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Memcached is an open source, high-performance, high-concurrency distributed memory cache system, written by the C language, a total of more than 2000 lines of code. From the software name, the first three characters "Mem" means memory, while the next five characters "cache" means caching, and the last character d, which means daemon, stands for server-side daemon mode service. Let's take a look at what the memcached database operation commands are!

Memcached usage

1. Connect to the memcache server: telnet 127.0.0.1 11211

The set command sets a value for a new or existing key

Set key flags exptime bytes [noreply]

Value

The add command is used to set the value to a new key. If the key already exists, it outputs NOT_STORED

Add key flags exptime bytes [noreply]

Value

The replace command replaces the value of an existing key. If the key does not exist, it outputs NOT_STORED

Replace key flags exptime bytes [noreply]

Value

The append command is used to add some data to an existing key. The data is stored after the existing data of the key

Append key flags exptime bytes [noreply]

Value

The prepend command is used to add some data to an existing key. The data will be stored in front of the existing data of the key

Prepend key key flags exptime bytes [noreply]

Value

The cas command is used to set the data if no one has updated it since the last time it was obtained. If the key is not in memcached, it returns NOT_FOUND

Cas key flags exptime bytes cas_key [noreply]

Value

The get command is used to get the value stored in the key. If the key does not exist in memcached, it does not return a value

Get key

The gets command is used to get the cas token value. If the key does not exist in memcached, it does not return a value

Gets key

The delete command is used to delete existing keys from the memcached server

Delete key

The incr command is used to increase the value of an existing key. If the key is not found or if the key is not a number, return NOT_FOUND

Incr key value

The decr command is used to reduce the number of existing keys. If the key is not found or if the key is not a number, return NOT_FOUND

Decr key value

The flush_all command deletes all data (key-value pairs) from the memcached server. It accepts an optional parameter called time, which means that all memcached data after this time will be cleared.

The stats command is used to return server statistics such as pid, version, connection, etc.

Key is the name of the key (key) from the data stored in Memcached and obtained from memcached.

Flags is a 32-bit unsigned integer, the data used when the item is retrieved (provided by the user), and returned to the server for storage along the data.

Exptime expires in seconds, 0 means there is no delay, and if exptime is greater than 30 days, Memcached will use it as the UNIX timestamp to expire.

Bytes is the number of bytes that need to be stored in the data block. Basically, this is the length of the data that needs to be stored in memcached.

Cas_key gets a unique key from the gets command.

The noreply (optional) parameter tells the server not to send a reply

Value is a data that needs to be stored. After the data needs to execute the command with the above options, it will pass through a new line.

After reading the above, do you know anything about memcached database operation commands? If you want to know more, you are welcome to follow the industry information.

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