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 . 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. 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. 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