Raise Error In Oracle
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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 handle certain kinds
Oracle Raise_application_error
of errors meaningful to your PL/SQL program. With many programming languages, unless you difference between raise and raise_application_error in oracle disable error checking, a run-time error such as stack overflow or division by zero stops normal processing and returns control
Oracle Raise No_data_found
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 discusses the following topics: raise without exception name oracle 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 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 raise user defined exception in oracle stored procedure 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. In the example below, you calculate and store a price-to-earnings ratio for a company with ticker symbol XYZ. If the company has zero earnings, the predefined exception ZERO_DIVIDE
user-defined exceptions whose names you decide. For more information, see "Defining Your Own PL/SQL
Oracle User Defined Exception Code Range
Exceptions". Syntax raise statement ::= Description of the illustration raise_statement.gif oracle raise exception in trigger Keyword and Parameter Description exception_name A predefined or user-defined exception. For a list of
Oracle Function Exception Example
the predefined exceptions, see "Summary of Predefined PL/SQL Exceptions". Usage Notes PL/SQL blocks and subprograms should RAISE an exception only when an error https://docs.oracle.com/cd/A97630_01/appdev.920/a96624/07_errs.htm makes it impractical to continue processing. You can code a RAISE statement for a given exception anywhere within the scope of that exception. When an exception is raised, if PL/SQL cannot find a handler for it in the current block, the exception propagates to successive enclosing blocks, until http://docs.oracle.com/cd/B19306_01/appdev.102/b14261/raise_statement.htm a handler is found or there are no more blocks to search. If no handler is found, PL/SQL returns an unhandled exception error to the host environment. In an exception handler, you can omit the exception name in a RAISE statement, which raises the current exception again. This technique allows you to take some initial corrective action (perhaps just logging the problem), then pass control to another handler that does more extensive correction. When an exception is reraised, the first block searched is the enclosing block, not the current block. Examples For examples, see the following: Example 1-12, "Creating a Stored Subprogram" Example 9-3, "Creating the emp_admin Package" Example 10-3, "Scope of PL/SQL Exceptions" Example 10-9, "Reraising a PL/SQL Exception" Related Topics "Exception Definition" Scripting on this page enhances content navigation, but does not change the content in any way.
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RAISE_APPLICATION_ERROR tips Oracle Database Tips by Burleson Consulting http://docstore.mik.ua/orelly/oracle/prog2/ch08_05.htm March 3, 2015 Question: What does the PL/SQL raise_application_error code do? Answer: The raise_application_error is actually a procedure defined by Oracle that allows the developer to raise in oracle an exception and associate an error number and message with the procedure. This allows the application to raise application errors rather than just Oracle errors. Error numbers are defined between -20,000 and -20,999. Oracle provides the raise_application_error procedure to allow you to raise custom error numbers within your applications. You can generate errors and their associated error in oracle text starting with -20000 and proceeding through -20999 (a grand total of 1,000 error numbers that you can use). Below we illustrate the use of the raise_application_error procedure. Using the raise_application_error procedure: DECLARE Balance integer := 24; BEGIN IF (nBalance <= 100) THEN Raise_Application_Error (-20343, 'The balance is too low.');END IF;END; In this example, error number -20343 is raised if the value of nBalance isn't greater than 100, yielding a message that looks like this: ORA-20343: The balance is too low. All other numbers belong to Oracle for its own errors. The message can be anything that will fit in a varchar2(2000). The final parameter passed to the procedure is a Boolean(true/false) that tells the procedure to add this error to the error stack or replace all errors in the stack with this error. Passing the value of 'True' adds the error to the current stack, while the default is 'False'. SQL> create or replace procedure test_var2 (n_test IN number := 0,3 n_result OUthe program. You cannot control when PL/SQL will raise a system exception. You can, however, write code to handle those exceptions when they are raised. The programmer raises a named exception. The programmer can use an explicit call to the RAISE statement to raise a programmer-defined or system-named exception. The programmer raises an unnamed, programmer-defined exception. These are raised with an explicit call to the RAISE_APPLICATION_ERROR procedure in the DBMS_STANDARD package. The programmer re-raises the "current" exception. From within an exception handler, you can re-raise the same exception for propagation to the enclosing block. 8.5.1 Who Raises the Exception? The following sections show how you can let PL/SQL raise a system error or you can check for the error yourself and then raise that same system error. 8.5.1.1 PL/SQL raises ZERO_DIVIDE exception In the following example, I raise my own exception, sales_domination, when the percentage of a customer's sales is over 50% of total sales. If, on the other hand, the total_sales is zero (as will be the case in the senseless code below), PL/SQL will automatically raise the ZERO_DIVIDE exception. Because I include a handler for that specific problem, the application does not abort when this code is executed. Instead, a message is displayed informing the user of a serious problem: DECLARE total_sales NUMBER := 0; cust_sales NUMBER; sales_domination EXCEPTION; BEGIN SELECT SUM (sales) INTO cust_sales FROM invoice WHERE customer_id = 1001; IF cust_sales / total_sales > .5 THEN RAISE sales_domination; END IF; EXCEPTION WHEN ZERO_DIVIDE THEN DBMS_OUTPUT.PUT_LINE (' We haven''t sold anything. We are bankrupt!'); WHEN sales_domination THEN DBMS_OUTPUT.PUT_LINE (' Customer 1001 accounts for more than half of all sales!'); END; Notice that there is no RAISE statement for the ZERO_DIVIDE exception in the body of the program. Instead, I leave it to PL/SQL to raise such internally generated exceptions. There is no restriction, however, on a programmer's raising a predefined exception. 8.5.1.2 Programmer raises ZERO_DIVIDE exception I could recode the previous anonymous block as follows: DECLARE total_sales NUMBER := 0; cust_sales NUMBER; sales_domination EXCEPTION; BEGIN SELECT SUM (sales) INTO cust_sales FROM invoice WHERE customer_id = 1001; /* Check for zero divisor and raise exception if necessary */ IF total