Databases
StackOverflow2013
Postsdbo
POTriggers and multi-column Primary Keys
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POTriggers and multi-column Primary Keys
    primarykey
    data
    text
    <p>I have a books table and a music table. Both of these tables have a Product_ID as their primary key. I also have a products table that has a Product_ID column and a type column (0 for books, 1 for music) where the Product_Id and Type columns are the primary key for the table. In phpMyAdmin, these 2 columns are underlined and SHOW COLUMNS for the table shows Type and Product_Id marked as primary keys.</p> <p>The problem I'm having is with my trigger. There are 2 triggers, with a couple of differences to handle the different tables. The music trigger for example executes this statement:</p> <pre><code> INSERT INTO products SET Type=1, Product_Id=NEW.Product_ID, Title=NEW.Album, Price=0 </code></pre> <p>The books trigger is the same, except type=0 and NEW.Album is replaced with NEW.Title. When I'm running an INSERT query now though, after some data has been inserted and deleted, I'm getting a duplicate primary key error. The problem is that the MySQL database is only reading the Product_ID column as a primary key, so when its trying to insert a duplicate there, it spits out this error even though it the value in the Type column is different. I'm stumped here.</p> <p>The products table</p> <pre><code>Product_Id int(11) - PK Title int(11) Price double Type int(11) - PK NewBool tinyint(1) </code></pre> <p>The music Table</p> <pre><code>Product_ID int(11) - PK Artist varchar(32) Album varchar(32) Genre varchar(32) Year int(11) Length double Rating double NumRatings int(11) Studio varchar(64) </code></pre> <p>The books table</p> <pre><code>Product_ID int(11) - PK ISBN bigint(20) Title text Author text Year int(11) Genre text Pages int(11) Publisher text Edition int(11) Rating double NumRatings int(11) </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USgdawgrancid
    1. USgdawgrancid
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COPlease post your tables definitions. I dont think MySQL will ignore a primary key definition otherwise there would be a lot more complaints like this.
      singulars
      1. POTriggers and multi-column Primary Keys
      1. USNamphibian
    2. COI added the tables in question in my post. Checking from the MySQL Console and in phpMyAdmin, the products table shows that Type and Product_ID are the primary key for that table.
      singulars
      1. POTriggers and multi-column Primary Keys
      1. USgdawgrancid
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload