private Collection<Var> migrateColumns(SQLTable currentTable){
  List<Var> vars=new ArrayList<>();
  String tableType=currentTable.getEntityType();
  Map<String,ResourceType.DataType> columns=currentTable.getColumns();
  Map<String,String> foreignColumns=currentTable.getForeignKeyColumns();
  for (  String column : columns.keySet()) {
    ResourceType.DataType columnType=columns.get(column);
    if (foreignColumns.containsKey(column)) {
      vars.addAll(migrateAsRelation(tableType,column,foreignColumns.get(column)));
    }
 else {
      vars.addAll(migrateAsResource(tableType,columnType,column));
    }
  }
  return vars;
}

private Collection < Var > migrateColumns ( SQLTable currentTable ) { List < Var > vars = new ArrayList < > ( ) ; String tableType = currentTable . getEntityType ( ) ; Map < String , ResourceType . DataType > columns = currentTable . getColumns ( ) ; Map < String , String > foreignColumns = currentTable . getForeignKeyColumns ( ) ; for ( String column : columns . keySet ( ) ) { ResourceType . DataType columnType = columns . get ( column ) ; if ( foreignColumns . containsKey ( column ) ) { vars . addAll ( migrateAsRelation ( tableType , column , foreignColumns . get ( column ) ) ) ; } else { vars . addAll ( migrateAsResource ( tableType , columnType , column ) ) ; } } return vars ; }
loop through each of the columns in the given table , migrating each as a resource or relation .
