Hello I have the following stored procedure for MySQL but when it is executed in my ASP.NET Core application I get a Subquery returns more than 1 row error. What am I doing wrong here? The equivalent SQL Server version used to work without problems...
-- System Calculates Candidate’s Matching Score based on a Manager’s Answer Weights
CREATE PROCEDURE spSysCalcCandScore
(
IN Candidate_ID INT,
IN Manager_ID INT
)
Begin
DECLARE ansID INT;
DECLARE tempSum INT;
DECLARE Sum INT;
DECLARE Done INT DEFAULT FALSE;
DECLARE MyCursor CURSOR FOR
SELECT Answer_ID FROM Completed_Questionnaire
WHERE Candidate_ID = Candidate_ID;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET Done = TRUE;
START TRANSACTION;
OPEN MyCursor;
myloop: LOOP
FETCH MyCursor INTO ansID;
IF Done THEN
LEAVE myloop;
END IF;
SET tempSum = (SELECT Weight_Value FROM Weight WHERE (Answer_ID = ansID AND Manager_ID = Manager_ID));
SET Sum = Sum + tempSum;
END LOOP;
CLOSE MyCursor;
IF (Sum IS NULL) THEN
SET Sum = 0;
END IF;
UPDATE `Interest`
SET Matching_Score = Sum
WHERE (Candidate_ID = Candidate_ID AND Manager_ID = Manager_ID);
COMMIT;
End//
I checked the post here and the MySQL manual and I get part of the answer.
Question:
I have some query that can cause errors,, I want to handle them and have a message for the first error happened + line number + rollback (if there is an error).
The part of answer that I have:
Return the code and error message.
Rollback all of the queries if there is an error.
The part of answer that I don't have
The first error (the code return the last error).
Line number.
I know there is some errors in the code because I got each part from one site and mixed them LOL
The codes:
DELIMITER $$
CREATE PROCEDURE prod()
BEGIN
DECLARE is_rolback BOOL DEFAULT 0;
DECLARE resultError TEXT;
DECLARE errorCode CHAR(5) DEFAULT '00000';
DECLARE errorMsg TEXT;
DECLARE ErrorRows INT;
DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
BEGIN
GET DIAGNOSTICS CONDITION 1
errorCode = RETURNED_SQLSTATE, errorMsg = MESSAGE_TEXT;
SET is_rolback = 1;
END;
START TRANSACTION;
SET autocommit = 0;
-- The codes for checking the errors possible
-- Start
insert into table1 values (2, 'B'); -- Correct
insert into table1 values (1, 'A'); -- Error id 1 is already in database;
insert into table1 values ('C'); -- Error should pass also the ID
-- End
IF is_rolback THEN
ROLLBACK;
GET DIAGNOSTICS ErrorRows = ROW_COUNT;
SET resultError = CONCAT('Failed, error = ',errorCode,', line = ', ErrorRows, ', message = ',errorMsg);
select resultError;
select * from table1;
ELSE
COMMIT;
END IF;
END$$
DELIMITER ;
CALL prod();
DROP PROCEDURE IF EXISTS prod;
The output:
Failed, error = 21S01, line = 0, message = Column count doesn't match value count at row 1
id name
1 A
I have created a stored procedure, which should delte data from some tables.
On my productive db I have tables which I have not in my local db (different schema names).
Is there an elegant way to query the data tables existence to avoid exceptions? Maybe declare an error handler which catches the specific error and should continue.
CREATE PROCEDURE `deletion`(IN s_id varchar(255))
BEGIN
DECLARE has_error BOOL DEFAULT FALSE;
/* for all other exception there should be a rollback, if table does not exist
then continue*/
DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET has_error = TRUE;
START TRANSACTION;
DELETE FROM a WHERE id = s_id;
DELETE FROM b WHERE id = s_id;
DELETE FROM c WHERE id = s_id;
DELETE FROM d WHERE id = s_id;
IF has_error THEN
ROLLBACK;
ELSE
COMMIT;
END IF;
END
UPDATE
I tried this, but this is not working. even if the table exists the entry is not deleted:
IF EXISTS (SELECT 1 from information_schema.tables
WHERE table_schema = 'a' ) then
DELETE FROM at WHERE id = s_id;
END IF;
thanks in advance!
