Re: TR: Manipulating "categories" in a php database

Tim wrote:

Hello all, This is more of a conceptional question rather then a technical one. I am developping an online catalog, the catalog is a standard categorie/subcat/subsubcat system using the following logic in my database: What type of DB?

cat_id cat_name

10        DVD

1010     DVD/Action

1020     DVD/Adventure

20        CD

2010     CD/Reggae

2020     CD/Electro

Up to now I enter the category id's manually from an administration console. ouch...

I would like to be able to have my console automagically generate a cat_id in mysql use auto_increment on the column and set it to PRIMARY KEY

This will create a unique index for each row that is inserted to the table.

when my users add categories (so they don't have to bother with that aspect of adding a category) and I would also like to be able to move a category up or down in the way it displays on the page, as of now I am sorting by cat_id create a master_cat_id column and set that to the parent category for a given category, and then if the master_cat_id is not set, then you know that it is a top level/parent of a category.

I have been for a while trying to develop a logical scheme to be able to generate the id's and change their cat_id to reflect a "new" position in how it displays (displaying DVD/Action after DVD/Adventure for example I would need to change the cat_id from 1010 to something above 1020 say 1021). This is fine as I can test the previous elements cat_id and add or subtract 1 but I get stuck when I have a cat_id say 1010 that I would want to put between 1011 and 1012. I'm having trouble developing the algorithm that would allow this.. How are you wanting the categories to be displayed? in a specific order or alphabetically?

If you are wanting a specific order, you will have to create a new column for display order, then build a sorting feature into your app that would allow you to increase or decrease the display order

Would appreciate any "ideas" that may help me conclude this function in my module. Regards, Tim Earl

-- Enjoy, Jim Lucas Different eyes see different things. Different hearts beat on different strings. But there are times for you and me when all such things agree. - Rush