Error Handling Framework In Oracle
Contents |
shot at without result. —Winston Churchill Run-time errors arise from design faults, coding mistakes, hardware failures, and many other sources. Although you cannot anticipate all possible errors, you can plan to oracle error handling best practice handle certain kinds of errors meaningful to your PL/SQL program. With many programming
Oracle Error Handling In Stored Procedure
languages, unless you disable error checking, a run-time error such as stack overflow or division by zero stops normal processing
Error Handling Framework In Soa
and returns control to the operating system. With PL/SQL, a mechanism called exception handling lets you "bulletproof" your program so that it can continue operating in the presence of errors. This chapter contains
Error Handling Framework In Java
these topics: Overview of PL/SQL Runtime Error Handling Advantages of PL/SQL Exceptions Summary of 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 Errors Overview of PL/SQL Compile-Time Warnings Overview of PL/SQL Runtime Error Handling In PL/SQL, an error condition is called an exception. Exceptions can be error handling framework in informatica internally defined (by the runtime 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. After an exception handler runs, the current block stops executing and the enclosing block resumes with the next statement. If there is no enclosing block, control returns to the host environment. The following example calculates a price-to-earnings ratio for a company. If the company has zero earnings, the division operation raises the predef
services, and to generate error messages in response to business or runtime faults. This chapter also describes c# error handling framework how to use the fault management framework to catch faults and java error handling framework open source perform user-specified actions defined in a fault policy file. This chapter includes the following sections: Section 12.1, .net error handling framework "Introduction to a Fault Handler" Section 12.2, "Introduction to BPEL Standard Faults" Section 12.3, "Introduction to Categories of BPEL Faults" Section 12.4, "Using the Fault Management Framework" Section https://docs.oracle.com/cd/B13789_01/appdev.101/b10807/07_errs.htm 12.5, "Catching BPEL Runtime Faults" Section 12.6, "Getting Fault Details with the getFaultAsString XPath Extension Function" Section 12.7, "Throwing Internal Faults" Section 12.8, "Rethrowing Faults with the Rethrow Activity" Section 12.9, "Returning External Faults" Section 12.10, "Using a Scope Activity to Manage a Group of Activities" Section 12.11, "Re-executing Activities in a Scope Activity with the Replay https://docs.oracle.com/cd/E23943_01/dev.1111/e10224/bp_faults.htm Activity" Section 12.12, "Using Compensation After Undoing a Series of Operations" Section 12.13, "Stopping a Business Process Instance" Section 12.14, "Throwing Faults with Assertion Conditions" For additional information on creating fault handling in a SOA composite application, see the Fusion Order Demo application. 12.1 Introduction to a Fault Handler Fault handlers define how the BPEL process service component responds when web services return data other than what is normally expected (for example, returning an error message instead of a number). An example of a fault handler is where the web service normally returns a credit rating number, but instead returns a negative credit message. Figure 12-1 provides an example of how a fault handler sets a credit rating variable to -1000. Figure 12-1 Fault Handling Description of "Figure 12-1 Fault Handling" The code segment in Example 12-1 defines the fault handler for this operation in the BPEL file: Example 12-1 Fault Handler Definition you should consider them as your closest friends. They are the ones that honestly say what is wrong with your program. We cannot foresee all possible problematic events, and even the best programmers write http://allthingsoracle.com/error-handling/ bugs. Exceptions There are three kinds of exceptions Internally defined: A system error, defined by Oracle, that occurs. Predefined: The most common internally defined exceptions that are given predefined names. User defined: A logical error which you define and raise yourself System errors could occur from improper coding, like the “ORA-01001: Invalid cursor”, which you should try to fix as soon as possible in your code. And the “TOO_MANY_ROWS”-error might give you clues error handling about bad data quality. To resolve these bugs, it is important to know where, when and why it happened. But system errors could also occur from hardware failures, like the “ORA-12541: TNS: no listener”, when an ftp-server might be unreachable over the network. In that case, all you can do, and should do, is provide proper error handling and transaction management, and give as detailed information as possible about this situation to the error handling framework people that need to know. These system-errors always have an error number assigned, so you can easily identify the error. The 22 predefined exceptions also have a name assigned, which allows for easier, and more readable exception handling. For the other, non-predefined, system-errors, a name can be linked by using the pragma “EXCEPTION_INIT”. DECLARE network_error EXCEPTION; PRAGMA EXCEPTION_INIT(network_error, -12541); BEGIN ... EXCEPTION WHEN too_many_rows THEN ... WHEN network_error THEN ... END; User defined errors we will raise ourselves. They can be given a number and a name. To raise a user defined error with a chosen number and error message, we call the procedure “RAISE_APPLICATION_ERROR”. Oracle allows us the create error numbers in the range of -20000 to -20999. This allows us to create 1000 unique error codes for our logical errors throughout our application. Just like we did for system errors, we can name our user defined errors by using the pragma “EXCEPTION_INIT”. BEGIN RAISE_APPLICATION_ERROR(-20000,’Logical error occured’); END; If we do not care about the error code and error message, and we will foresee an exception block to directly handle the error, we could also raise errors by the keyword “RAISE”, followed by the exception name. If we do not handle the error, the error ORA-65000, “Unhandled user exception” is propagated. DECLARE logical_error EXCEPTION; BEGIN R