I have an organization table that has an id, a parent_id, and a name column. There are roughly 50k rows in this table. There is just one top level parent and the rest are all under that. In Oracle, I am able to easily retrieve the current depth of a particular organization with the level pseudocolumn:
SELECT id, parent_id, level, name
FROM organizations
START WITH parent_id = 1
CONNECT BY PRIOR id = parent_id
I am at a loss of what the proper way to do the above in MySQL is. I need to fetch the entire tree along with the node's depth in one query.
There are a plethora of questions on StackOverflow that have to do with this, but none of them seem to have a really good answer to it, mostly links to blogs with dubious solutions. Surely this is doable in some sort of straight-forward manner?
Unfortunately modifying the table in any way is not an option, so nested sets is not a possibility.
This is totally hilarious. I just picked up a +50 bounty on a similar question literally yesterday : Using MySQL query to traverse rows to make a recursive tree
I referenced how to do this with Stored Procedures in the DBA StackExchange (October 24, 2011)
I will post the same stored procedures along with the examples from my DBA StackExchange answer:
Code to Get the Parent for Any Given Node
DELIMITER $$
DROP FUNCTION IF EXISTS `junk`.`GetParentIDByID` $$
CREATE FUNCTION `junk`.`GetParentIDByID` (GivenID INT) RETURNS INT
DETERMINISTIC
BEGIN
DECLARE rv INT;
SELECT IFNULL(parent_id,-1) INTO rv FROM
(SELECT parent_id FROM pctable WHERE id = GivenID) A;
RETURN rv;
END $$
DELIMITER ;
Code to Get the Ancenstry for Any Given Node
DELIMITER $$
DROP FUNCTION IF EXISTS `junk`.`GetAncestry` $$
CREATE FUNCTION `junk`.`GetAncestry` (GivenID INT) RETURNS VARCHAR(1024)
DETERMINISTIC
BEGIN
DECLARE rv VARCHAR(1024);
DECLARE cm CHAR(1);
DECLARE ch INT;
SET rv = '';
SET cm = '';
SET ch = GivenID;
WHILE ch > 0 DO
SELECT IFNULL(parent_id,-1) INTO ch FROM
(SELECT parent_id FROM pctable WHERE id = ch) A;
IF ch > 0 THEN
SET rv = CONCAT(rv,cm,ch);
SET cm = ',';
END IF;
END WHILE;
RETURN rv;
END $$
DELIMITER ;
Code to Get the Family Tree (or Descendants) for Any Given Node
DELIMITER $$
DROP FUNCTION IF EXISTS `junk`.`GetFamilyTree` $$
CREATE FUNCTION `junk`.`GetFamilyTree` (GivenID INT) RETURNS varchar(1024) CHARSET latin1
DETERMINISTIC
BEGIN
DECLARE rv,q,queue,queue_children VARCHAR(1024);
DECLARE queue_length,front_id,pos INT;
SET rv = '';
SET queue = GivenID;
SET queue_length = 1;
WHILE queue_length > 0 DO
SET front_id = FORMAT(queue,0);
IF queue_length = 1 THEN
SET queue = '';
ELSE
SET pos = LOCATE(',',queue) + 1;
SET q = SUBSTR(queue,pos);
SET queue = q;
END IF;
SET queue_length = queue_length - 1;
SELECT IFNULL(qc,'') INTO queue_children
FROM (SELECT GROUP_CONCAT(id) qc
FROM pctable WHERE parent_id = front_id) A;
IF LENGTH(queue_children) = 0 THEN
IF LENGTH(queue) = 0 THEN
SET queue_length = 0;
END IF;
ELSE
IF LENGTH(rv) = 0 THEN
SET rv = queue_children;
ELSE
SET rv = CONCAT(rv,',',queue_children);
END IF;
IF LENGTH(queue) = 0 THEN
SET queue = queue_children;
ELSE
SET queue = CONCAT(queue,',',queue_children);
END IF;
SET queue_length = LENGTH(queue) - LENGTH(REPLACE(queue,',','')) + 1;
END IF;
END WHILE;
RETURN rv;
END $$
To demonstrate the execution of everything, here is the sample data
USE junk
DROP TABLE IF EXISTS pctable;
CREATE TABLE pctable
(
id INT NOT NULL AUTO_INCREMENT,
parent_id INT,
PRIMARY KEY (id)
) ENGINE=MyISAM;
INSERT INTO pctable (parent_id) VALUES (0);
INSERT INTO pctable (parent_id) SELECT parent_id+1 FROM pctable;
INSERT INTO pctable (parent_id) SELECT parent_id+2 FROM pctable;
INSERT INTO pctable (parent_id) SELECT parent_id+3 FROM pctable;
INSERT INTO pctable (parent_id) SELECT parent_id+4 FROM pctable;
INSERT INTO pctable (parent_id) SELECT parent_id+5 FROM pctable;
SELECT * FROM pctable;
Here is the query to see all Parents, Ancestries, and Family Trees
SELECT
id,parent_id,
GetParentIDByID(id),
GetAncestry(id),
GetFamilyTree(id)
FROM pctable;
Give it a Try !!!
There is no recursion in SQL without CTEs/Subquery Factoring, so there is specifically and absolutely no way to do this with arbitrary level depths in "Pure SQL," especially as implemented in MySQL. See How to transform a MSSQL CTE query to MySQL?
That is why all of the answers you find are hacks, to get around this very specific limitation of the engine. You can try this solution, if you still need one: Generating Depth based tree from Hierarchical Data in MySQL (no CTEs). (Of course, the limitation means that the queries aren't weird to parse, in the LangSec sense, which allows all sorts of beneficial parsing, and eliminates some security concerns, but helps you not at all.)
A bunch of Lefts Joins that exhaust the hierarchy are all you have left, sorry to dissapoint and use a bad pun.
#idok, the function will return "Truncated incorrect DOUBLE value" error if you have same parent id for more than one child, i have found the following fix from dba and it was given by Sivakumar Natarayan
WHILE queue_length > 0 DO
IF queue_length = 1 THEN
SET front_id = queue;
SET queue = '';
ELSE
SET front_id = SUBSTR(queue,1,LOCATE(',',queue)-1);
SET pos = LOCATE(',',queue) + 1;
SET q = SUBSTR(queue,pos);
SET queue = q;
END IF;
Mysql doesn't support recursive sql. When you have only 1 dimension then you can use a Left join with itself on the parent_id = id.
I have this function in my DB
CREATE FUNCTION BookBed (pPaciente varchar(255),
pHospital bigint(20)) RETURNS BOOLEAN
BEGIN
DECLARE NumLeitosDisponiveis INT;
DECLARE vReservaOK BOOLEAN;
DECLARE dt TIMESTAMP;
SET dt = (Select now());
SET NumLeitosDisponiveis = (SELECT AVAILABLEBEDCOUNT FROM HOSPITAL WHERE ID = pHospital);
IF((SELECT NumLeitosDisponiveis) > 0) THEN
BEGIN
START TRANSACTION;
INSERT INTO RESERVATION(PERSON, HOSPITAL, DATE) VALUES (pPaciente, pHospital, dt);
UPDATE HOSPITAL
SET AVAILABLEBEDCOUNT = AVAILABLEBEDCOUNT - 1
WHERE ID = pHospital;
SET vReservaOk = true;
commit;
END;
ELSE
SET vReservaOk = false;
END IF;
RETURN vReservaOK;
END;
In the if part of my if-else statement, I would like to perform all the operations in a atomic way.
I wanted to use the START TRANSACTION command, but they are disallowed in functions and I couldn't find any other command to perform it.
Are functions atomic by default?
If not, is there any way I can implement it?
Thanks,
Oscar
EDIT: And if I have to use a function, is it possible to have transactions?
Use a stored procedure with an output parameter for returning the operation status.
DELIMITER //
CREATE PROCEDURE BookBed (
pPaciente varchar(255),
pHospital bigint(20),
OUT oReservaOK boolean)
BEGIN
DECLARE NumLeitosDisponiveis INT;
DECLARE dt TIMESTAMP;
SET dt = (Select now());
SET NumLeitosDisponiveis =
SELECT AVAILABLEBEDCOUNT FROM HOSPITAL WHERE ID = pHospital;
IF((SELECT NumLeitosDisponiveis) > 0) THEN
BEGIN
START TRANSACTION;
INSERT INTO RESERVATION(PERSON, HOSPITAL, DATE)
VALUES (pPaciente, pHospital, dt);
UPDATE HOSPITAL
SET AVAILABLEBEDCOUNT = AVAILABLEBEDCOUNT - 1
WHERE ID = pHospital;
SET oReservaOk = true;
commit;
END;
ELSE
SET oReservaOk = false;
END IF;
END//
If you are having trouble calling the stored procedure using Hibernate, then move the transaction logic to Hibernate. That is, start, commit or rollback the transaction using Hibernate constructs.
EDIT
Transactions require using the InnoDB engine as #bobobobo notes on the comments.