Memcached - Delete Key

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Memcached delete command is used to delete an existing key from the Memcached server.

Syntax

The basic syntax of Memcached delete command is as shown below −

delete key [noreply]

Output

CAS command may produce one of the following result −

  • DELETED indicates successful deletion.

  • ERROR indicates error while deleting data or wrong syntax.

  • NOT_FOUND indicates that the key does not exist in the Memcached server.

Example

In this example, we use howcodex as a key and store memcached in it with an expiration time of 900 seconds. After this, it deletes the stored key.

set howcodex 0 900 9
memcached
STORED
get howcodex
VALUE howcodex 0 9
memcached
END
delete howcodex
DELETED
get howcodex
END
delete howcodex
NOT_FOUND

Delete Data Using Java Application

To delete data from a Memcached server, you need to use the Memcached delete method.

Example

import java.net.InetSocketAddress;
import java.util.concurrent.Future;

import net.spy.memcached.MemcachedClient;

public class MemcachedJava {
   public static void main(String[] args) {
   
      try{
   
         // Connecting to Memcached server on localhost
         MemcachedClient mcc = new MemcachedClient(new InetSocketAddress("127.0.0.1", 11211));
         System.out.println("Connection to server sucessful.");

         // add data to memcached server
         Future fo = mcc.set("howcodex", 900, "World's largest online tutorials library");

         // print status of set method
         System.out.println("set status:" + fo.get());

         // retrieve and check the value from cache
         System.out.println("howcodex value in cache - " + mcc.get("howcodex"));

         // try to add data with existing key
         Future fo = mcc.delete("howcodex");

         // print status of delete method
         System.out.println("delete status:" + fo.get());

         // retrieve and check the value from cache
         System.out.println("howcodex value in cache - " + mcc.get("codingground"));

         // Shutdowns the memcached client
         mcc.shutdown();
         
      }catch(Exception ex)
         System.out.println(ex.getMessage());
   }
}

Output

On compiling and executing the program, you get to see the following output −

Connection to server successful
set status:true
howcodex value in cache - World's largest online tutorials library
delete status:true
howcodex value in cache - null
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