ws-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Apache Wiki <wikidi...@apache.org>
Subject [Ws Wiki] Update of "Tuscany/TuscanyJava/DAS Java Overview/RDBDAS Java User Guide/Write Operation Ordering" by KevinWilliams
Date Mon, 02 Oct 2006 17:13:38 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Ws Wiki" for change notification.

The following page has been changed by KevinWilliams:
http://wiki.apache.org/ws/Tuscany/TuscanyJava/DAS_Java_Overview/RDBDAS_Java_User_Guide/Write_Operation_Ordering

------------------------------------------------------------------------------
  = Write Operation Ordering =
  
+ Relational databases often use [http://en.wikipedia.org/wiki/Referential_integrity Referential
Integrity (RI)] constraints to maintain database consistency. When RI is enabled, database
operations must be performed in a specific order that prevents invalid references. If this
order is not adhered to then the database will throw an exception rather than let the write
succeed.
  
- Relational databases often use [http://en.wikipedia.org/wiki/Referential_integrity Referential
Integrity (RI)] constraints to maintain database consistency. When using RI, database operations
must be performed in an order that prevents invalid references. The order in which deletes,
updates, and inserts are performed in an object model may not match the order required by
the database.
+ When an application makes modifications to a data graph and then asks the RDB DAS to "apply
changes", the DAS will create a "batch" of database writes that must be sorted and the executed
in the correct order to avoid RI Contraint exceptions.  A simple example will help here. 
Assume a database with two tables CUSTOMER and ORDER.  Also assume that the ORDER table has
a [http://en.wikipedia.org/wiki/Foreign_key foreign key] reference to
  

---------------------------------------------------------------------
To unsubscribe, e-mail: general-unsubscribe@ws.apache.org
For additional commands, e-mail: general-help@ws.apache.org


Mime
View raw message