Simple introduction of five types of redis commonly used in the data

1.string

The string in Redis is a sequence of bytes. The strings in Redis are binary safe, meaning that their lengths are not determined by any particular terminating character. As a result, you can store anything up to 512 megabytes in a string.

There is a set get Operation command that is case-insensitive

2.hash

a Redis hash/hash (hashes) is a collection of key-value pairs. it provides a mapping of field and field values. Field values can only be string types, and other types such as hash type, collection type, and so on are not supported.

assignment Syntax: Hset key field value
Set a field value,The Hset command does not differentiate between insert and update operations, and when an insert operation is performed, the Hset command returns 1, which returns 0 when the update operation is performed.
Value syntax: Hget key field
Set multiple field syntax: Hmset key field value [field value ...]
Take multiple value syntax: Hmget key field [field ...]
Get all field value syntax: Hgetall key
Delete field syntax: Hdel key field [field ...]
Ex:hmset items1 ID 3 name Apple price 99
3.listRedis list is used to store the linked list, two-way linked lists to store data, features: Quick additions and deletions, slow query (LinkedList)
add element to the left of the list: Lpush key value [value ...]
Eject element from left of list: Lpop key
Add elements to the right of the list: Rpush key value [value ...]
Eject element from right of list: Rpop key
To get the number of elements in a list: Llen key
View list syntax: Lrange key start stop
All of the elements between start and stop (containing elements at both ends) are returned, and the index starts at 0 and can be negative, such as: "-1" represents the last element.

4.set and ZsetSet collection type: unordered, not repeatable
add element syntax: Sadd key member [member ...]
Delete element syntax: Srem key member [member ...]
Get all the elements in the collection: Smembers key
To determine whether an element is in the collection: Sismember Key member
SortedSet, also called Zset, is an ordered set, sortable, but unique. The difference between SortedSet and set is to add a fraction to the elements in the set and then sort by that fraction.
add element: Zadd key score member [score ...]
Adds an element and a fraction of the element to an ordered set, and replaces the original score with the new fraction if the element already exists.
Get a list of elements in a range Zrange key start stop [withscores] returns in order of element fractions from small to large
Return in order of element fractions from large to small
Syntax: Zrevrange key start stop [Withscores]
Get score of element: Zscore Key Member
Delete element Zrem key member [...]
The score of the element can be obtained by adding the Withscores parameter at the end of the command
Application: Sale of Goods
Product number 1001 Sales is 9, the product number 1002 sales are 10
Zadd Sellsort 9 1001 10 1002
Product number 1001 Sales plus 1:zincrby sellsort 1 1001
Product Sales ranking top 3 in the queue:
Zrevrange Sellsort 0 2 withscores