I have a table for an event, and I have just made a new table for ticketing_information. Each event in the event table should have a ticketing_information, referenced by a unique id. I'm new to sql, so forgive me if this is a very basic/repeated question, but how should I go about making the migration add a new row to the ticketing_information table for every existing event, and giving the event the generated ticketing_information id?
If it helps, some of my sql is attached:
CREATE TABLE `ticketing_information` (
`id` INT(10) unsigned NOT NULL AUTO_INCREMENT,
`tickets_available` BOOLEAN DEFAULT TRUE NOT NULL,
`ticketing_url` VARCHAR(2000) DEFAULT NULL,
`additional_info_url` VARCHAR(2000) DEFAULT NULL,
PRIMARY KEY (`id`);)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8;
ALTER TABLE event
ADD COLUMN ticketing_information_id Int(10) unsigned DEFAULT NULL;
(This is a very stripped-down version of the code, but it should help illustrate the behavior I want)
I was thinking it should be something along the lines of
UPDATE event SET
ticketing_information_id = SELECT `id` FROM `ticketing_information` WHERE <some way of making a new ticketing_information?>;
But I don't really know what I'm doing :)
how i would perform something like, adding a new non-nullable column to an existing table, would be:
adding that column in first step as nullable, otherwise you will not get the rdbms to modify the table, because it will violate the not null constraint.
updating the new column to the data you want it to have
UPDATE event e
SET e.ticketing_information_id = (SELECT `id` FROM `ticketing_information` WHERE id = e.id)
Your update needs to tell the inner select, which row it is currently updating, so you are able to filter only the data of that particular row in the inner select.
modifying the column to be not null
Related
I am trying to create a fairly complicated Trigger and I'm not sure if it can be done on phpMyAdmin.
Right now I have this query that creates a table with all the information I need from it.
CREATE TABLE SeniorDB_Shipping
SELECT
SeniorDB_Invoice.ID_Order,
SeniorDB_Customer.MCT_Code,
SeniorDB_Customer.Customer_Name,
SeniorDB_Customer.Customer_Address,
SeniorDB_Customer.Customer_City,
SeniorDB_Customer.Customer_State,
SeniorDB_Invoice.Shipping_Company
FROM SeniorDB_Customer
Join SeniorDB_Invoice ON SeniorDB_Customer.MCT_Code = SeniorDB_Invoice.MCT_Code
As you can see in the image, when I run the query, it pulls in information from the tables above the information. I'm trying (and failing) to create a trigger that will do this same thing without having to create a brand new table every single time. All the other posts I have seen are similar in regards to creating a table instead of inserting to a table.
What the trigger does is, when I enter the ID_Order, the rest of the information will get pulled from the database.
This is the trigger I have so far:
delimiter ~
create trigger SeniorDB_Shipping before insert on SeniorDB_Shipping
for each row begin
set new.SeniorDB_Shipping.MCT_Code = new.SeniorDB_Customer.MCT_Code,;
set new.SeniorDB_Shipping.Customer_Name = new.SeniorDB_Customer.Customer_Name,;
set new.SeniorDB_Shipping.Customer_Address = new.SeniorDB_Customer.Customer_Address,;
set new.SeniorDB_Shipping.Customer_City = new.SeniorDB_Customer.Customer_City,;
set new.SeniorDB_Shipping.Customer_State = new.SeniorDB_Customer.Customer_State,;
set new.SeniorDB_Shipping.Shipping_Company = new.SeniorDB_Customer.Shipping_Company,;
end~
delimiter ;
I feel like I'm right there. I just can't link it to when I enter the ID_Order.
This is the page if you would like to see the databases: http://polonium.forest.usf.edu/~sngamwon/SeniorProject/SeniorDB_Order.php
Ok, so you'll need to run this once:
/* Create the table with a primary key */
create table `SeniorDB_Shipping` (
`id` INT unsigned AUTO_INCREMENT NOT NULL,
primary key(id),
`ID_Order` int NOT NULL,
`MCT_Code` int NOT NULL,
`Customer_Name` varchar(255) NOT NULL,
`Customer_Address` varchar(255) NOT NULL,
`Customer_City` varchar(255) NOT NULL,
`Customer_State` varchar(255) NOT NULL,
`Shipping_Company` varchar(255) NOT NULL
) ENGINE=MyISAM CHARACTER SET=utf8 COLLATE utf8_general_ci;
Then you can run
/* Insert statement */
INSERT INTO `SeniorDB_Shipping` (
`ID_Order`,
`MCT_Code`,
`Customer_Name`,
`Customer_Address`,
`Customer_City`,
`Customer_State`,
`Shipping_Company`
) SELECT
invoice.ID_Order,
customer.MCT_Code,
customer.Customer_Name,
customer.Customer_Address,
customer.Customer_City,
customer.Customer_State,
invoice.Shipping_Company
FROM
SeniorDB_Customer as customer
Join SeniorDB_Invoice as invoice
ON customer.MCT_Code = invoice.MCT_Code;
I've run this in my own PHPMyAdmin, so it works. But I obviously don't have your schema. Known issues:
This will populate SeniorDB_Shipping with ALL the data from your two tables each time. Modify the query as required to select only recent data if that's not what you want. If ID_Order is a primary key you could check that doesn't already exist.
