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Pl Sql Error Exception Handling
Table 11-3 lists the names and error codes of the predefined exceptions. This avoids compilation errors. The default exception will be handled using WHEN others THEN: DECLARE BEGIN EXCEPTION WHEN exception1 THEN exception1-handling-statements WHEN exception2 THEN exception2-handling-statements WHEN All Rights Reserved. click site
How Aggregate Result are count against the Governor Limits? All Rights Reserved. And so on down the line. With exception handlers, you need not know every possible error or everywhere that it might occur. https://docs.oracle.com/cd/A97630_01/appdev.920/a96624/07_errs.htm
Pl Sql Exception Handling Examples
For details, see "Error Code and Error Message Retrieval". In the exception-handling part, you can include exception handlers for both specific and unknown errors. b) to make the user-defined exception look like an Oracle error. The pragma must appear somewhere after the exception declaration in the same declarative section, as shown in the following example: DECLARE deadlock_detected EXCEPTION; PRAGMA EXCEPTION_INIT(deadlock_detected, -60); BEGIN ... -- Some operation
You must raise a user-defined exception explicitly. ZERO_DIVIDE 01476 1476 It is raised when an attempt is made to divide a number by zero. The outer block declares the exception, so the exception name exists in both blocks, and each block has an exception handler specifically for that exception. Pl/sql Raises An Exception In Which Two Of The Following Cases These Exceptions have a code and an associated message.
SELECT ... ... For example, if you declare an exception named invalid_number and then PL/SQL raises the predefined exception INVALID_NUMBER internally, a handler written for INVALID_NUMBER will not catch the internal exception. VALUE_ERROR 06502 -6502 It is raised when an arithmetic, conversion, truncation, or size-constraint error occurs. oops:TT0907: Unique constraint (MYTABLE) violated at Rowid select * from mytable; 0 rows found.
Every Oracle error has a number, but exceptions must be handled by name. Which Of The Following Is Not A Type Of Pl/sql Exception Use an error number between -20,000 and -20,999. For more information, see "Internally Defined Exceptions". An internally defined exception does not have a name unless either PL/SQL gives it one (see "Predefined Exceptions") or you give it one.
User Defined Exception In Pl Sql
But remember, an exception is an error condition, not a data item. Place the statement in its own sub-block with its own exception handlers. Pl Sql Exception Handling Examples Scripting on this page enhances content navigation, but does not change the content in any way. Functions For Error Trapping Are Contained In Which Section Of A Pl/sql Block If any other exception was raised, then statements_3 run.
Thus, a block or subprogram can have only one OTHERS handler. http://setiweb.org/pl-sql/pl-sql-exception-error-code.php For the syntax of value_clause, see Oracle Database Reference. However, when an exception is raised inside a cursor FOR loop, the cursor is closed implicitly before the handler is invoked. Raising Internally Defined Exception with RAISE Statement Although the runtime system raises internally defined exceptions implicitly, you can raise them explicitly with the RAISE statement if they have names. Pl Sql Exception Handling Best Practices
That way, an exception handler written for the predefined exception can process other errors, as the following example shows: DECLARE acct_type INTEGER := 7; BEGIN IF acct_type NOT IN (1, 2, If the company has zero earnings, the predefined exception ZERO_DIVIDE is raised. Because a block can reference only local or global exceptions, enclosing blocks cannot reference exceptions declared in a sub-block. navigate to this website For example: DECLARE ex_custom EXCEPTION; BEGIN RAISE ex_custom; EXCEPTION WHEN ex_custom THEN DBMS_OUTPUT.PUT_LINE(SQLERRM); END; / The output is "User-Defined Exception".
The latter are called exceptions. Exception Part Can Be Defined Twice In Same Block For example, the following GOTO statement is illegal: DECLARE pe_ratio NUMBER(3,1); BEGIN DELETE FROM stats WHERE symbol = 'XYZ'; SELECT price / NVL(earnings, 0) INTO pe_ratio FROM stocks WHERE symbol = With PL/SQL, a mechanism called exception handling lets you "bulletproof" your program so that it can continue operating in the presence of errors.
The inner block raises the exception, and its exception handler does the initial handling and then reraises the exception, passing it to the outer block for further handling.
From there on, the exception propagates normally. DECLARE ---------- sub-block begins past_due EXCEPTION; BEGIN ... Example 11-21 Exception Raised in Exception Handler is Handled by Enclosing Block CREATE PROCEDURE descending_reciprocals (n INTEGER) AUTHID DEFINER IS i INTEGER; i_is_one EXCEPTION; BEGIN BEGIN i := n; LOOP IF Exception Handling In Oracle 11g Without exception handlers, you must check for every possible error, everywhere that it might occur, and then handle it.
When the exception hander raises ZERO_DIVIDE, the exception propagates immediately to the invoker. Otherwise, PL/SQL replaces the error stack with error_code. 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 my review here Previous Tutorial: PL/SQL GOTONext Tutorial: PL/SQL Record PL/SQL Quick Start What is PL/SQL PL/SQL Setting Up Basic PL/SQL Tutorial PL/SQL Block Structure PL/SQL Variables PL/SQL Function PL/SQL Procedure PL/SQL Nested Block
BEGIN p(1); END; / Result: Substituting default value for invalid number. For user-defined exceptions, SQLCODE returns +1 and SQLERRM returns the message: User-Defined Exception. If you redeclare a global exception in a sub-block, the local declaration prevails. ora_server_error_depth LOOP dbms_output.put_line(ora_server_error_msg(i) ); END LOOP; dbms_output.put_line( '--------------------' ); END e_trigger; / Simple Error Handling Procedure Function To Identify The User Logged Onto Oracle CREATE OR
Recompile procedure: ALTER PROCEDURE unreachable_code COMPILE; Result: SP2-0805: Procedure altered with compilation warnings Show errors: SHOW ERRORS Result: Errors for PROCEDURE UNREACHABLE_CODE: LINE/COL ERROR -------- ----------------------------------------------------------------- 7/5 PLW-06002: Unreachable code DBMS_WARNING The primary algorithm is not obscured by error recovery algorithms. Typically, you invoke this procedure to raise a user-defined exception and return its error code and error message to the invoker. In the exception-handling part of the sub-block, put an exception handler that rolls back to the savepoint and then tries to correct the problem.
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. There are some system exceptions which are raised frequently, so they are pre-defined and given a name in Oracle which are known as Named System Exceptions. Passing a zero to SQLERRM always returns the message normal, successful completion. When I select everything from the table, it gets that single row with a1 = 1.