具备多表组合查询组件功能。通过将表字段与表间关系映射到对象关系及属性，可以依据查询条件，由程序自动拼成查询语句，从而进行灵活的多表组合查询。-Combination with multi-table query components function. Table by the relationship between field and table is mapped to the object relations and attributes, can be based on query