redis 127.0.0.1:6379> smembers stu
(empty list or set)
redis 127.0.0.1:6379> select 1 #選擇db 1
OK
redis 127.0.0.1:6379[1]> smembers stu
1) "zhangsan01"
2) "wangwu"
12)sort
語法:sort key [BY pattern] [LIMIT offset count] [GET pattern [GET pattern ...]] [ASC|DESC] [ALPHA] [STORE destination]
解釋:返回或保持給定列表,集合,有序集合key中經過排序的元素
redis 127.0.0.1:6379> sort lst.tech limit 0 2 alpha desc #按字符集排序
1) "tec06"
2) "tec05"
redis 127.0.0.1:6379> sort lst.stud
1) "1"
2) "2"
3) "3"
redis 127.0.0.1:6379> sort lst.stud desc
1) "3"
2) "2"
3) "1"
redis 127.0.0.1:6379> keys stu.*
1) "stu.name.2"
2) "stu.name.3"
3) "stu.level.1"
4) "stu.level.2"
5) "stu.level.3"
6) "stu.name.1"
redis 127.0.0.1:6379> sort lst.stud by stu.level.* desc get stu.level.* get stu.name.*
1) "3"
2) "admin"
3) "2"
4) "joe"
5) "1"
6) "jim"
redis 127.0.0.1:6379> sort lst.stud by stu.level.* asc get stu.name.*
1) "jim"
2) "joe"
3) "admin"
sort雖然很“厲害”,但儘量不要讓redis服務器來sort大量的數據。可以通過設定閥值減少要sort的數據,或把排序操作向前移,在web服務器或各個應用上來sort。