I've been doing a lot of new learning about MySQL and triggers. I think I understand the concept and I realise there are a LOT of possible dangers in using them. However I believe the limited use of them is correct for the function I want to perform.
I have 9 tables which correspond to 9 different web based Ajax engined forms. I've worked hard on these, being my first time using Ajax, and I'm reasonably happy with them. Each time a user makes a change to whichever form they are filling out, the change is Ajaxed back to the DB and they get a confirmation or error response. Fairly straight forward. Each forms respective table has a "status" field, a "lastModified" field and a field I call "agRef" which is sort of like status but is null until the form reaches a certain stage, further along the process.
I have an additional table called "records" which is where all entries in any of the other tables, is listed so we can easily see what forms have been started, when their last changes were made and what status's they have. So here is where I believe the trigger part should work, so that I don't have to make updates to the "records" table in my php on every single transaction.
The "records" table is set out like this:
`uaID` int(11) NOT NULL AUTO_INCREMENT,
`uID` int(11) NOT NULL,
`appNo` int(11) NOT NULL,
`applicationKey` varchar(8) NOT NULL,
`appID` int(11) DEFAULT NULL,
`applicationName` varchar(64) NOT NULL,
`agRef` varchar(32) DEFAULT NULL,
`status` varchar(32) NOT NULL,
`dateStarted` int(11) NOT NULL,
`lastModified` int(11) NOT NULL,
Now all of these fields are populated at the same time the matching entry is inserted into which ever one of the other 9 tables the form connects to. A small example of one of the other 9 tables would look like this:
`appID` int(11) NOT NULL AUTO_INCREMENT,
`uID` int(11) NOT NULL,
`uaID` int(11) NOT NULL,
`status` varchar(32) NOT NULL DEFAULT 'Data Acquisition',
`agRef` varchar(32) DEFAULT NULL,
`groupName` varchar(64) DEFAULT NULL,
`shortTitle` varchar(64) DEFAULT NULL,
`recipient` varchar(64) DEFAULT NULL,
`partOfValCh` varchar(64) DEFAULT NULL,
`sector` varchar(64) DEFAULT NULL,
`subSector` varchar(64) DEFAULT NULL,
`topic` varchar(64) DEFAULT NULL,
<snip because this can go on for a lot of lines>
`dateStarted` int(11) NOT NULL,
`lastModified` int(11) NOT NULL,
agRef on both tables remain null for now, appID is null on the records table initially at the point of creation but is updated immediately as soon as the corresponding entry is made into the second table, where it is generated by auto increment and then a call is made back to my records table to insert the appID there.
The three things that will change from any of the data tables are the three fields "status", "agRef", "lastModified".
So I'm trying to create a trigger that will do this after each alteration/update to the data table, so that the data in my records table is consistent and accurate.
This is my first ever trigger set up attempt:
DELIMITER $$
CREATE TRIGGER `dataTableOne_to_records_sync` AFTER UPDATE ON `dataTableOne`
FOR EACH ROW BEGIN
UPDATE records (agRef, status, lastModified) VALUES (NEW.agRef, NEW.status, NEW.lastModified) WHERE appID = OLD.appID;
END$$
DELIMITER ;
I am trying to set this up through phpmyadmin, but it is returning an error telling me I have a syntax problem within my UPDATE line. I feel that it is an issue with the WHERE part - the appID is the one common element that ties the row in "records" to the row being updated/changed in "dataTableOne". How do I set this up correctly? Is my error something more serious, and am I running the risk of creating a huge mess, like a never ending loop? I'm a bit paranoid about doing this for the first time. Thanks in advance for help and advice.
UPDATE I have now tried a few other trigger attempts but although MySQL will accept them as being valid trigger syntax, they always seem to break the entire DB functionality. Can anyone help me with my trigger syntax to get it to work correctly? In the demo tables above, if the SECOND table gets updated at all, I want the three fields copied over into the FIRST table by the trigger. The three values I want copied across are "status", "agRef", and "lastModified".
My most recent failed attempt was this:
CREATE TRIGGER AIGltInq_sync AFTER INSERT ON app_AIGltInq
FOR EACH ROW
UPDATE records r
SET r.agRef = NEW.agRef
, r.status = NEW.status
, r.lastModified = NEW.lastModified
WHERE uaID = NEW.uaID;
I'm not at all familiar with that form of the UPDATE statement.
