title: how to fetch data from two collection in arangodb
body: <p>my project backend is arangodb. I have two collections named "test" and "demo". i need to fetch data from both these tables. my data is like this:</p>
  
  <p>test</p>
  
  <pre><code>[
    {
      "firstName": "abc",
      "lastName": "pqr",
      "company": "abc Industries",
      "id": "1234"
    },
    {
      "firstName": "xyz",
      "lastName": "qwe",
      "company": "xyz Industries",
      "id": "5678"
    }
  ] 
  </code></pre>
  
  <p>demo</p>
  
  <pre><code>[
    {
      "clientId": "1234",
      "subject": "test",
      "message": "testing",
      "priority": "High",
      "status": "closed",
      "id": "111111"
    },
    {
      "clientId": "1234", 
      "subject": "hiii",
      "message": "demo",
      "priority": "High",
      "status": "closed",
      "id": "222222"
    },
  ]
  </code></pre>
  
  <p>in this id of the test is same as clientid of the demo. i need to select data from the table that is data of the client "1234". how can i implement this using AQL(arango query language). i am new to arango. any suggestion will highly appreciable.</p>