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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def field_exists(app_name, model_name, field_name):
 """ Does the FK or M2M table exist in the database already? """

    model = apps.get_model(app_name, model_name)
    table_name = model._meta.db_table
    cursor = connection.cursor()
    field_info = connection.introspection.get_table_description(cursor, table_name)
    field_names = [f.name for f in field_info]
    return field_name in field_names