[SOLVED] lost categories

[jakebur01]

hey, I was doing an update and accidentally gave all my products categories a 0 value.

 

So I want to take the category code "catid" from my old table and update it into my new table where it matches the product number.

 

How could I do this?

[Wildbug]

If you have both tables loaded within the same instance of MySQL, you can:

 

USE new_db;
UPDATE products AS new JOIN old_db.products AS old ON new.category=old.category SET new.catid=old.catid;

 

That should work.  You may want to make sure it's backed up, though.

[jakebur01]

what if they are in the same database and I just have the tables named differently? The table I screwed up is "books" and the backup table is "item". I deleted all the columns from "item" except the "isbn" column and the "catid" column. Which is the part number and category code.

 

I am wanting to take the catid from table "item" and put it in table "books" where the "isbn" matches up.

[Wildbug]

Same idea.  Just easier.

 

UPDATE books,item SET books.catid=item.catid WHERE books.isbn=item.isbn;