Operations for Redis String types

Set key value [ex seconds]/[px milliseconds]  [NX]/[xx]

such as: Set a 1 ex 10, 10 seconds valid

Set a 1 PX 9000, 9 sec active

Note: If EX,PX is written at the same time, the following validity period shall prevail

If set a 1 ex 9000 px, the actual validity is 9000 milliseconds

NX: Indicates that the key does not exist when the operation is performed

XX: Indicates that the key exists, the operation is performed

Mset  Multi Set, setting multiple key values at once

Example: Mset key1 v1 key2 v2 ....

Get key

Function: Gets the value of key

Mget Key1 Key2. Keyn

Function: Gets the value of multiple keys

SetRange Key Offset value

Function: Change the offset byte of the string to value

Redis 127.0.0.1:6379> Set Greet Hello

Ok

Redis 127.0.0.1:6379> SetRange greet 2 x

(integer) 5

Redis 127.0.0.1:6379> Get Greet

"Hexlo"

Note: If offset > character length, the character automatically complements 0x00

Redis 127.0.0.1:6379> SetRange greet 6!

(integer) 7

Redis 127.0.0.1:6379> Get Greet

"Heyyo\x00!"

Append key value

Function: Append value to the original value of key

GetRange Key Start stop

Function: Gets the value of the [Start, stop] range in the string

Note: For the subscript of a string, the left number starts at 0 and the right number starts at-1

Redis 127.0.0.1:6379> set title ' Chinese '

Ok

Redis 127.0.0.1:6379> GetRange Title 0 3

"Chin"

Redis 127.0.0.1:6379> getrange Title 1-2

"Hines"

Attention:

1:start>=length, the empty string is returned

2:stop>=length, it is truncated to the end of the character

3: Returns an empty string if start is located on the right side of stop

Getset Key NewValue

Function: Gets and returns the old value, sets the new value

Redis 127.0.0.1:6379> Set CNT 0

Ok

Redis 127.0.0.1:6379> Getset CNT 1

"0"

Redis 127.0.0.1:6379> Getset CNT 2

"1"

INCR key

Function: The value of the specified key is added 1, and the value after the plus 1 is returned

Attention:

1: Non-existent key as 0, then incr operation

2: The range is 64 signed

Incrby Key number

Redis 127.0.0.1:6379> Incrby Age 90

(integer) 92

Incrbyfloat Key Floatnumber

Redis 127.0.0.1:6379> Incrbyfloat Age 3.5

"95.5"

DECR key

Redis 127.0.0.1:6379> Set age 20

Ok

Redis 127.0.0.1:6379> DECR Age

(integer) 19

Decrby Key number

Redis 127.0.0.1:6379> Decrby Age 3

(integer) 16

Getbit Key Offset

Function: Gets the binary representation of the value, the value on the corresponding bit (from left, numbering from 0)

Redis 127.0.0.1:6379> Set Char A

Ok

Redis 127.0.0.1:6379> getbit Char 1

(integer) 1

Redis 127.0.0.1:6379> Getbit Char 2

(integer) 0

Redis 127.0.0.1:6379> Getbit Char 7

(integer) 1

Setbit  Key Offset value

Set the value on offset corresponding to bits

Return: The old value on this bit

Attention:

1: If offset is too large, 0 is filled in the middle,

2:offset Maximum to what size

3:offset maximum 2^32-1, can be launched the largest string of 512M

Bitop Operation Destkey Key1 [Key2 ...]

To Key1,key2. Keyn as operation, and save the results to Destkey.

Operation can be and, or, not, XOR

Redis 127.0.0.1:6379> setbit Lower 7 0

(integer) 0

Redis 127.0.0.1:6379> setbit Lower 2 1

(integer) 0

Redis 127.0.0.1:6379> Get Lower

" "

Redis 127.0.0.1:6379> Set Char Q

Ok

Redis 127.0.0.1:6379> Get Char

"Q" L

Redis 127.0.0.1:6379> bitop or char char lower

(integer) 1

Redis 127.0.0.1:6379> Get Char

"Q"

Note: For not operations, key cannot be multiple

Operations for Redis String types