如果只能检索包含出生日期元素的交易，必须在where语句中使用exists函数，如清单10所示。
If it is necessary to retrieve only those transactions that specify elements for birth date, then the exists function is added to the where statement, as in Listing 10.
本文系统阐述了生产函数的经济意义、数学定义，并且给出生产函数一个严格的数学建模。
The paper systematically presents the economic significance of production function, maths definition and give a strict maths model.
应用推荐