slide cơ sở dữ liệu tiếng anh chương (7) query-by-example transparencies

Chapter 7
Query-by-Example
Transparencies
© Pearson Education Limited 1995, 2005
2
Chapter 7 - Objectives

The main features of Query-By-Example (QBE).

The types of queries provided by the Microsoft
Access DBMS QBE facility.

How to use QBE to build queries to select fields
and records.

How to use QBE to target single or multiple tables.
© Pearson Education Limited 1995, 2005
3
Chapter 7 - Objectives

How to perform calculations using QBE.

How to use advanced QBE facilities including
parameter, find matched, find unmatched,
crosstab, and autolookup queries.

How to use QBE action queries to change
content of tables.
© Pearson Education Limited 1995, 2005
4
Query-by-Example (QBE)


Visual approach for accessing information in a
database through use of query templates.

Example values are entered into template to
represent what access to database is to achieve,
such as the answer to a query.

Originally developed by IBM in 1970s and has
proved so popular that QBE (or similar) is now
provided by most DBMSs.

When user constructs a QBE - in background,
DBMS creates an equivalent SQL statement.
© Pearson Education Limited 1995, 2005
5
Query-by-Example (QBE)

Allows user to:
- Ask questions about data in one or more tables.
- Specify the fields we want in the answer.
- Select records according to some criteria.
- Perform calculations on the data in tables.
- Insert and delete records.
- Modify values of fields.
- Create new fields and tables.
© Pearson Education Limited 1995, 2005
6
Introduction to Microsoft Access
© Pearson Education Limited 1995, 2005

7
Summary of Microsoft Access Query Types
© Pearson Education Limited 1995, 2005
8
Introduction to Microsoft Access Queries
© Pearson Education Limited 1995, 2005
9
Building Select Queries using QBE -
Specifying Criteria
© Pearson Education Limited 1995, 2005
10
Building Select Queries using QBE -
Specifying Criteria
© Pearson Education Limited 1995, 2005
11
Building Select Queries using QBE -
Specifying Criteria
© Pearson Education Limited 1995, 2005
12
Creating Multi-table Queries
© Pearson Education Limited 1995, 2005
13
Calculating Totals
© Pearson Education Limited 1995, 2005
14
Calculating Totals
© Pearson Education Limited 1995, 2005
15
Using Advanced Queries - Parameter Query
© Pearson Education Limited 1995, 2005

16
Using Advanced Queries - Crosstab Query
© Pearson Education Limited 1995, 2005
17
Using Advanced Queries - Crosstab Query
© Pearson Education Limited 1995, 2005
18
Using Advanced Queries - Find Matched Query
© Pearson Education Limited 1995, 2005
19
Using Advanced Queries - Find Unmatched Query
© Pearson Education Limited 1995, 2005
20
Using Advanced Queries - Autolookup Query
© Pearson Education Limited 1995, 2005
21
Changing Content of Tables - Make-Table
Action Query
© Pearson Education Limited 1995, 2005
22
Changing Content of Tables - Delete
Action Query
© Pearson Education Limited 1995, 2005
23
Changing Content of Tables - Update
Action Query
© Pearson Education Limited 1995, 2005
24
Changing Content of Tables - Append
Action Query

© Pearson Education Limited 1995, 2005
25
Changing Content of Tables - Append
Action Query
© Pearson Education Limited 1995, 2005