Thursday, August 24, 2023
Saturday, September 17, 2022
问题:SQL SERVER有数据备份功能但没有数据还原功能。...
Monday, September 12, 2022
问题:子查询的条件不依赖于父查询,这类查询称为嵌套子查询,否则称为()...
Saturday, September 17, 2022
Friday, September 16, 2022
Saturday, September 17, 2022
Friday, September 16, 2022
问题:关系数据库中的每个关系必须最低达到()范式,该范式中的每个属性都...
Monday, September 12, 2022
问题:实体完整性规则限制了()的取值。A、全码B、非主属性C、外码D、主属性...
Saturday, July 29, 2023
Friday, September 16, 2022
Saturday, September 17, 2022
Saturday, September 17, 2022
Saturday, September 17, 2022
问题:可以通过列号来读取记录集的内容,rs是一个Recordset对象...
Sunday, September 11, 2022
问题:外码的取值只能为NULL或对应主码的值,这是()...
Saturday, September 17, 2022
问题:SELECT语句中()子句用于选择满足给定条件的元组。...
Sunday, September 11, 2022
Monday, September 12, 2022
Sunday, September 11, 2022
问题:对上一级的一个记录不仅有若干个下一级记录相对应,而且对一个下一级记录也有若干个上一级记录相对应的数据是()。A、层次B、网状C、关系D、多对多...
Wednesday, January 3, 2024
问题:在SQL/CLI中,宿主程序与数据库交互过程中有哪几个重要记录?...
Monday, September 12, 2022