Redis系列-key相關主要操作函式
阿新 • • 發佈：2019-01-08
這篇blog主要總結下，redis中跟key相關的常用函式
1）keys
語法：keys pattern
解釋：查詢所有匹配指定模式pattern的key
2)randomkey[[email protected] ~]# 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"
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語法：type key
解釋：返回key所儲存的值型別，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
list5）expire
語法：expire key seconds
解釋：設定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不存在或沒有設定生存時間時，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) -18）rename
語法：rename key newkey
解釋：將key改名為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 key9）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) 110）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語法：move key db
解釋：將key移動到指定db
redis 127.0.0.1:6379> smembers stu #預設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"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伺服器來sort大量的資料。可以通過設定閥值減少要sort的資料，或把排序操作向前移，在web伺服器或各個應用上來sort。