Oracle Pl Sql Error Handling Package
Contents |
Churchill Run-time errors arise from design faults, coding mistakes, hardware failures, and many other sources. Although you cannot anticipate
Pl Sql Exception Handling Examples
all possible errors, you can plan to handle certain kinds of pl sql exception handling best practices errors meaningful to your PL/SQL program. With many programming languages, unless you disable error checking, a run-time
Pl/sql Exception When Others
error such as stack overflow or division by zero stops normal processing and returns control to the operating system. With PL/SQL, a mechanism called exception handling lets you exception handling in oracle interview questions "bulletproof" your program so that it can continue operating in the presence of errors. This chapter discusses the following topics: Overview of PL/SQL Error Handling Advantages of PL/SQL Exceptions Predefined PL/SQL Exceptions Defining Your Own PL/SQL Exceptions How PL/SQL Exceptions Are Raised How PL/SQL Exceptions Propagate Reraising a PL/SQL Exception Handling Raised PL/SQL Exceptions Tips for Handling pl/sql logging best practices PL/SQL Errors Overview of PL/SQL Error Handling In PL/SQL, a warning or error condition is called an exception. Exceptions can be internally defined (by the run-time system) or user defined. Examples of internally defined exceptions include division by zero and out of memory. Some common internal exceptions have predefined names, such as ZERO_DIVIDE and STORAGE_ERROR. The other internal exceptions can be given names. You can define exceptions of your own in the declarative part of any PL/SQL block, subprogram, or package. For example, you might define an exception named insufficient_funds to flag overdrawn bank accounts. Unlike internal exceptions, user-defined exceptions must be given names. When an error occurs, an exception is raised. That is, normal execution stops and control transfers to the exception-handling part of your PL/SQL block or subprogram. Internal exceptions are raised implicitly (automatically) by the run-time system. User-defined exceptions must be raised explicitly by RAISE statements, which can also raise predefined exceptions. To handle raised exceptions, you write separate routines called exception handlers. Afte
Magazine Online 2016 2015 2014 2013 2012 2011 2010 As Published In May/June 2003 TECHNOLOGY: PL/SQL Managing Exceptional Behavior, Part 1 By Steven Feuerstein Handle PL/SQL exceptions with best practices. Many programmers don't take the time to properly bulletproof their programs. Most of us find it
Raise_application_error
hard enough—and more than enough work—to simply write the code that implements the positive aspects of pragma exception_init an application: maintaining customers, generating invoices, and so on. You write applications that often assume the best of all possible worlds, hoping that your
Oracle Function Exception Return
programs are bug-free, that users will enter only the correct data in only the correct fashion, and that all systems (hardware and software) will always be a "go." No matter how hard you try, there will always be one more https://docs.oracle.com/cd/A97630_01/appdev.920/a96624/07_errs.htm bug in your application. And your users will always find just the right sequence of keystrokes it takes to make a screen implode. The reality is clear: Either you spend the time up front to properly debug and bulletproof your programs, or you will fight an unending series of rear-guard battles, taking frantic calls from your users and putting out the fires. Fortunately, PL/SQL offers a powerful and flexible way to trap and handle errors in your programs. It http://www.oracle.com/technetwork/issue-archive/o33plsql-083386.html is entirely feasible within the PL/SQL language to build an application that fully protects the user and the database from errors. And if you go about it correctly, you minimize the amount of code you need to write to get the job done. This article, the first of two parts, will explore a set of best practices you should follow to incorporate high-quality, comprehensive error handling in your PL/SQL-based applications. This article will start by considering some overall best practices for error handling and then focus on best practices relating to raising exceptions. The next article will move on to how best to handle exceptions. Set Guidelines before You Start Before you start writing any application code, you first need to decide on your overall strategy for error handling, as well as specific coding guidelines. There is no single strategy that works for all applications; you have to decide what makes the most sense for your particular system. You may determine, for example, that all stored procedures should have an exception section so that errors are trapped and handled as close as possible to the block in which they were raised. You might, on the other hand, decide that you want an exception section only at the outer-most block. Once you have set the overall approach, you need to face up to the challenge of getting all developers on the team to write their error handling i
March 2012 Oracle Magazine Online 2016 2015 2014 2013 2012 2011 2010 January 2012 March 2012 May 2012 July 2012 September 2012 November 2012 As Published In March/April http://www.oracle.com/technetwork/issue-archive/2012/12-mar/o22plsql-1518275.html 2012 TECHNOLOGY: PL/SQL Error Management By Steven Feuerstein Part 6 in a series of articles on understanding and using PL/SQL Even if you write absolutely perfect PL/SQL programs, it is possible and even likely that something will go wrong and an error will occur when those programs are run. How your code responds to and deals with that error pl sql often spells the difference between a successful application and one that creates all sorts of problems for users as well as developers. This article explores the world of error management in PL/SQL: the different types of exceptions you may encounter; when, why, and how exceptions are raised; how to define your own exceptions; how you can handle exceptions when they occur; pl sql exception and how you can report information about problems back to your users. Exception Overview There are three categories of exceptions in the world of PL/SQL: internally defined, predefined, and user-defined. An internally defined exception is one that is raised internally by an Oracle Database process; this kind of exception always has an error code but does not have a name unless it is assigned one by PL/SQL or your own code. An example of an internally defined exception is ORA-00060 (deadlock detected while waiting for resource). A predefined exception is an internally defined exception that is assigned a name by PL/SQL. Most predefined exceptions are defined in the STANDARD package (a package provided by Oracle Database that defines many common programming elements of the PL/SQL language) and are among the most commonly encountered exceptions. One example is ORA-00001, which is assigned the name DUP_VAL_ON_INDEX in PL/SQL and is raised when a unique index constraint is violated. A user-defined exception is one you have declared in the declaration section of a program unit. User-defined exceptions can be associated with an internally
be down. Please try the request again. Your cache administrator is webmaster. Generated Sun, 23 Oct 2016 17:23:19 GMT by s_wx1085 (squid/3.5.20)