Virtual columns in MariaDB

ansgar's profile image ansgar posted 13 years ago in News Permalink
Virtual and persistent columns are a feature of MariaDB 5.2+, and HeidiSQL's table editor now fully supports them. Just update your HeidiSQL to the latest build to see this in action.

Also, if you are on a MariaDB server, a brown seal icon in the tree and in the status bar now indicates the right server vendor:
2 attachment(s):
  • virtual-columns
  • mariadb-icon
fbachofner's profile image fbachofner posted 10 years ago Permalink
I am trying to create and expression which will calculate the difference between two columns in a virtual field.

Similar to your table structure above, it would seem the expression for column "c" would be b-a (assuming all columns a, b and c are integers, for example - with appropriate sizes - i.e. c is big enough to hold b-a).

I keep getting the error "1907: this is not yet supported for computed columns"

I am running MariaDB v. 5.5.35

Any help would be appreciated!

[Today I am wearing a HeidiSQL t-shirt I received at MySQL Conference (approximately 2009 or 2010) in the hopes I would be inspired to have fewer coding problems. Look where it got me! wink ]

ansgar's profile image ansgar posted 10 years ago Permalink
Guess you have the shirt from the jHeidi developer Bill, who was at the conference at that time. See here for some photos:

I found a hint saying that virtual columns cannot be modified:
fbachofner's profile image fbachofner posted 10 years ago Permalink
Hi Ansgar:

D'Oh! I saw the same "no alter" rule in the main MariaDB KnowledgeBase for virtual columns

Unfortunately, I somehow understood that to mean "no alter once the virtual column is established" [I was trying to modify a "regular" column (which, further, had never contained any data) into a virtual one which in my opinion meant I was not modifying the virtual column . . . Grrrrr. I hate when I fail to look at an instruction from more than one angle.]

OK, I dropped my original column, made a new one as virtual AT THE TIME OF COLUMN CREATION . . . and it works!


Yep, this is the shirt I had on today.

HeidiSQL already showed great promise at that 2009 conference, but I was already a licensee of SQLYog and used that for most of my MySQL db work.

Just 5 years later (I started using HeidiSQL fairly seriously about 8 months ago), your tool is better than ANY competitor's, particularly in terms of usability and intuitiveness. The only reason I still keep SQLYog around is for automation and synchronisation (data, schema, etc). The automation and synchronization can also work together in SQLYog, a killer feature! I mentioned it previously here.

Please login to leave a reply, or register at first.