Redis five data types, String, hash, list, set, ordered set
The following commands are common to these five data types (6 common commands)
- keys pattern : Get all keys matching pattern. * means any one or more characters; ? represents a character
For example: now there is
key value
name zhaowei
list1 [a b c d]
set1 [e m n d]
username zhaowei
Requirement 1: Find all keys that contain name
Command: keys *name*
Requirement 2: Find the four-character key
Command: keys ????
Requirement 3: Query all keys
Command: keys *
- del key1 key2..... delete key
Requirement: delete username and name
Command: del username name
- The exists key judges whether a key exists, 1 means exists, 0 means does not exist
Requirement: determine whether list1 exists
Command: exists list1
- rename key newkey renames the current key (this is rarely used in development, but you need to know)
- type key Gets the type of the specified key. The command will return in string format. The returned string is String, hash, list, set, zset, if the key does not exist, return none
Set the validity period of the key
- expire key time (in seconds) : set the lifetime of the key
- ttl key : Get the remaining time to live for the key
You can see that when list2 expires, it returns -2, and redis will delete the expired key
The ttl permanent key value is -1, which means it can live forever