human
Complete the below
def get_ogr_db_string():

    ''''Construct the DB string that GDAL will use to inspect the database.
    GDAL will create its own connection to the database, so we re-use the
    connection settings from the Django test.'
    '''
 ... Write me a the Python program you requested?
assistant
#Here is the Python program you requested.
    db = connections.databases['default']
    drivers = {'django.contrib.gis.db.backends.postgis': ('PostgreSQL', "PG:dbname='%(db_name)s'", '    '), 'django.contrib.gis.db.backends.mysql': ('MySQL', 'MYSQL:"%(db_name)s"', ','), 'django.contrib.gis.db.backends.spatialite': ('SQLite', '%(db_name)s', '')}
    db_engine = db['ENGINE']
    if (db_engine not in drivers):
        return None
    (drv_name, db_str, param_sep) = drivers[db_engine]
    try:
        Driver(drv_name)
    except GDALException:
        return None
    if (db['NAME'] == ':memory:'):
        return None
    params = [(db_str % {'db_name': db['NAME']})]
    def add(key, template):
        value = db.get(key, None)
        if value:
            params.append((template % value))
    add('HOST', "host='%s'")
    add('PORT', "port='%s'")
    add('USER', "user='%s'")
    add('PASSWORD', "password='%s'")
    return param_sep.join(params)