(Redis): Redis general instructions

table of Contents

Redis general instructions

key basic operation

Key expansion operation (timeliness control)

Key extended operation (query mode)

key other operations 

Database general instructions

db basic operation

db related operations

Redis general instructions

key feature

• The key is a string, and the data saved in redis is obtained through the key

What operations should the key design?

• Operations related to the state of the key itself, such as deleting, determining existence, obtaining type, etc.
• For key validity control related operations, such as: valid period setting, judging whether it is valid, switching of valid status, etc.
• For quick key query operation, for example: query key according to specified strategy
• ……

key basic operation

Delete the specified key	of the key
Get whether the key exists	exists key
Get the type of key	type key

Key expansion operation (timeliness control)

Set the validity period for the specified key	expire key seconds pexpire key milliseconds expireat key timestamp pexpireat key milliseconds-timestamp
Get the effective time of the key	ttl key pttl key
Switch the key from time-sensitive to permanent	persist key

Key extended operation (query mode)

• Query key

keys pattern

• Query mode rules

*	Match any number of any symbols
?	With an arbitrary symbol
[ ]	Matches a specified symbol

keys *	Query all
keys it*	Query all beginning with it
keys * at home	Query all ending with heima
keys at home	Query all the first two characters are arbitrary, and the back ends with heima
keys user:?	Query all starting with user: and any last character
keys u[st]er:1	Query all starting with u, ending with er:1, containing a letter, s or t

key other operations 

Rename the key	rename key newkey renamenx key newkey
Sort all keys	sort
Other key common operations	help @generic

Database general instructions

Key duplication problem

• key is defined by the programmer
• During the use of redis, with the increase in the amount of operating data, a large amount of data and corresponding keys will appear
• The data does not distinguish between types, and the categories are mixed together, and it is easy to repeat or conflict

solution

• redis provides 16 databases for each service , numbered from 0 to 15
• Data between each database is independent of each other

db basic operation

Switch database	select index
Other operations	quit ping echo message

db related operations

Data movement	move key db
Data clear	dbsize flushdb flushall

• [Note]: Refer to the Dark Horse Redis tutorial: https://www.bilibili.com/video/BV1AE411j7Wq?t=5