java left logo
java middle logo
java right logo
 

Home arrow Java EE Tips arrow JavaServer Pages arrow Executing database transactions
 
 
Main Menu
Home
Java Tutorials
Book Reviews
Java SE Tips
Java ME Tips
Java EE Tips
Other API Tips
Java Applications
Java Libraries
Java Games
Java Network
Java Forums
Java Blog




Most Visited Tips
Java SE Tips
Java ME Tips
Java EE Tips
Other API Tips
Java Applications
Java Libraries
Java Games
Book Reviews
Top Rated Tips
Java SE Tips
Java ME Tips
Java EE Tips
Other API Tips
Java Applications
Java Libraries
Java Games
Book Reviews


Statistics
Registered Users: 3894
Java SE Tips: 614
Java ME Tips: 202
Java EE Tips: 183
Other API Tips: 779
Java Applications: 298
Java Libraries: 209
Java Games: 16
Book Reviews:
 
 
 
Executing database transactions E-mail
User Rating: / 10
PoorBest 

It's often desirable to execute a group of SQL updates or queries atomically; for example, if you transfer funds from bank account A to bank account B, you don't want to deposit the money in account B if the withdrawal from account A failed. Database transactions let you treat any number of SQL updates atomically-if one of the updates fails, the entire transaction is rolled back. The transaction is committed only if all of the updates are successful. JSTL supports database transactions with the action. This sample shows how this action can be used for safe access to a database:

<%@ taglib uri='http://java.sun.com/jstl/core' prefix='c'%>
<%@ taglib uri='http://java.sun.com/jstl/sql' prefix='sql'%>
<%@ taglib uri='http://java.sun.com/jstl/fmt' prefix='fmt'%>

<html>
	...

	<body>

/// the transaction is enclosed in a <c:catch> action. if the 
/// transaction fails, the <sql:transaction> action will throw 
/// an exception, which <c:catch> stores in a scoped variable 
/// named transactionException:

	<c:catch var='transactionException'>
		
		<%-- The transaction... --%>
		<sql:transaction>
		
			<%-- Withdraw money from the "from" 
			     customer's account --%>
			     
			<sql:update>
				...
			</sql:update>
	
			...
		</sql:transaction>
	</c:catch>

/// if the transactionException scoped variable is not empty, 
/// the transaction failed:
	<c:if test='${not empty transactionException}'>
		<%-- Display the error message --%>
		<font size='4' color='red'>
			Transaction Failed!
		</font>
	</c:if>
	...

	</body>
	
</html>


 Related Tips

 
< Prev   Next >

Page 1 of 0 ( 0 comments )

You can share your information about this topic using the form below!

Please do not post your questions with this form! Thanks.


Name (required)


E-Mail (required)

Your email will not be displayed on the site - only to our administrator
Homepage(optional)



Comment Enable HTML code : Yes No



 
       
         
     
 
 
 
   
 
 
java bottom left
java bottom middle
java bottom right
RSS 0.91 FeedRSS 1.0 FeedRSS 2.0 FeedATOM FeedOPML Feed

Home - About Us - Privacy Policy
Copyright 2005 - 2008 www.java-tips.org
Java is a trademark of Sun Microsystems, Inc.