# Connection

  connection to a RDBMS.

## class methods:

  `connect(url, prop={})`

    same as DriverManager.getConnection(url, prop). returns a new Connection object if connect OK.

## methods:

  `createStatement(sql=nil)`

    If OK, returns a Statement object.
    specify `sql` string to make the Statement object PREPARED.

  `close`

    closes self and children.

  `commit`

    commit.

  `rollback`

    rollback.

  `autocommit`

    returns if self is "auto commit".

  `autocommit=`

    sets "auto commit".