Trigger updating same table oracle
Concurrency control is nothing new, it is something that you need to deal with in a multi-user system regardless of the implementation technology being used.However, when you are using object technology and relational technology together you are in a situation where you are implementing structure in two places: In your object schema as classes that have interrelationships and in your data schema as tables with interrelationships.The important point is that business logic could be deployed to a wide number of platforms, to any of the boxes shown in Figure 1, as could entities. It is important to recognize that software development has become more complex over the years.For example, a new browser-based application could have Java Script embedded in the HTML code to perform simply data validation, the primary business objects could reside on the application servers, these objects in turn invoke several web services which wrap access to procedures deployed on the mainframe, and several stored procedures that encapsulate shared functions are implemented in the three relational databases accessed by the objects. One of the main reasons why the object-oriented paradigm was embraced so ardently by software developers is because it helped them to deal with this growing complexity.I read an existing order and its order items into memory on my computer. Shortly thereafter you read the exact same order and order items into memory on your computer.You decide to add a new order item, C, to the order and save it to the database.We now work with implementation languages such as C# and Java that implement entities called classes.
For example, if I claim to live in a house at 123 Main Street then that house must actually be there, otherwise we have an RI error.Relational database technology has also improved dramatically, supporting native programming languages to write stored procedures and triggers and even standard object programming languages such as Java.It is now viable to implement business logic in your database as well as in your application code.Figure 1 depicts a simplified deployment architecture diagram to provide an overview of the situation that developers face on a daily basis.Note that you may not have all of these platforms, or they might be connected in slightly different ways.