wfLoadExtension('ExternalData');
$wgExternalDataSources['DataDemo'] = [
  'server' => 'localhost',
  'type' => 'mysql',
  'name' => 'demo',
  'user' => 'root',
  'password' => '***************',
  'prepared' => [
    'office' => [
      'query' => 'SELECT * FROM office',
      'types' => ''
    ],
    'employee' => [
      'query' => 'SELECT * FROM emp LEFT JOIN office ON office.office_id = emp.emp_office ORDER BY emp.emp_last, emp.emp_first',
      'types' => ''
    ],
    'oneOffice' => [
      'query' => "SELECT * FROM office WHERE office.office_city = ?",
      'types' => 's'
    ],
    'employeeCount' => [
      'query' => 'SELECT office.office_city, COUNT(emp.emp_id) AS employee_count FROM office LEFT JOIN emp ON office.office_id = emp.emp_office WHERE office.office_city = ? GROUP BY office.office_city',
      'types' => 's'
    ],
    'officeManager' => [
      'query' => 'SELECT emp.emp_first, emp.emp_last FROM emp LEFT JOIN office ON emp.emp_office = office.office_id WHERE office.office_city = ? AND emp.emp_role = 1',
      'types' => 's'
    ],
    'officeReceptionist' => [
      'query' => 'SELECT emp.emp_first, emp.emp_last FROM emp LEFT JOIN office ON emp.emp_office = office.office_id WHERE office.office_city = ? AND emp.emp_role = 2',
      'types' => 's'
    ]
  ]
];