《ACCESS实例教程第3章.ppt

ACCESS实例教程 ——查询的操作（第3章） 3.6 建立操作查询 操作查询包括：生成表查询、更新查询、追加查询、删除查询。 3.6.1 生成表查询 生成表查询能将查询结果保存成数据表，使查询结果由动态数据集合转化为静态的数据表。新表不继承数据源表的关键字属性。 生成表查询通常用几个表中的数据组合起来生成新表，如果仅用一个表的数据生成新表，可以在数据库窗口用复制、粘贴的方法实现。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 例： 将男学生成绩查询转换成数据表 （1）先建查询 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. （2）将查询转换为生成表查询 （3）为新表起名 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. （4）单击“运行”按钮 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3.6.2 更新查询 更新查询能成批修改记录。用更新查询更改记录的数据项以后，无法用“撤消”命令取消操作。更新查询可以同时更新多个数据源和多个字段的值。在设计网格中，只将要更新的字段和做条件的字段放入即可。 例：将职称为讲师的“教师编号”字段前加“讲师”字符串，并将讲师的奖金增加50%。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 3.6.3 追加查询 追加查询能将数据源中符合条件的记录追加到另一个表尾部。数据源可以是表或查询，追加的去向是一个表。字段列表区只放提供字段的表或查询，被追加的表不能放入查询的字段列表区。数据源与被追加表对应的字段之间要类型匹配。 Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd. 例：将籍贯为河北的记录追加到空表stud中，追加的字段 为：