Very basic DB problems

[vintermann]

I'm trying to do some very basic things with databases, just running the code from the manual, but I run into trouble:

I do this:

Code: [show] | [select all] lua

        db:create("people", {friends={"name", "city", "notes"}, enemies={"name", "city", "notes"}})

then this:

Code: [show] | [select all] lua

mydb = db:get_database("people")

then this:

Code: [show] | [select all] lua

        db:add(mydb.friends, {name="Ixokai", city="Magnagora"})

Then I get this in the errors log: </usr/share/games/mudlet/lua/DB.lua:627: Failed to add item: this is probably a violation of a UNIQUE index or other constraint.>

What's this? I'm on 64-bit Ubuntu, using the package mudlet_2.0-rc11-1ubuntu7_amd64.deb which I found a link to on this forum (I tried to install from the PPA, but what was there had issues such as segfaulting on all aliases.)

[Vadi]

Someone else ran into this, I showed them a solution that worked... should be somewhere on forums here.

[vintermann]

I did search the forums before posting, and I can't find it - or, at least not anything that appears to work for me. I tried declaring the schema with default initializers, but that didn't help.

Sure this isn't a regression, or something specific to this build?

I will try building from git tomorrow, to see what I can find of more information, but it's a lot of pain for getting code direct from the manual to work.

[Jinresh]

I am new to mudlet and I was working through the manual as well, trying to learn how to use the databases in mudlet, and I have run into the same problem.

LUA: ERROR running script ^mudlettest (Alias130) ERROR:./mudlet-lua/lua/DB.lua:627: Failed to add
item: this is probably a violation of a UNIQUE index or other constraint.

I did search the forums and saw that Vadi posted about using db:merge_unique() in place of the db:add() function. Unfortunately this solution hasn't worked for me either. I receive a different error,

LUA: ERROR running script ^mudlettest (Alias130) ERROR:./mudlet-lua/lua/DB.lua:922: db:merge_unique
only works on a sheet with a unique index.

I looked at the database file using SQLite Sorcerer and the sheet in the database doesn't seem to have any fields aside from the standard "_rowid". I've tried different ways of initializing the database creation but I can't get it to actually create any fields (which is likely why db:add() and db:merge_unique() are not working).

So I am not quite sure how to go about actually using the databases in mudlet at this point. I am following the basic steps from the manual, posted at the beginning of this thread, and can't seem to get anything working regarding databases.

Any help would be greatly appreciated!

[Lucky24]

I had issues with MERGE_UNIQUE simply not working. I ended up serializing my tables with table.load() and table.save(), instead of using the db stuff.

Also, check out the tsujin's generic luasql front-end, which you can use if you're familiar with SQL http://forums.mudlet.org/viewtopic.php? ... lit=luasql

[Vadi]

db: has been fixed and in a future Mudlet update, the example will work as expected.