Enable DB Query in HUE web UI

put configuration in HUE as below:

[librdbms]
  # The RDBMS app can have any number of databases configured in the databases
  # section. A database is known by its section name
  # (IE sqlite, mysql, psql, and oracle in the list below).

  `databases`
    # sqlite configuration.
    ## [`sqlite`]
      # Name to show in the UI.
     ## nice_name=SQLite

      # For SQLite, name defines the path to the database.
      #name=/tmp/sqlite.db
     
      # Database backend to use.
      #engine=sqlite

      # Database options to send to the server when connecting.
      # https://docs.djangoproject.com/en/1.4/ref/databases/
      ## options={}

    
    # mysql, oracle, or postgresql configuration.
    [`mysql`]
      # Name to show in the UI.
      nice_name="My SQL DB"

      # For MySQL and PostgreSQL, name is the name of the database.
      # For Oracle, Name is instance of the Oracle server. For express edition
      # this is 'xe' by default.
      name=dbname

      # Database backend to use. This can be:
      # 1. mysql
      # 2. postgresql
      # 3. oracle
      engine=mysql

      # IP or hostname of the database to connect to.
      host=mysql-server-ip

      # Port the database server is listening to. Defaults are:
      # 1. MySQL: 3306
      # 2. PostgreSQL: 5432
      # 3. Oracle Express Edition: 1521
      ## port=3306

      # Username to authenticate with when connecting to the database.
      user=username

      # Password matching the username to authenticate with when
      # connecting to the database.
      password=password

      # Database options to send to the server when connecting.
      # https://docs.djangoproject.com/en/1.4/ref/databases/
      ## options={}

restart HUE service

ok