Mysql Stored Procedure Error Handling
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to handle exceptions or errors encountered in stored procedures.When an error occurs inside a stored procedure, it is important to handle try catch in mysql stored procedure it appropriately, such as continuing or exiting the current mysql exit handler code block’s execution, and issuing a meaningful error message.MySQL provides an easy way to define
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handlers that handle from general conditions such as warnings or exceptions to specific conditions e.g., specific error codes.Declaring a handlerTo declare a handler, you use
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the DECLARE HANDLER statement as follows: DECLARE action HANDLER FOR condition_value statement;1DECLARE action HANDLER FOR condition_value statement;If a condition whose value matches the condition_value , MySQL will execute the statement and continue or exit the current code block based on the action . The action accepts one of the following mysql declare exit handler values:CONTINUE : the execution of the enclosing code block ( BEGIN … END ) continues.EXIT : the execution of the enclosing code block, where the handler is declared, terminates.The condition_value specifies a particular condition or a class of conditions that activates the handler. The condition_value accepts one of the following values:A MySQL error code.A standard SQLSTATE value. Or it can be an SQLWARNING , NOTFOUND or SQLEXCEPTION condition, which is shorthand for the class of SQLSTATE values. The NOTFOUND condition is used for a cursor or SELECT INTO variable_list statement.A named condition associated with either a MySQL error code or SQLSTATE value.The statement could be a simple statement or a compound statement enclosing by the BEGIN and END keywords.MySQL error handling examplesLet’s look into several examples of declaring handlers.The following handler means that if an error occurs, set the value of the has_error variable to 1 and continue the
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of this site About Us Learn more about Stack Overflow the company mysql stored procedure raise error Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges mysql error handling php Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just like you, helping each other. Join them; it only takes a http://www.mysqltutorial.org/mysql-error-handling-in-stored-procedures/ minute: Sign up MySQL Stored Procedure Error Handling up vote 10 down vote favorite 5 I believe there is nothing currently available in MySQL that allows access to the SQLSTATE of the last executed statement within a MySQL stored procedure. This means that when a generic SQLException is raised within a stored procedure it is hard/impossible to derive the exact nature of http://stackoverflow.com/questions/7764887/mysql-stored-procedure-error-handling the error. Does anybody have a workaround for deriving the SQLSTATE of an error in a MySQL stored procedure that does not involve declaring a handler for every possible SQLSTATE? For example - imagine that I am trying to return an error_status that goes beyond the generic "SQLException happened somewhere in this BEGIN....END block" in the following: DELIMITER $$ CREATE PROCEDURE `myProcedure`(OUT o_error_status varchar(50)) MY_BLOCK: BEGIN DECLARE EXIT handler for 1062 set o_error_status := "Duplicate entry in table"; DECLARE EXIT handler for 1048 set o_error_status := "Trying to populate a non-null column with null value"; -- declare handlers ad nauseum here.... DECLARE EXIT handler for sqlexception set o_error_status:= "Generic SQLException. You'll just have to figure out the SQLSTATE yourself...." ; -- Procedure logic that might error to follow here... END MY_BLOCK$$ Any tips? PS I am running MySQL 5.1.49 mysql stored-procedures error-handling share|improve this question edited Oct 14 '11 at 10:29 asked Oct 14 '11 at 8:19 Tom Mac 6,76621524 add a comment| 3 Answers 3 active oldest votes up vote 6 down vote accepted GET DIAGNOSTICS is available in 5.6.4 See http://dev.mysql.com/doc/refman/5.6/en/get-diagnostics.html share|impr
handling? In the mysql forums, there's been a quite lively discussion regarding how to go about error handling. A quick summary:The MySQL Stored Procedure, trigger and function syntax supports http://rpbouman.blogspot.com/2006/02/dont-you-need-proper-error-handling.html target="_blank">HANDLERs to react to on or more CONDITIONs, should they arise. The syntax and the semantics of these are compliant with the 2003 version of the SQL Standard (this is both an ANSI as well as an ISO standard).A condition can take several forms: it might be:a particular SQLSTATE (these are defined in the SQL Standard)a particular mysql specific error codeone of the predefined stored procedure identifiers for the general conditions: NOT FOUNDSQLEXCEPTION or SQLWARNING the name of a previously declared, user defined condition (right now, a condition declaration must be bound to a SQLSTATE or a mysql specific errorcode, effectively aliasing it)I think the concept of declaring separate handlers for capturing specific error conditions is both powerful and elegant: It allows you to deal with errors in a generic manner, and mysql stored procedure it separates the code that deals with errors entirely from the code that is supposed to do the 'business-as-usual' work. So far, so good. However, just being able to react to errors is not good enough: In order to sucessfully handle the general conditions NOT FOUND, SQLWARNING and SQLEXCEPTION, the handler need to be able to retrieve some details concerning the specific error.One needs to be able to explicitly raise a (user-defined)condition using a special statement When a handler finds it is not suitable to handle the condition fully itself after all, it should be able to pass the condition on to the outer blocks to give other handlers a chanceGetting information on the condition being handledThe lack of this feature has been the subject of questions and confusion in the mysql forums for quite some time, at least as long as I am on them (which is about july 2005 - we're talking mysql 5.0.7 here. There are older ones too: check out this one). Especially when declaring a handler for something as general as SQLEXCEPTION or SQLWARNING, both of which act as a sort of 'wildcard' conditions, one needs to be able to find ou