To use their values in a SQL statement, assign them to local variables first, as in Example 11-11. Exceptions There are three kinds of exceptions Internally defined: A system error, defined by Oracle, that occurs. It is easy to overlook a possible error or a place where it might occur, especially if the error is not immediately detectable (for example, bad data might be undetectable until The outer block handles the exception with an OTHERS exception handler. this page
CURSOR_ALREADY_OPEN Your program attempts to open an already open cursor. That is, the built-in parameter SELF (which is always the first parameter passed to a MEMBER method) is null. If the transaction succeeds, commit, then exit from the loop.
Raise an exception in a PL/SQL block or subprogram only when an error makes it undesirable or impossible to finish processing. 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 Test your code with different combinations of bad input data to see what potential errors arise. Pl Sql Exception When Others Tips for Handling PL/SQL Errors In this section, you learn three techniques that increase flexibility.
Expect that at some time, your code will be passed incorrect or null parameters, that your queries will return no rows or more rows than you expect. Raise Application Error Oracle Example To reraise an exception, simply place a RAISE statement in the local handler, as shown in the following example: DECLARE out_of_balance EXCEPTION; BEGIN ... 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. https://docs.oracle.com/cd/A97630_01/appdev.920/a96624/07_errs.htm Some common internal exceptions have predefined names, such as ZERO_DIVIDE and STORAGE_ERROR.
Therefore, a PL/SQL block cannot handle an exception raised by a remote subprogram. Functions For Error Trapping Are Contained In Which Section Of A Pl/sql Block All legitimate Oracle experts publish their Oracle qualifications. Predefined PL/SQL Exceptions An internal exception is raised automatically if your PL/SQL program violates a database rule or exceeds a system-dependent limit. Unlike variables, exceptions cannot appear in assignment statements or SQL statements.
EXCEPTION WHEN OTHERS THEN log_error($$PLSQL_UNIT,$$PLSQL_LINE,p_param1,p_param2); RAISE; END; The “log_error”-procedure defined as autonomous transaction, writing the information we need for troubleshooting to a table. useful reference An exception name declaration has this syntax: exception_name EXCEPTION; For semantic information, see "Exception Declaration". Pl Sql Exception Handling Examples Reraising the exception passes it to the enclosing block, which can handle it further. (If the enclosing block cannot handle the reraised exception, then the exception propagates—see "Exception Propagation".) When reraising User Defined Exception In Pl Sql Oracle allows us the create error numbers in the range of -20000 to -20999.
Retrying a Transaction After an exception is raised, rather than abandon your transaction, you might want to retry it. this website You cannot use SQLCODE or SQLERRM directly in a SQL statement. You need only include an exception-handling part in each block where errors might occur. exception when connection_error then ... Pl Sql Exception Handling Continue Loop
The optional OTHERS exception handler, which is always the last handler in a block or subprogram, acts as the handler for all exceptions not named specifically. Within this handler, you can invoke the functions SQLCODE and SQLERRM to return the Oracle Database error code and message text. The 22 predefined exceptions also have a name assigned, which allows for easier, and more readable exception handling. http://back2cloud.com/pl-sql/pl-sql-return-error-code.php THEN RAISE out_of_balance; -- raise the exception END IF; EXCEPTION WHEN out_of_balance THEN -- handle the error RAISE; -- reraise the current exception END; ------------ sub-block ends EXCEPTION WHEN out_of_balance THEN
LOGIN_DENIED 01017 -1017 A program attempts to log on to the database with an invalid username or password. Pl Sql Exception Handling Best Practices If the transaction succeeds, commit, then exit from the loop. If you redeclare a global exception in a sub-block, the local declaration prevails.
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'); Go to main content 18/99 The script content on this page is for navigation purposes only and does not alter the content in any way. 11 PL/SQL Error Handling This chapter Guidelines for Handling PL/SQL Errors Topics: Continuing Execution After an Exception Is Raised Retrying a Transaction Using Locator Variables to Identify Exception Locations Continuing Execution After an Exception Is Raised An Pl/sql Raises An Exception In Which Two Of The Following Cases After the exception handler runs, control transfers to the host environment.
To refer to all warning messages, use the keyword All. To have the enclosing block handle the raised exception, you must remove its declaration from the sub-block or define an OTHERS handler. You can also subscribe without commenting. see here DECLARE default_number NUMBER := 0; BEGIN INSERT INTO t VALUES(TO_NUMBER('100.00', '9G999')); EXCEPTION WHEN INVALID_NUMBER THEN DBMS_OUTPUT.PUT_LINE('Substituting default value for invalid number.'); INSERT INTO t VALUES(default_number); END; / Result: Substituting default value
Use error-checking code wherever bad input data can cause an error. This stops normal execution of the block and transfers control to the exception handlers. Just like we did for system errors, we can name our user defined errors by using the pragma “EXCEPTION_INIT”. How to add non-latin entries in hosts file What game is this picture showing a character wearing a red bird costume from?
Passing a VARCHAR2 value to a NUMBER column in an INSERT statement INFORMATIONAL Condition does not affect performance or correctness, but you might want to change it to make the code You can suppress or display groups of similar warnings during compilation. Example 11-12 Raising User-Defined Exception with RAISE_APPLICATION_ERROR CREATE PROCEDURE account_status ( due_date DATE, today DATE ) AUTHID DEFINER IS BEGIN IF due_date < today THEN -- explicitly raise exception RAISE_APPLICATION_ERROR(-20000, 'Account asked 4 years ago viewed 5281 times active 4 years ago Related 11How to catch and handle only specific Oracle exceptions?1oracle - does this have the potential to cause a lock?5One
That is, normal execution stops and control transfers to the exception-handling part of your PL/SQL block or subprogram. Aliasing problems with parameters PERFORMANCE Condition might cause performance problems. END; / See Also: "Raising Internally Defined Exception with RAISE Statement" Predefined Exceptions Predefined exceptions are internally defined exceptions that have predefined names, which PL/SQL declares globally in the package STANDARD. Make the last statement in the OTHERS exception handler either RAISE or an invocation of the RAISE_APPLICATION_ERROR procedure. (If you do not follow this practice, and PL/SQL warnings are enabled, then
If the optional third parameter is TRUE, the error is placed on the stack of previous errors. SUBSCRIPT_OUTSIDE_LIMIT Your program references a nested table or varray element using an index number (-1 for example) that is outside the legal range.