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Pl Sql Error Handling Exception


When the sub-block ends, the enclosing block continues to execute at the point where the sub-block ends. With many programming languages, unless you disable error checking, a run-time error such as stack overflow or division by zero stops normal processing and returns control to the operating system. WHEN OTHERS THEN -- handles all other errors ROLLBACK; END; -- exception handlers and block end here The last example illustrates exception handling, not the effective use of INSERT statements. The procedure compiles without warnings. click site

Whenever an exception occurs, it is raised. Just e-mail: and include the URL for the page. PL/SQL procedure successfully completed. The following example illustrates the programmer-defined exceptions. https://docs.oracle.com/cd/A97630_01/appdev.920/a96624/07_errs.htm

Pl Sql Exception Handling Examples

Example 11-22 Displaying SQLCODE and SQLERRM Values DROP TABLE errors; CREATE TABLE errors ( code NUMBER, message VARCHAR2(64) ); CREATE OR REPLACE PROCEDURE p AUTHID DEFINER AS name EMPLOYEES.LAST_NAME%TYPE; v_code NUMBER; After the exception handler runs, control transfers to the host environment. The outer block does not have an exception handler for C, so PL/SQL returns an unhandled exception error to the host environment.

Example 11-2 uses an ALTER SESSION statement to disable all warning messages for the session and then compiles a procedure that has unreachable code. Handling Exceptions Raised in Declarations Exceptions can be raised in declarations by faulty initialization expressions. Handling Raised PL/SQL Exceptions When an exception is raised, normal execution of your PL/SQL block or subprogram stops and control transfers to its exception-handling part, which is formatted as follows: EXCEPTION Functions For Error Trapping Are Contained In Which Section Of A Pl/sql Block END; In this example, if the SELECT INTO statement raises a ZERO_DIVIDE exception, the local handler catches it and sets pe_ratio to zero.

In procedural statements, VALUE_ERROR is raised if the conversion of a character string into a number fails. (In SQL statements, INVALID_NUMBER is raised.) ZERO_DIVIDE A program attempts to divide How Can A User Defined Exception Be Raised INVALID_CURSOR Your program attempts an illegal cursor operation such as closing an unopened cursor. In the following example, if the SELECT INTO statement raises ZERO_DIVIDE, you cannot resume with the INSERT statement: DECLARE pe_ratio NUMBER(3,1); BEGIN DELETE FROM stats WHERE symbol = 'XYZ'; SELECT price i thought about this A user-defined exception must be declared and then raised explicitly, using either a RAISE statement or the procedure DBMS_STANDARD.RAISE_APPLICATION_ERROR.

So, an exception raised inside a handler propagates immediately to the enclosing block, which is searched to find a handler for the newly raised exception. Pl/sql Raises An Exception In Which Two Of The Following Cases With PL/SQL, a mechanism called exception handling lets you "bulletproof" your program so that it can continue operating in the presence of errors. Exceptions can be internally defined (by the run-time system) or user defined. Since there is no customer with ID value 8 in our database, the program raises the run-time exception NO_DATA_FOUND, which is captured in EXCEPTION block.

How Can A User Defined Exception Be Raised

Some common internal exceptions have predefined names, such as ZERO_DIVIDE and STORAGE_ERROR. https://www.tutorialspoint.com/plsql/plsql_exceptions.htm For user-defined exceptions, SQLCODE returns +1 and SQLERRM returns the message: User-Defined Exception. Pl Sql Exception Handling Examples With this technique, you should use a FOR or WHILE loop to limit the number of attempts. Pl Sql Exception Handling Continue Loop These Exceptions have a code and an associated message.

Example 11-25 Retrying Transaction After Handling Exception DROP TABLE results; CREATE TABLE results ( res_name VARCHAR(20), res_answer VARCHAR2(3) ); CREATE UNIQUE INDEX res_name_ix ON results (res_name); INSERT INTO results (res_name, res_answer) http://setiweb.org/pl-sql/pl-sql-exception-error-code.php The following example shows how exceptions are trapped using the appropriate exception handler. If you redeclare a global exception in a sub-block, the local declaration prevails. Tips for Handling PL/SQL Errors In this section, you learn three techniques that increase flexibility. Pl Sql Exception Handling Best Practices

The technique is: Encase the transaction in a sub-block. NO_DATA_FOUND 01403 +100 It is raised when a SELECT INTO statement returns no rows. Example 11-24 Exception Handler Runs and Execution Continues DECLARE sal_calc NUMBER(8,2); BEGIN INSERT INTO employees_temp (employee_id, salary, commission_pct) VALUES (301, 2500, 0); BEGIN SELECT (salary / commission_pct) INTO sal_calc FROM employees_temp navigate to this website In the following example, if the SELECT INTO statement raises ZERO_DIVIDE, you cannot resume with the INSERT statement: DECLARE pe_ratio NUMBER(3,1); BEGIN DELETE FROM stats WHERE symbol = 'XYZ'; SELECT price

To call RAISE_APPLICATION_ERROR, use the syntax raise_application_error(error_number, message[, {TRUE | FALSE}]); where error_number is a negative integer in the range -20000 .. -20999 and message is a character string up to Exception Part Can Be Defined Twice In Same Block Though they share the same name, the two past_due exceptions are different, just as the two acct_num variables share the same name but are different variables. A cursor must be closed before it can be reopened.

EXCEPTION_INIT will associate a predefined Oracle error number to a programmer_defined exception name.

In the example below, you calculate and store a price-to-earnings ratio for a company with ticker symbol XYZ. unless you used the pragma EXCEPTION_INIT to associate the exception name with an Oracle error number, in which case SQLCODE returns that error number and SQLERRM returns the corresponding error message. If the salary is above the range, we raise the exception ABOVE_SALARY_RANGE just make it simple for demonstration. In Which Section Are Exception Raised You can find the value of this parameter by issuing SHOW PARAMETER USER_DUMP_DEST.

If you know that your database operations might raise specific internally defined exceptions that do not have names, then give them names so that you can write exception handlers specifically for The results were that everything was stored in the table except the 'bad' lines. Home Book List Contents Index Master Index Feedback Go to main content 18/99 The script content on this page is for navigation purposes only and does not alter the content in my review here For more information, see "Internally Defined Exceptions".

Because a block can reference only local or global exceptions, enclosing blocks cannot reference exceptions declared in a sub-block. Normally, just the failed SQL statement is rolled back, not the whole transaction. Figure 11-1 Exception Does Not Propagate Description of "Figure 11-1 Exception Does Not Propagate" In Figure 11-2, the inner block raises exception B. Errors are especially likely during arithmetic calculations, string manipulation, and database operations.

nvl(l_text.count,0) LOOP dbms_output.put_line(l_text(i) ); END LOOP; dbms_output.put_line( 'error text: ' ); FOR i IN 1 .. Therefore, the values of explicit cursor attributes are not available in the handler. In Example 11-20, the exception-handling part of the procedure has exception handlers for user-defined exception i_is_one and predefined exception ZERO_DIVIDE. You declare an exception by introducing its name, followed by the keyword EXCEPTION.

SELECT ... ... Example 11-18 Exception Raised in Exception Handler is Handled by Invoker CREATE PROCEDURE print_reciprocal (n NUMBER) AUTHID DEFINER IS BEGIN DBMS_OUTPUT.PUT_LINE(1/n); EXCEPTION WHEN ZERO_DIVIDE THEN DBMS_OUTPUT.PUT_LINE('Error:'); DBMS_OUTPUT.PUT_LINE(1/n || ' is undefined'); You can make the checking as general or as precise as you like.