Review: Database Access

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Review Database Access

• Shoujing Liu
• Wangzhong Lu
• Wei Qu

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Client/Server Architecture1
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Benefits

• No data processing for client side
• Independent on the physical location of data
• Client side optimized for data presentation
• Server side optimized for data processing and
  storage
• Minimize network traffic

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Visual Basic

• VB
• Form
• DAO ,ADO,RDO
• Data-aware Object
• ODBC

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Oracle Developer2000

• Form Builder
• Form, Menu, PL/SQL Object
• Data Block
• Compile and Run the Form
• Report Builder

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Trigger

• What is Database Trigger?
• A stored procedure fired on table modification
• Trigger vs. Procedure
• Declarative Integrity Constraints vs. Trigger
• Creating, Dropping

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Transaction Management

• Transaction
• Logic unit of work that comprises one or more
  SQL statements by single user
• Begin with users first executable SQL statement
• End when it is explicitly committed or rolled
  back

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Transaction Example 3
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Commit/Rollback

• Commit
• Rollback
• Guarantee consistent changes to data

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Reference

• 1 Client/Server Architecture, Oracle 7 Server
  Concepts Manual,Online http//technet.oracle.com
  /doc/server73x/SCN73/ch20.htmindex2215 June 6,
  2000
• 2 Overview of Transaction, Oracle 7 Server
  Concepts Manual,Online http//technet.oracle.com
  /doc/server73x/SCN73/ch1.htmindex0197 June 6,
  2000
• 3 Using Database trigger, Oracle 7 Server
  Application Developers Guide, Online
  http//technet.oracle.com/doc/server71x/SVAPG/ch8.
  htm June 6, 2000