Type String

1. Memory storage model

2. Common operation commands

The command instructions
set Set a key/value
get Obtain the corresponding value based on the key
mset Set multiple keys and values at a time
mget Get multiple key values at once
getset Gets the value of the original key and sets the new value
strlen Get the length of the value stored by the corresponding key
append Appends the value of the corresponding key
Getrange index 0 starts Intercepts the contents of value
setex Set the lifetime of a key in seconds
psetex Set the lifetime of a key in milliseconds
setnx Exists No operation is performed, and no addition is performed
Msetnx atom operation (as long as there is one does nothing) Multiple keys can be set at the same time
decr Performs a -1 operation of numeric type
decrby Perform subtraction operations based on the data provided
incr Perform a +1 operation of numeric type
incrby Add based on the supplied data
incrbyfloat Add floating point numbers based on supplied data

List the type

List A list is equivalent to a list set in Java. It is ordered and repeatable

Memory storage model

Common operation instruction

The command instructions
lpush Adds a value to the head of a key list
lpushx Same as push, but you have to make sure that this key exists
rpush Adds a value to the end of a key list
rpushx Same as Rpush, but you have to make sure that this key exists
lpop Returns and removes the first element on the left of the list
rpop Returns and removes the first element to the right of the list
lrange Getting the elements in one of the following table ranges can be used for paging
llen Gets the number of list elements
lset Sets the value of a specified index (so it must exist)
lindex Gets the element at a specified index position
lrem Delete duplicate elements
ltrim Keep elements within a specific range of the list
linsert Inserts a new element before or after an element

The Set type

Characteristic: disorder cannot repeat

Memory storage model

Common commands

The command instructions
sadd Add elements to the collection
smembers Displays all elements in the collection out of order
scard Returns the number of elements in the collection
spop Returns a random element and deletes it from the collection
smove Moving elements from one collection to another must be of the same type
srem Removes an element from the collection
sismember Determines whether a collection contains this element
srandmember Random return element
sdiff Remove the same elements from the first set in other sets
sinter masked
sunion For collection

ZSet type

Features: sortable set set, sorting is not repeatable

Memory storage model

Common commands

The command instructions
zadd Add an ordered collection element
zcard Returns the number of elements in the collection
Zrange ascending Zrevrange descending Returns a range of elements
zrangebyscore Find elements in a range by score
zrank Return to top
zrevrank List in reverse chronological order
zscore Displays the score of an element
zrem Remove an element
zincrby Give credit to a particular element

Hash type

Features: Value is a map structure with keys and values, but keys are unordered

Memory storage model

Common commands

The command instructions
hset Set a key/value
hget Get a value for a key
hgetall Get all key/value pairs
hdel Example Delete a key or value
hexists Check whether a key exists
hkeys Get all the keys
hvals Get all values
hmset Set multiple keys and values
hmget Get multiple keys/values
hsetnx Set the value of a key that does not exist
hincrby Value must be of numeric type
hincrbyfloat Adds a floating point value to value