To change values of columns in rows, we'd typically write an UPDATE statement like this:
UPDATE records r
SET r.agRef = NEW.agRef
, r.status = NEW.status
, r.lastModified = NEW.lastModified
WHERE r.appId = OLD.appID
Reference: https://dev.mysql.com/doc/refman/5.5/en/update.html
Question withdrawn. Triggers are seriously best to avoid, as they tend to cause more breakages than they fix! Most recommendations tend towards handling the function with whatever scripting language you are using to talk with the DB. In my case this is PHP and PHP is now performing all of the functionality I was hoping to short-cut by using triggers. Lesson? Don't take short-cuts when wanting to do the job right. :)
I've got a mysql database with a table (InnoDB) of Games:
gamerooms
id: bigint(20) unsigned not null auto_increment
PRIMARY KEY (`id`)
I'd like to start generating a UUID value for each row which I can share publicly, something like:
gamerooms
id | id_public |
--------------------
1 | abcde
2 | ghijk
3 | lmnop
...
select * from gamerooms where id_public = ...
How do I add this new column, also keeping in mind that there are already records in the table? I'm confused because the column should be marked NOT NULL, but after adding the column, all records that already exist would have empty values.. Do I have to provide a default value?:
ALTER TABLE `gamerooms` ADD COLUMN `id_public` varchar(36) DEFAULT something AFTER `id`
I want to put an index on id_public of course after it's created, so not sure if null values after the column is first created will mess anything up.
Also, I can use varchar(36) with mysqls UUID() output, right?
Thank you
Your ALTER statement is correct:
ALTER TABLE `gamerooms`
ADD COLUMN `id_public` varchar(36) NOT NULL DEFAULT 'something' AFTER `id`
According to my MySQL Pocket Reference, if you don't provide a default value for a column that is defined as NOT NULL:
MySQL picks a value based on the type of the field
In this case, I'm guessing the default would be empty string. Once your column has been added, simply create a new index for the column, and rebuild the index using a null alteration instruction like so:
CREATE INDEX myIndex ON gamerooms(id_public);
ALTER TABLE gamerooms ENGINE = InnoDB;
You may be able to create the index at the same time you do the insert. My MySQL-fu isn't strong enough to know how to do that.
Should the existing records have a value once you create this new column? If yes, you could do this in multiple steps. First, create the new column without constraint or index and then back populate it with the UUID for all existing records. Once everything is populated, add the not null constraint and your indexes.
As a UUID is a 128-bit number, you don't need a varchar column to store it. a char(16) column would just be ok for saving a UUID binary data.
ALTER TABLE `gamerooms` ADD COLUMN `id_public` char(16) NOT NULL DEFAULT '' AFTER `id`
I'm new to mysql triggers and I'm trying to figure it out how should a trigger be created for the following case.
I have a table with the following structure:
CREATE TABLE `trigger` (
`group` int(3) NOT NULL,
`order` int(3) NOT NULL,
`name` varchar(100) NOT NULL,
PRIMARY KEY (`group`,`order`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
This is how the table would look with some sample data:
The trigger that I want to create should make sure that, for each new record added with a given group, the order field is updated with the correct order index.
So, if I were to add a new record with the group 1, the order field will be automatically be updated to the next order which, for the given example would be 4.
The following statements inside a trigger should do the trick.
DECLARE neworder INTEGER;
SELECT max(`order`) + 1 INTO neworder FROM `trigger` WHERE `group` = NEW.`group`;
SET NEW.`order` = neworder;
BTW, it's not a great idea to use reserved words for table or column names.
You might want to reconsider your naming scheme.
I have a table "Bestelling" with 4 columns: "Id" (PK), "KlantId", "Datum", "BestellingsTypeId", now I want to make the column Id auto_increment, however, when I try to do that, I get this error:
ERROR 1062: ALTER TABLE causes auto_increment resequencing, resulting in duplicate entry '1' for key 'PRIMARY'
SQL Statement:
ALTER TABLE `aafest`.`aafest_bestelling` CHANGE COLUMN `Id` `Id` INT(11) NOT NULL AUTO_INCREMENT
ERROR: Error when running failback script. Details follow.
ERROR 1046: No database selected
SQL Statement:
CREATE TABLE `aafest_bestelling` (
`Id` int(11) NOT NULL,
`KlantId` int(11) DEFAULT NULL,
`Datum` date DEFAULT NULL,
`BestellingstypeId` int(11) DEFAULT NULL,
PRIMARY KEY (`Id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
Anyone got an idea?
This will happen if the table contains an existing record with an id of 0 (or negative). Updating all existing records to use positive values will allow auto_increment to be set on that column.
