July 2007 - postmodern-devel - mailman3.common-lisp.net

[postmodern-devel] postmodern, pg, cl-rdbms
by Attila Lendvai 27 Aug '07

27 Aug '07

hello list, i've recently found postmodern on cl.net, and i was wondering that there seems to be a massive amount of duplication of efforts among the following projects: - pg is a long-time postgresql socket based lib: http://common-lisp.net/project/pg/ - cl-rdbms (our fresh clsql replacement, http://common-lisp.net/project/cl-rdbms/ ) which aims to be a backend independent sql lib, just like clsql, with sexp sql syntax ( see http://common-lisp.net/cgi-bin/darcsweb/darcsweb.cgi?r=cl-rdbms-cl-rdbms;a=… for a quick impression ). it has a single backend for now, based on pg. - and postmodern which is something like a mixture of pg and cl-rdbms we should bring out the best of these... my first impression of postmodern is that it's more modern and better organized code then pg which is good. and to also write actual suggestions besides to this rant, i'd use http://common-lisp.net/project/local-time/ as the date/time abstraction data type. it supports timezones and has a string parser/printer. and fyi, trivial-sockets seems to be a dead project. i've tried to contact the author several times with patches and there wasn't any response; #lisp is on the same opinion. usocket at least welcomes patches, but it's not really important if t-s can already do everything needed. any toughts? -- - attila "- The truth is that I've been too considerate, and so became unintentionally cruel... - I understand. - No, you don't understand! We don't speak the same language!" (Ingmar Bergman - Smultronstället)

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[postmodern-devel] Can't nest QUERY within prepared-statement QUERY
by J.P. Larocque 30 Jul '07

30 Jul '07

Hi again, Thanks for the fix and the new release, Marijn. I think I found another problem. When I try to query with a prepared statement with the QUERY macro, and one of the arguments to the statement is the result of another QUERY macro (whether directly or from the result of a function), strange things crop up. In one instance, the inner QUERY was returning nil where it would return the expected integer otherwise. Here's an isolated case: (postmodern:query "select cast ($1 as int)" (let ((foo (postmodern:query "select 12" :single))) (format t "result: ~S~%" foo) foo)) This gives me the expected message "result: 12", but also signals a condition, "Database error: Incorrect number of parameters given for prepared statement ." Below is the complete macroexpansion of the above form (without LET and FORMAT). (PROGN (CL-POSTGRES:PREPARE-QUERY POSTMODERN:*DATABASE* "" "select cast ($1 as int)") (CL-POSTGRES:EXEC-PREPARED POSTMODERN:*DATABASE* "" (MAPCAR 'S-SQL:SQL-IZE (LIST (CAR (CL-POSTGRES:EXEC-QUERY POSTMODERN:*DATABASE* "select 12" 'POSTMODERN::COLUMN-ROW-READER)))) 'CL-POSTGRES:LIST-ROW-READER)) The sequence of evaluation is PREPARE-QUERY, then EXEC-QUERY (for the inner "select 12"), then EXEC-PREPARED. I guessed that doing things with the database in-between PREPARE-QUERY and EXEC-PREPARED might be the problem, so I modified QUERY to evaluate prepared-statement arguments before PREPARE-QUERY. This allows the inner query to complete before the outer one actually starts. diff -urNx '*~' postmodern-1.02/postmodern/query.lisp postmodern-1.02-modified/postmodern/query.lisp --- postmodern-1.02/postmodern/query.lisp 2007-07-25 04:10:42.000000000 -0700 +++ postmodern-1.02-modified/postmodern/query.lisp 2007-07-27 23:03:16.000000000 -0700 @@ -55,9 +55,10 @@ :else :collect arg))) (destructuring-bind (reader single-row) (cdr (assoc format *result-styles*)) (let ((base (if args - `(progn - (prepare-query *database* "" ,(real-query query)) - (exec-prepared *database* "" (mapcar 'sql-ize (list ,@args)) ',reader)) + (let ((arg-values (gensym))) + `(let ((,arg-values (mapcar 'sql-ize (list ,@args)))) + (prepare-query *database* "" ,(real-query query)) + (exec-prepared *database* "" ,arg-values ',reader))) `(exec-query *database* ,(real-query query) ',reader)))) (if single-row `(multiple-value-call 'car-of-first-value ,base) Now my first example works, as does the result of one prepared-statement QUERY's being indirectly nested in another prepared-statement QUERY. -- J.P. Larocque: <piranha(a)thoughtcrime.us>, <piranha(a)ely.ath.cx>

