[Haskell-cafe] Re: Could someone give me a sample about haskelldb?
gue.schmidt at web.de
Fri Jun 19 07:33:12 EDT 2009
restrict (t!T.done .<>. constant False) should dot it
but your t!T.done confuses me, is the the T.xxx due to an import?
also the line 49 does not seem to be right. Would you mind to post your
table and column definitions?
Magicloud Magiclouds schrieb:
> I changed it, some other problem occured.
> 1. How to compare a BoolT column to a True? "t!c .<>. True" could not work.
> 2. What shoud I use after "!"? Like table!col, recordset!col, what is col?
> On Fri, Jun 19, 2009 at 1:24 PM, Magicloud
> Magiclouds<magicloud.magiclouds at gmail.com> wrote:
>> I am learning it following the very few documents on its site. Well,
>> I failed, with the import modules, I still cannot compile it. The
>> error is on "T.*".
>> 6 import Database.HaskellDB.HDBC.SQLite3
>> 7 import Database.HaskellDB
>> 8 import Database.HaskellDB.DBSpec
>> 9 import Database.HaskellDB.DBSpec.PPHelpers
>> 10 import Database.HaskellDB.Query
>> 48 q = do
>> 49 t <- table $ Table "notes" 
>> 50 restrict ( t!T.done .<>. False )
>> 51 r <- project ( T.subject << t!T.subject )
>> 52 order [ desc r T.priority
>> 53 , desc r T.dt ]
>> 54 return r
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