Shulou(Shulou.com)06/01 Report--

Click "official" to view commands file http://redis.cn/commands.htmlRedis command operation: http://doc.redisfans.com/ data structure

Redis is the data structure of key-value. Each piece of data is a pair of keys and values.

The type of key is a string

Note: keys cannot be repeated

There are five types of values:

String string

Hash hash

List list

Set set

Ordered set zset

Data manipulation behavior

Save

Modify

Get

Delete

Click the "official" to view the commands file http://redis.cn/commands.html

RDB error reporting and its solution

MISCONF Redis is configured to save RDB snapshots, but is currently not able to persist on disk. Commands that may modify the data set are disabled. Please check Redis logs for details about the error.

Redis is configured to hold database snapshots, but it cannot be persisted to the hard disk at this time. The command used to modify collection data cannot be used

Reason:

Force closing Redis snapshots so that they cannot be persisted. Solution:

After running the config set stop-writes-on-bgsave-error no command, close the configuration item stop-writes-on-bgsave-error to resolve the problem.

Key command

Find key, parameter hold regular expression

Keys pattern

Example 1: view all keys

Keys *

Example 2: view the key containing an in the name

Keys' aura'

Determine whether the key exists. If it exists, it returns 1, and 0 does not exist.

Exists key1

Example 3: judge whether the key A1 exists

Exists a1

Check the type of value corresponding to the key

Type key

Example 4: check the value type of key A1, which is one of the five types held by redis

Type a1

Delete keys and corresponding values

Del key1 key2...

Example 5: delete keys a2 and A3

Del a2 a3

Sets the expiration time in seconds

If no expiration time is specified, it will exist until the expiration DEL is removed.

Expire key seconds

Example 6: the expiration time of the setting key'A1'is 3 seconds

Expire 'a1' 3

View valid time in seconds

Ttl key

Example 7: check the validity time of the key 'bb'

Ttl bb

String Typ

String type is the most basic data storage type in Redis, and it is binary safe in Redis, which means that this type can accept data in any format, such as JPEG image data or Json object description information. The maximum length of data that a string type Value can hold in Redis is 512m.

Save

Add if the set key does not exist, or modify it if the set key already exists

Set key value

Set key value

Example 1: set the key to the data whose name value is itcast

Set name itcast

Set key value and expiration time in seconds

Setex key seconds value

Example 2: set key to data with AA value and aa expiration time of 3 seconds

Setex aa 3 aa

Set multiple key values

Mset key1 value1 key2 value2...

Example 3: set key to'A1', value to 'python', key to' a2', value to 'java', key to' A3', value to'c'

Mset a1 python a2 java a3 c

Added value

Append key value

Example 4: add the value '' to A1

Append 'a1' '

Get

Get: get the value according to the key, and return nil if the key does not exist

Get key

Example 5: get the value of the key 'name'

Get 'name'

Get multiple values based on multiple keys

Mget key1 key2...

Example 6: get the values of keys A1, a2, a3'

Mget a1 a2 a3

Delete

The value is deleted when the key is deleted

Hash Typ

Hash stores objects, whose structure is attributes and values.

The value is of type string

Add, modify

Set a single property

Hset key field value

Example 1: set the property name of the key user to libai

Hset user name libai

Set multiple properties

Hmset key field1 value1 field2 value2...

Example 2: set key U2's attribute name is itcast, attribute age is 11

Hmset u2 name laowang age 11

Get

Gets all the properties of the specified key

Hkeys key

Example 3: get all the attributes of key U2

Hkeys u2

Get the values of several attributes

Hget key field

Example 4: get the value of the key U2 attribute 'name'

Hget U2 'name'

Get the values of multiple attributes

Hmget key field1 field2...

Example 5: get the value of the key U2 attribute 'name',' age

Hmget u2 name age

Get the values of all attributes

Hvals key

Example 6: get the values of all attributes of the key 'U2'

Hvals u2

List Typ

The element type of the list is string

Sort by insertion order

Increase

Insert data on the left

Lpush key value1 value2...

Example 1: add additional data a, b, c from the left side of the list with key'A1'

Lpush a1 a b c

Insert data on the right

Rpush key value1 value2...

Example 2: add data 0 1 from the right side of the list with key'A1'

Rpush a1 0 1

Inserts a new element before or after the specified element

Linsert key before or after existing elements new elements

Example 3: add'3' before element'b' in the list with key'A1'.

Linsert a1 before b 3

Get

Returns the list of elements within the specified range

Lrange key start stop

Start and stop are the subscript indexes of the element

The index starts on the left, and the first element is 0

The index can be negative, indicating that the count starts at the tail, such as-1 for the last element

Example 4: get all the elements of the list with the key'A1'

Lrange a1 0-1

Sets the element value at the specified index location

The index starts on the left, and the first element is 0

The index can be negative, indicating the start of the tail count, such as-1 for the last element

Lset key index value

Example 5: the value of the element with subscript 1 in the list with the modification key'A1'is'z'.

Lset a 1 z

Delete

Delete the specified element

Lrem key count value

Remove the element whose value is value in the previous count occurrence in the list

Count > 0: remove from beginning to end

Count < 0: remove from tail to head

Count = 0: remove all

Example 6.1: add additional elements'a','b','a','b','a','b'to the list 'a2'

Lpush a2 a b a b a b

Example 6.2: delete 2'b' from the right side of the'a2 'list

Lrem a2-2 b

Example 6.3: view all the elements of the list 'py12'

Lrange a2 0-1

Set Typ

Ordered set

Element is of type string

Elements are unique and do not repeat.

Description: no modification operation for the collection

Increase

Add element

Sadd key member1 member2...

Example 1: add elements' zhangsan', 'lisi',' wangwu' to the collection of key 'A3'

Sadd a3 zhangsan sili wangwu

Get

Return all elements

Smembers key

Example 2: get all the elements in the collection of the key 'A3'

Smembers a3

Delete

Delete the specified element

Srem key

Example 3: delete the element 'wangwu' from the collection of key' A3'

Srem a3 wangwu

Zset Typ

Sorted set, ordered set

Element is of type string

Elements are unique and do not repeat.

Each element is associated with a score of type double, which represents weight, and elements are sorted from "to" by weight.

Description: no modification operation

Increase

Add

Zadd key score1 member1 score2 member2...

Example 1: adding elements' lisi', 'wangwu',' zhaoliu' and 'zhangsan', to the collection of key' a4' has weights of 4, 5, 6 and 3, respectively

Zadd a4 4 lisi 5 wangwu 6 zhaoliu 3 zhangsan

Get

Returns elements within the specified range

Start and stop are the subscript indexes of the element

The index starts on the left, and the first element is 0

The index can be negative, indicating that the count starts at the tail, such as-1 for the last element

Zrange key start stop

Example 2: get all the elements in the collection of the key 'a4'

Zrange a4 0-1

Returns the member whose score value is between min and max

Zrangebyscore key min max

Example 3: get members with permission values between 5 and 6 in the collection of key 'a4'

Zrangebyscore a4 5 6

Returns the score value of the member member

Zscore key member

Example 4: get the weight of the element 'zhangsan' in the collection of key' a4'

Zscore a4 zhangsan

Delete

Delete the specified element

Zrem key member1 member2...

Example 5: delete the element 'zhangsan' in the collection' a4'

Zrem a4 zhangsan

Delete elements with weights in the specified range

Zremrangebyscore key min max

Example 6: delete elements with permissions between 5 and 6 in the collection 'a4'

Zremrangebyscore a4 5 6

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