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[postmodern-devel] Mainainer absence
by Marijn Haverbeke 28 Jul '07

28 Jul '07

Hello Postmodern-users, Starting somewhere at the end of next week, I will be travelling. How long this is going to take is not clear yet, but it will mean that I will be less actively maintaining the library. I will read my e-mail now and then, and applying a patch sent to me should be possible whenever I come across an internet cafe that lets me use SSH, but I certainly won't be writing any patches or properly testing things sent to me. If anyone feels up to it, I wouldn't mind giving someone else commit rights to the repository. (I will, of course, still be hanging over your shoulder trying to enforce my extremist ideas about clean interfaces and up-to-date documentation.) Another option is that somebody sets up a 'secondary' repository, advertises it on this list, and keeps it up to date with whatever bug-fixes and features people come up with. Cheers, Marijn

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[postmodern-devel] bug in query (or deeper)
by Ryszard Szopa 28 Jul '07

28 Jul '07

If you do something like this: > (postmodern::query '(:select 1)) The value (:SELECT 1) is not of type STRING. [Condition of type TYPE-ERROR] Restarts: 0: [ABORT] Return to SLIME's top level. 1: [TERMINATE-THREAD] Terminate this thread (#<THREAD "repl-thread" {AF37921}>) 0 the slime-repl buffer starts waiting for something (probably some response from the database). When you hit C-c, and select abort, it stops. Afterwards, however, the database connection is lost: > (postmodern::query (:select 1)) Database error: Connection to database server lost. [Condition of type DATABASE-CONNECTION-LOST] Restarts: 0: [RECONNECT] Try to reconnect. 1: [ABORT] Return to SLIME's top level. 2: [TERMINATE-THREAD] Terminate this thread (#<THREAD "repl-thread" {AF37921}>) The problem lies probably somewhere deeper than in query. If I have some time, I'll try to investigate it. Cheers, -- Richard -- http://szopa.tasak.gda.pl/

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[postmodern-devel] Can't prepare query with :NULL
by J.P. Larocque 25 Jul '07

25 Jul '07

Hi, I can't use the value :NULL in a Postmodern prepared query: > (postmodern:query "select cast ($1 as int)" :null :single) debugger invoked on a CL-POSTGRES:DATABASE-ERROR in thread #<THREAD "initial thread" {10025599C1}>: Database error 08P01: bind message supplies 0 parameters, but prepared statement "" requires 1 Query: select cast ($1 as int) (The cast was given so that the type of the expected value would be known.) If I understand PostgreSQL and Postmodern correctly, this should return the Lisp value NIL. I have no similar problem with SQL and SQL-COMPILE, since these apparently don't technically do query preparation. I believe there is an error in the QUERY macro which is causing this. The loop which determines ARGS sees :NULL as a keyword symbol and assumes this means it is an output format. Instead of checking each member of ARGS/FORMAT to see if it is a keyword symbol, I would check for its membership in a list of possible valid format symbols. Alternatively, I'd take the idea of the DB-NULL type to an extreme, writing Lisp type definitions for each supported SQL type, and also write a type (e.g. DB-VALUE) that is the OR of all of these types. (It looks something similar was already done.) In the QUERY macro, only if an argument isn't of the type DB-VALUE would it be considered an output format. -- J.P. Larocque: <piranha(a)thoughtcrime.us>, <piranha(a)ely.ath.cx>

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