Chapter 9

Query-by-Example

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Chapter 9 - 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.

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Chapter 9 - 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.

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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.

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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.

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Introduction to Microsoft Access

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Summary of Microsoft Access Query Types

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Introduction to Microsoft Access Queries

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Building Select Queries using QBE - Specifying Criteria

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Building Select Queries using QBE - Specifying Criteria

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Building Select Queries using QBE - Specifying Criteria

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Creating Multi-table Queries

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Calculating Totals

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Calculating Totals

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Using Advanced Queries - Parameter Query

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Using Advanced Queries - Crosstab Query

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Using Advanced Queries - Crosstab Query

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Using Advanced Queries - Find Matched Query

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Using Advanced Queries - Find Unmatched Query

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Using Advanced Queries - Autolookup Query

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Changing Content of Tables - Make-Table Action Query

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Changing Content of Tables - Delete Action Query

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Changing Content of Tables - Update Action Query

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Changing Content of Tables - Append Action Query

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Changing Content of Tables - Append Action Query

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