Edit: Some people asked how that 0 got in there. For clarification, the MySQL Reference Manual states that "For numeric types, the default is 0, with the exception that for integer or floating-point types declared with the AUTO_INCREMENT attribute, the default is the next value in the sequence." So, if you performed an insert on a table without providing a value for the numeric column before the auto_increment was enabled, then the default 0 would be used during the insert. More details may be found at https://dev.mysql.com/doc/refman/5.0/en/data-type-defaults.html.
I also had this issue when trying to convert a column to auto_increment where one row had a value of 0. An alternative to changing the 0 value temporarily is via setting:
SET SESSION sql_mode='NO_AUTO_VALUE_ON_ZERO';
for the session.
This allowed the column to be altered to auto_increment with the zero id in place.
The zero isn't ideal - and I also wouldn't recommend it being used in an auto_increment column. Unfortunately it's part of an inherited data set so I'm stuck with it for now.
Best to clear the setting (and any others) afterwards with:
SET SESSION sql_mode='';
although it will be cleared when the current client session clsoes.
Full details on the 'NO_AUTO_VALUE_ON_ZERO' setting here.
This happens when MySQL can not determine a proper auto_increment value. In your case, MySQL choose 1 as next auto_increment value, however there is already row with that value in the table.
One way to resolve the issue is to choose a proper auto_increment value yourself:
ALTER TABLE ... CHANGE COLUMN `Id` `Id` INT(11) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT = 123456;
(Note the AUTO_INCREMENT=123456 at the end.)
The easiest way that I have found to solve this issue is to first set the table's AUTO INCREMENT value before altering the column. Just make sure that you set the auto increment value higher than the largest value currently in that column:
ALTER TABLE `aafest`.`aafest_bestelling`
AUTO_INCREMENT = 100,
CHANGE COLUMN `Id` `Id` INT(11) NOT NULL AUTO_INCREMENT
I tested this on MySQL 5.7 and it worked great for me.
Edit: Don't know exactly how that would be caused, but I do have a workaround.
First, create a new table like the old one:
CREATE TABLE aafest_bestelling_new LIKE aafest_bestelling;
Then change the column
ALTER TABLE `aafest`.`aafest_bestelling_new`
CHANGE COLUMN `Id` `Id` INT(11) NOT NULL AUTO_INCREMENT
Dump in the new data:
INSERT INTO aafest_bestelling_new
(KlantId, Datum, BestellingTypeId)
SELECT
KlantId, Datum, BestellingTypeId
FROM aafest_bestelling;
Move the tables:
RENAME TABLE
aafest_bestelling TO aafest_bestelling_old,
aafest_bestelling_new TO aafest_bestelling;
Maybe there's some corruption going on, and this would fix that as well.
P.S.: As a dutchman, I'd highly recommend coding in english ;)
I had a similar issue. Issue was the table had a record with ID = 0 similar to what SystemParadox pointed out. I handled my issue by the following steps:
Steps:
Update record id 0 to be x where x = MAX(id)+1
Alter table to set primary key and auto increment setting
Set seed value to be x+1
Change record id x back to 0
Code Example:
UPDATE foo SET id = 100 WHERE id = 0;
ALTER TABLE foo MODIFY COLUMN id INT(11) NOT NULL AUTO_INCREMENT;
ALTER TABLE foo AUTO_INCREMENT = 101;
UPDATE foo SET id = 0 WHERE id = 100;
This happens because your primary key column already has values.
As the error says ...
ALTER TABLE causes auto_increment resequencing, resulting in duplicate entry '1' for key 'PRIMARY'
which means that your column already has a primary key value 1 which when you auto_increment that column is reassigned causing duplication and hence this error
the solution to this is to remove the primary constraint and then empty the column. Then alter the table setting the primary key again, this time with auto increment.
This error comes because the any table contains an existing record with an id of 0 (or negative). Update all existing records to use positive values will allow auto_increment to be set on that column.
If this didn't work then export all the data and save it any where in you computer and dont first make foreign key relation then fill data in parent table .
This error will also happen if have a MyISAM table that has a composite AUTO_INCREMENT PRIMARY KEY and are trying to combine the keys
For example
CREATE TABLE test1 (
`id` int(11) NOT NULL,
`ver` int(10) unsigned NOT NULL AUTO_INCREMENT,
PRIMARY KEY (`id`,`ver`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
INSERT INTO test1 (`id`, `ver`) VALUES (1,NULL),(1,NULL),(1,NULL), (2,NULL),(2,NULL),(2,NULL);
ALTER TABLE test1 DROP PRIMARY KEY, ADD PRIMARY KEY(`ver`);
Not being able to set an existing column to auto_increment also happens if the column you're trying to modify is included in a foreign key relation in another table (although it won't produce the error message referred to in the question).
(I'm adding this answer even though it doesn't relate to the specific error message in the body of the question because this is the first result that shows up on Google when searching for issues relating to not being able to set an existing MySQL column to auto_increment.)