1.9. Memcached prepend command

1.9.1. Syntax: ¶

The prepend basic syntax format of the command is as follows:

prepend key flags exptime bytes [noreply] value 

The parameters are described as follows:

• key :Key value key-value in the structure key used to find cached values

• flags :Can include integer parameters for key-value pairs, which clients use to store additional information about key-value pairs

• exptime :Length of time to save key-value pairs in the cache (in seconds,0 means forever)

• bytes :Number of bytes stored in the cache

• noreply (optional): this parameter tells the server that there is no need to return data

• value :The stored value (always in the second line) (which can be directly understood as key-value in the structure value )

1.9.2. Example ¶

Examples are as follows:

• First we store a key in Memcached runoob whose value is memcached .

• Then, we use the get command to retrieve the value.

• Then, we use the prepend command before the key is runoob append “redis” to the value.

• Finally, we will use the get command to retrieve the value.

set runoob 0 900 9 memcached STORED get runoob VALUE runoob 0 9 memcached END prepend runoob 0 900 5 redis STORED get runoob VALUE runoob 0 14 redismemcached END 

1.9.3. Output ¶

If the data is added successfully, the output:

STORED 

Output information description:

• STORED :Output after being saved successfully

• NOT_STORED :The key does not exist on Memcached

• CLIENT_ERROR :Execution error.