《数据库管理系统》教案第四章.ppt

➢ How to add fields to a query, change the sort order
of a query, and modify a query's criteria
➢ How to save a query
➢ How to print query results
➢ How to close a query
Select： 选择查询
Total： 汇总查询
Action： 动作查询
Crosstab： 交叉表查询
SQL： SQL查询
Top(n)： 前 n 项查询
Select These are the most common. As its name
implies, the select query selects information from one or more tables (based on specific criteria), and displays the information in a
You use a simple Select query to define the tables and fields whose data you want to view
and also to specify the criteria that limits the
data the query's output displays. A Select query is a query of a table or tables that just displays data; the query doesn't modify data in any way.
➢ What is a query ? 什么是查询
A Select query is a stored question about the
data stored in a database's tables.
一个选择查询 是对存储在表（Tables）中数据
的一种提问。
Select queries are the foundation of much of
4.3 Creating Queries
创建查询
4.1 Understanding and Using Simple Queries
Hour 3. Queries Introduced
Queries are stored questions about data. They are an extremely powerful aspect of Microsoft Access. By using queries, you can retrieve just the data you want, how you want it, whenever you want it. In this hour you'll learn the following:
For example：The datasheet view of the “ Current Product List ” query is shown in Figure 4-1.
Figure 4-1
➢ Types of queries
查询的类型
Access supports many different types of queries. They can be grouped into six basic categories:
dynaset that you can use to view and
analyze specific data; you can make changes to your data in the underlying tables. (see Figure 4-1.)
Figure 4-1 The “Current Product List”query in datasheet view
A Microsoft Access query is a question that you ask about the information stored in your Access tables. The way you ask questions about this information is by using the query tools. Your query can be a simple question about information stored in a single table, or it can be a complex question about information stored in several tables. After you ask the question, Microsoft Access returns only the information you requested.
➢ What is a query?
什么是查询
➢ Types of queries
查询的类型
ห้องสมุดไป่ตู้
➢ Query capabilities 查询的功能
➢ How to open a query in Datasheet view
➢ How to open a query in Design view
➢ How to run a query
第四章 创建查询 Creating Queries
4.1 Understanding and Using Simple Queries
了解和使用简单查询
Hour 3. Queries Introduced 4.2 Using Operators, Functions and Expressions
使用运算符、函数和表达式
what you do in Access. They underlie most forms and reports, and they allow you to view the data you want, when you want. 选择查询是许多工作的基础。
In another words: