I am running a MySQL Query. But when a new row is added from form input I get this error:
Error: Can't update table 'brandnames' in stored function/trigger because it is
already used by statement which invoked this stored function/trigger.
From the code:
CREATE TRIGGER `capital` AFTER INSERT ON `brandnames`
FOR EACH
ROW UPDATE brandnames
SET bname = CONCAT( UCASE( LEFT( bname, 1 ) ) , LCASE( SUBSTRING( bname, 2 ) ) )
What does this error mean?
You cannot change a table while the INSERT trigger is firing. The INSERT might do some locking which could result in a deadlock. Also, updating the table from a trigger would then cause the same trigger to fire again in an infinite recursive loop. Both of these reasons are why MySQL prevents you from doing this.
However, depending on what you're trying to achieve, you can access the new values by using NEW.fieldname or even the old values --if doing an UPDATE-- with OLD.
If you had a row named full_brand_name and you wanted to use the first two letters as a short name in the field small_name you could use:
CREATE TRIGGER `capital` BEFORE INSERT ON `brandnames`
FOR EACH ROW BEGIN
SET NEW.short_name = CONCAT(UCASE(LEFT(NEW.full_name,1)) , LCASE(SUBSTRING(NEW.full_name,2)))
END
The correct syntax is:
FOR EACH ROW SET NEW.bname = CONCAT( UCASE( LEFT( NEW.bname, 1 ) )
, LCASE( SUBSTRING( NEW.bname, 2 ) ) )
A "BEFORE-INSERT"-trigger is the only way to realize same-table updates on an insert, and is only possible from MySQL 5.5+. However, the value of an auto-increment field is only available to an "AFTER-INSERT" trigger - it defaults to 0 in the BEFORE-case. Therefore the following example code which would set a previously-calculated surrogate key value based on the auto-increment value id will compile, but not actually work since NEW.id will always be 0:
create table products(id int not null auto_increment, surrogatekey varchar(10), description text);
create trigger trgProductSurrogatekey before insert on product
for each row set NEW.surrogatekey =
(select surrogatekey from surrogatekeys where id = NEW.id);
#gerrit_hoekstra wrote: "However, the value of an auto-increment field is only available to an "AFTER-INSERT" trigger - it defaults to 0 in the BEFORE-case."
That is correct but you can select the auto-increment field value that will be inserted by the subsequent INSERT quite easily. This is an example that works:
CREATE DEFINER = CURRENT_USER TRIGGER `lgffin`.`variable_BEFORE_INSERT` BEFORE INSERT
ON `variable` FOR EACH ROW
BEGIN
SET NEW.prefixed_id = CONCAT(NEW.fixed_variable, (SELECT `AUTO_INCREMENT`
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = 'lgffin'
AND TABLE_NAME = 'variable'));
END
I have the same problem and fix by add "new." before the field is updated. And I post full trigger here for someone to want to write a trigger
DELIMITER $$
USE `nc`$$
CREATE
TRIGGER `nhachung_province_count_update` BEFORE UPDATE ON `nhachung`
FOR EACH ROW BEGIN
DECLARE slug_province VARCHAR(128);
DECLARE slug_district VARCHAR(128);
IF old.status!=new.status THEN /* neu doi status */
IF new.status="Y" THEN
UPDATE province SET `count`=`count`+1 WHERE id = new.district_id;
ELSE
UPDATE province SET `count`=`count`-1 WHERE id = new.district_id;
END IF;
ELSEIF old.province_id!=new.province_id THEN /* neu doi province_id + district_id */
UPDATE province SET `count`=`count`+1 WHERE id = new.province_id; /* province_id */
UPDATE province SET `count`=`count`-1 WHERE id = old.province_id;
UPDATE province SET `count`=`count`+1 WHERE id = new.district_id; /* district_id */
UPDATE province SET `count`=`count`-1 WHERE id = old.district_id;
SET slug_province = ( SELECT slug FROM province WHERE id= new.province_id LIMIT 0,1 );
SET slug_district = ( SELECT slug FROM province WHERE id= new.district_id LIMIT 0,1 );
SET new.prov_dist_url=CONCAT(slug_province, "/", slug_district);
ELSEIF old.district_id!=new.district_id THEN
UPDATE province SET `count`=`count`+1 WHERE id = new.district_id;
UPDATE province SET `count`=`count`-1 WHERE id = old.district_id;
SET slug_province = ( SELECT slug FROM province WHERE id= new.province_id LIMIT 0,1 );
SET slug_district = ( SELECT slug FROM province WHERE id= new.district_id LIMIT 0,1 );
SET new.prov_dist_url=CONCAT(slug_province, "/", slug_district);
END IF;
END;
$$
DELIMITER ;
Hope this help someone
Summary: I am trying to add a Username to the db.username_table with a unique ID incremented by 1. However, I keep receiving an error 1111 related to my CASE statement. It should make the first User_ID 1, then all other new ones the max(user_id) +1. Any help would be greatly appreciated!
Background: This is for my first MySQL project - I have some experience with MS SQL that may be hindering me here. I googled many references and streamlined my code as much as possible, but the aggregate for the counter returns a 1111 error with an IF or with a CASE statement.
DELIMITER $$
CREATE PROCEDURE db.add_user
(
in new_username varchar(45)
)
begin
-- Set Counter ID
declare new_user_id int;
set new_user_id = if(max(db.username_table.User_ID) is null, 1, max(db.username_table.User_ID) + 1);
-- Add Username with Counter
insert into db.username_table (user_id, username)
values (new_user_id, new_username);
END$$
DELIMITER ;
Expected Result - Add a Username to the db.username_table with a unique ID incremented by 1.
Actual Result - Error 1111.
You are using the funtion MAX but not in SQL statements .. so the max of is used improperly . you need a select for retrive a MAX(db.username_table.User_ID.)
declare new_user_id int;
select case when
max(ifnull(db.username_table.User_ID,0)) = 0
then 1
else max(db.username_table.User_ID) + 1 end
INTO new_user_id
from your_table ;
but could you simply need an autoincrement column for User_id and avoid this SP
CREATE TABLE your_table (
User_ID int(11) NOT NULL AUTO_INCREMENT,
....
)
I would like to capture the primary key value of column based on the last inserted record. Below is the table structure:
create table test
(
id varchar(100) not null primary key,
rmain varchar(100),
rpart bigint
);
Stored Procedure:
Delimiter $$
DROP PROCEDURE IF EXISTS insTest$$
Create Procedure insTest()
Begin
Set #rmain := (select trim(concat('DNB', DATE_FORMAT(CURRENT_DATE(), '%y'), DATE_FORMAT(CURRENT_DATE(), '%m'))));
IF ((trim(DATE_FORMAT(CURRENT_DATE(),'%m')) = 01) OR (trim(DATE_FORMAT(CURRENT_DATE(),'%m')) = 1)) THEN
Set #rpart = 1;
END IF;
IF ((trim(DATE_FORMAT(CURRENT_DATE(),'%m')) != 01) OR (trim(DATE_FORMAT(CURRENT_DATE(),'%m')) != 1)) THEN
Set #rpart := (select coalesce(max(rpart),0) from test) + 1;
END IF;
insert into Test (ID, rmain, rpart) values (concat(#rmain,#rpart),#rmain,#rpart);
End$$
DELIMITER ;
Please advice. I checked on last_insert_ID() but it works for primary key column with auto_increment setting only. Thanks in advance...
Why? What if you get select max(id) or if you get select id from tbl1 order by id desc limit 1?
See Transaction In MySQL. Also, set the transaction isolation level to READ COMMITTED
declare last_id INT;
START TRANSACTION;
INSERT INTO tbl1(id,col1,col2) values(1001,'test','test');
SELECT last_id = id FROM tbl1 ORDER BY id DESC LIMIT 1
COMMIT;
INSERT INTO test (a,b,c) values (1,2,3);
SELECT LAST_INSERT_ID();
this way you can access the last inserted id
I have a table which contains header information for transactions. The transactions belong to different projects.
In the header I have columns:
rhguid - uniqueidentifier
rhserial - int
rh_projectID - int
First I insert the row (there's more columns)
Then I calculate the serial number for that project:
update responseheader
set rhSerial = 1 + (select isnull(max(rhSerial), 0)
from responseheader
where (rhstatus = 0) AND (rh_projectID = 1234))
where
(rhGUID = <preassignedGUID>);
However when there are many transactions happening at the same time for a project I am finding duplicate rhserial values.
I'm doing this in classic ASP with SQL Server 2008.
Is there a better way?
From your example, it doesn't look like you're using a transaction. My guess is that the SELECT portion of the statement is running as READ UNCOMMITTED, otherwise you would not see duplicates. There are ways to start transactions with ADO, but I prefer using stored procedures instead.
Try implementing something like this:
CREATE PROC dbo.ResponseHeader_Insert
<more data to insert>,
#ProjectID INT,
#Status SMALLINT
as
insert responseheader (column names here)
select <param values here>, isnull(max(rhSerial), 0) + 1
from responseheader
where (rhstatus = #Status) AND (rh_projectID = #ProjectID))
If this doesn't work for ya, try creating sequence tables (one for each sequence).
create table <tablename> (
SeqID int identity(1,1) primary key,
SeqVal varchar(1)
)
Create a procedure to get the next identity:
create procedure GetNewSeqVal_<tablename>
as
begin
declare #NewSeqValue int
set NOCOUNT ON
insert into <tablename> (SeqVal) values ('a')
set #NewSeqValue = scope_identity()
delete from <tablename> WITH (READPAST)
return #NewSeqValue
end
If there are too many sequence tables that need to be created or you want to create sequences on the fly, try this approach:
Create table AllSequences (
SeqName nvarchar(255) primary key, -- name of the sequence
Seed int not null default(1), -- seed value
Incr int not null default(1), -- incremental
Currval int
)
Go
create procedure usp_CreateNewSeq
#SeqName nvarchar(255),
#seed int = 0,
#incr int = 1
as
begin
declare #currval int
if exists (
select 1 from AllSequences
where SeqName = #SeqName )
begin
print 'Sequence already exists.'
return 1
end
if #seed is null set #seed = 1
if #incr is null set #incr = 1
set #currval = #seed
insert into AllSequences (SeqName, Seed, Incr, CurrVal)
values (#SeqName, #Seed, #Incr, #CurrVal)
end
go
create procedure usp_GetNewSeqVal
#SeqName nvarchar(255)
as
begin
declare #NewSeqVal int
set NOCOUNT ON
update AllSequences
set #NewSeqVal = CurrVal = CurrVal+Incr
where SeqName = #SeqName
if ##rowcount = 0 begin
print 'Sequence does not exist'
return
end
return #NewSeqVal
end
go
I'm stuck here.
I've got a Procedure that I want to run X* times in a row. (*X is couple of thousands times)
The procedure based on input data does this:
1. Looks for an actions.id, if not found LEAVEs.
2. Looks for users.id, if not found, creates one and uses LAST_INSERT_ID();
3-5. Looks for summaries.id (3 types, total, daily and monthly), if not found, creates one and uses it's ID.
6. Once all required ids are collected, INSERTs new row into actions and either updates the summaries rows in a transaction, so if any fails - it does a ROLLBACK - no harm done.
7. Depending on the outcome SELECTs message.
CREATE PROCEDURE NEW_ACTION(
IN a_date TIMESTAMP,
IN u_name VARCHAR(255),
IN a_name VARCHAR(255),
IN a_chars INT,
IN url VARCHAR(255),
IN ip VARCHAR(15))
lbl_proc: BEGIN
DECLARE a_id, u_id, us_id, usd_id, usm_id, a_day, a_month, error INT;
DECLARE CONTINUE HANDLER FOR SQLSTATE '23000' SET error = 1;
SET error = 0;
SET a_day = DATE_FORMAT(SUBSTRING(a_date ,1,10), '%Y%m%d');
SET a_month = SUBSTRING(a_day, 1, 6);
/* 1. RETREIVING action.id */
SET a_id = (SELECT `id` FROM `actions` WHERE `name` = a_name);
IF a_id IS NULL THEN
SELECT 'error';
LEAVE lbl_proc;
END IF;
/* 2. RETREIVING users.id */
SET u_id = (SELECT `id` FROM `users` WHERE `name` = u_name);
IF u_id IS NULL THEN
INSERT INTO `users` (name) VALUES (u_name);
SET u_id = (SELECT LAST_INSERT_ID());
END IF;
/* 3. RETREIVING user_summaries.id */
SET us_id = (SELECT `id` FROM `users_summaries` WHERE `user_id` = u_id AND `action_id` = a_id);
IF us_id IS NULL THEN
INSERT INTO `users_summaries` (user_id, action_id) VALUES (u_id, a_id);
SET us_id = (SELECT LAST_INSERT_ID());
END IF;
/* 4. RETREIVING user_summaries_days.id */
SET usd_id = (SELECT `id` FROM `users_summaries_days` WHERE `day` = a_day AND `user_id` = u_id AND `action_id` = a_id);
IF usd_id IS NULL THEN
INSERT INTO `users_summaries_days` (day, user_id, action_id) VALUES (a_day, u_id, a_id);
SET usd_id = (SELECT LAST_INSERT_ID());
END IF;
/* 5. RETREIVING user_summaries_months.id */
SET usm_id = (SELECT `id` FROM `users_summaries_months` WHERE `month` = a_month AND `user_id` = u_id AND `action_id` = a_id);
IF usm_id IS NULL THEN
INSERT INTO `users_summaries_months` (month, user_id, action_id) VALUES (a_month, u_id, a_id);
SET usm_id = (SELECT LAST_INSERT_ID());
END IF;
/* 6. SAVING action AND UPDATING summaries */
SET autocommit = 0;
START TRANSACTION;
INSERT INTO `users_actions` (`date`, `user_id`, `action_id`, `chars`, `url`, `ip`) VALUES (a_date, u_id, a_id, a_chars, url, ip);
UPDATE `users_summaries` SET qty = qty + 1, chars = chars + a_chars WHERE id = us_id;
UPDATE `users_summaries_days` SET qty = qty + 1, chars = chars + a_chars WHERE id = usd_id;
UPDATE `users_summaries_months` SET qty = qty + 1, chars = chars + a_chars WHERE id = usm_id;
IF error = 1 THEN
SELECT 'error';
ROLLBACK;
LEAVE lbl_proc;
ELSE
SELECT 'success';
COMMIT;
END IF;
END;
Now, I've got raw data that I want to feed into this procedure. There's currently about 3000 rows.
I tried all the solutions I knew:
A. # mysql -uuser -ppass DB < calls.sql - Using php I've basically created a list of calls like this:
CALL NEW_ACTION('2010-11-01 13:23:00', 'username1', 'actionname1', '100', 'http://example.com/', '0.0.0.0');
CALL NEW_ACTION('2010-11-01 13:23:00', 'username2', 'actionname1', '100', 'http://example.com/', '0.0.0.0');
CALL NEW_ACTION('2010-11-01 13:23:00', 'username1', 'actionname2', '100', 'http://example.com/', '0.0.0.0');
...
This fails always (tried few times) at row 452 where it found two summary IDs (step 3).
I thought this could be due to the fact that earlier (rows 375-376) there are calls for the same user for the same action.
As if mysql didn't update tables in time, so the summary row created in CALL from line 375 isn't yet visible when line 376 gets executed - therefore creating another summary line.
Tought I'd try delaying calls...
B. Using mysql's SLEEP(duration).
This didn't change anything. Execution stops at the very same CALL again.
I'm out of ideas now.
Suggestions and help hugely appreciated.
NOTE: action names and user names repeat.
PS. Bear in mind this is one of my first procedures ever written.
PS2. Running mysql 5.1.52-community-log 64bit (Windows 7U), PHP 5.3.2 and Apache 2.2.17
EDIT
I've removed PHP related part of question to a separate question here.
EDIT2
Ok, I've deleted the first 200 calls from the .sql file. For some reason it went fine past the previous line that was stopping execution. Now it stopped at row 1618.
This would mean, that at one point a newly INSERTed summary row is no visible for a moment, therefore when it happens that one of the following iterations want to SELECT it, it's not yet accessible for them. Is that a MySQL bug?
EDIT3
Now there's another interesting thing I noticed. I investigated where two users_summaries get created. This happens (not always, but if, then it is) when there are two CALLs referring to the same user and action in close proximity. They could be next to each other or separated by 1 or 2 different calls.
If I move one of them (within .sql file) like 50-100 rows lower (executed earlier) than it's fine. I even managed to make the .sql file work as a whole. But this still doesn't really solve the problem. With 3000 rows it's not that bad, but if I had 100000, I'm lost. I can't rely on manual tweaks to .sql file.
This isn't really a solution, but a workaround.
Just to clarify, summary tables had id column as PRIMARY KEY with AUTO_INCREMENT option and indexes on both user_id and action_id column.
My investigation showed that although my procedure was looking for an entry that existed using WHERE user_id = u_id AND action_id = a_id in certain situations it didn't find it causing new row being inserted with the same user_id and action_id values - something I did not want.
Debugging the procedure showed that the summary row I was looking for, although not accessible with WHERE user_id = u_id AND action_id = a_id condition, was properly returned when calling it's id - PRIMARY KEY.
With this find I decided to change format of id column, from UNASIGNED INT with AUTO_INCEREMENT to a CHAR(32) which consisted of:
<user_id>|<action_id>
This meant that I knew exactly what the id of the row I wanted is even before it existed. This solved the problem really. It also enabled me to use INSERT ... ON DUPLICATE KEY UPDATE ... construct.
Below my updated procedure:
CREATE PROCEDURE `NEW_ACTION`(
IN a_date TIMESTAMP,
IN u_name VARCHAR(255),
IN a_name VARCHAR(255),
IN a_chars INT,
IN url VARCHAR(255),
IN ip VARCHAR(15))
SQL SECURITY INVOKER
lbl_proc: BEGIN
DECLARE a_id, u_id, a_day, a_month, error INT;
DECLARE us_id, usd_id, usm_id CHAR(48);
DECLARE sep CHAR(1);
DECLARE CONTINUE HANDLER FOR SQLSTATE '23000' SET error = 1;
SET sep = '|';
SET error = 0;
SET a_day = DATE_FORMAT(SUBSTRING(a_date ,1,10), '%Y%m%d');
SET a_month = SUBSTRING(a_day, 1, 6);
/* RETREIVING action.id */
SET a_id = (SELECT `id` FROM `game_actions` WHERE `name` = a_name);
IF a_id IS NULL THEN
SELECT 'error';
LEAVE lbl_proc;
END IF;
/* RETREIVING users.id */
SET u_id = (SELECT `id` FROM `game_users` WHERE `name` = u_name);
IF u_id IS NULL THEN
INSERT INTO `game_users` (name) VALUES (u_name);
SET u_id = LAST_INSERT_ID();
END IF;
/* SETTING summaries ids */
SET us_id = CONCAT(u_id, sep, a_id);
SET usd_id = CONCAT(a_day, sep, u_id, sep, a_id);
SET usm_id = CONCAT(a_month, sep, u_id, sep, a_id);
/* SAVING action AND UPDATING summaries */
SET autocommit = 0;
START TRANSACTION;
INSERT INTO `game_users_actions` (`date`, `user_id`, `action_id`, `chars`, `url`, `ip`)
VALUES (a_date, u_id, a_id, a_chars, url, ip);
INSERT INTO `game_users_summaries` (`id`, `user_id`, `action_id`, `qty`, `chars`)
VALUES (us_id, u_id, a_id, 1, a_chars)
ON DUPLICATE KEY UPDATE qty = qty + 1, chars = chars + a_chars;
INSERT INTO `game_users_summaries_days` (`id`, `day`, `user_id`, `action_id`, `qty`, `chars`)
VALUES (usd_id, a_day, u_id, a_id, 1, a_chars)
ON DUPLICATE KEY UPDATE qty = qty + 1, chars = chars + a_chars;
INSERT INTO `game_users_summaries_months` (`id`, `month`, `user_id`, `action_id`, `qty`, `chars`)
VALUES (usm_id, a_month, u_id, a_id, 1, a_chars)
ON DUPLICATE KEY UPDATE qty = qty + 1, chars = chars + a_chars;
IF error = 1 THEN
SELECT 'error';
ROLLBACK;
LEAVE lbl_proc;
ELSE
SELECT 'success';
COMMIT;
END IF;
END
Anyway, I still think there's some kind of a bug in MySQL, but I consider problem solved.