* @param dataType the data type of the column
* @return true if the column was successfully added or false otherwise
*/
protected final DBViewColumn addColumn(String columnName, DataType dataType)
{ // find column by name
DBViewColumn vc = new DBViewColumn(this, columnName, new DBValueExpr(db, null, dataType));
return (addColumn(vc) ? vc : null);
}