Memcached replace
Command
Memcached replace
Command is used to replace the existing key
(key) value
(data value)
If key
Does not exist, the replacement fails and you will get a response NOT_STORED
.
Syntax:
replace
The basic syntax format of the command is as follows:
replace key flags exptime bytes [noreply]
value
The parameters are described as follows:
key
Key valuekey-value
In the structurekey
Used to find cached valuesflags
Can include integer parameters for key-value pairs, which clients use to store additional information about key-value pairsexptime
Length of time to save key-value pairs in the cache (in seconds, 0 means forever)bytes
Number of bytes stored in the cachenoreply
(optional): this parameter tells the server that there is no need to return datavalue
The stored value (always in the second line) (which can be directly understood askey-value
In the structurevalue
)
Example
In the following example, we set:
Key → mykey
Flag → 0
Exptime → 900 (in seconds)
Bytes → 10 (bytes of data storage)
Value → data_value
In the following example, we use the key ‘mykey’’ and store the corresponding value data_value
. After execution, we replace the same key
The value of is’ some_other_value’
add mykey 0 900 10
data_value
STORED
get mykey
VALUE mykey 0 10
data_value
END
replace mykey 0 900 16
some_other_value
get mykey
VALUE mykey 0 16
some_other_value
END
Output
If the data is added successfully, the output:
STORED
Output information description:
STORED
Output after being saved successfullyNOT_STORED
Output after failed to perform replacement