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

[postmodern-devel] with-connection problem
by Jens Teich 18 Sep '07

18 Sep '07

What's wrong here? Tested with LW and SBCL. Thanks Jens POMO> (with-connection ("web_access" "web_access" "***" "localhost") (query (:select '* :from 'dokumente-files))) (("s5s732006l9t5i0ai3a308281gwdh5 " "z_z15p02" "Bilddata/AZ/Pdf/Az15_16/baumuste" "pdf" 1914355) ...... POMO> (defparameter *db* '("web_access" "web_access" "***" "localhost")) *DB* POMO> (with-connection *db* (query (:select '* :from 'dokumente-files))) error while parsing arguments to DEFMACRO WITH-CONNECTION: bogus sublist *DB* to satisfy lambda-list (DATABASE USER PASSWORD HOST &KEY (PORT 5432) POOLED-P) [Condition of type SB-KERNEL::DEFMACRO-BOGUS-SUBLIST-ERROR]

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[postmodern-devel] query with keyword :on
by Jens Teich 17 Sep '07

17 Sep '07

This is an example from the documentation which gives strange results on Lispworks 5.0.2. I'm using the latest version of postmodern (1.02) CL-USER 3 > (postmodern:sql (:select (:+ 'field-1 100) 'field-5 :from (:as 'my-table 'x) :left-join 'your-table :on (:= 'x.field-2 'your-table.field-1) :where (:not-null 'a.field-3))) "(SELECT (field_1 + 100), field_5 FROM my_table AS x LEFT JOIN your_table ON (x.field_2 = your_table.field_1), your_table, on, (x.field_2 = ................................^ your_table.field_1) WHERE not_null(a.field_3))" Jens PS my previous problem with if statement is solved, I needed a macro instead of a function

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[postmodern-devel] Submarine announcement
by Ryszard Szopa 04 Sep '07

04 Sep '07

Hello Marijn and Postmodern users, I was a bit dissatisfied with Postmodern's DAO system and lack of support for foreign keys. At first, I wrote just a patch that added support for foreign keys, but it turned the macro DEFTABLE into something that had more than 100 lines and was pretty unmaintainable. So, I left Postmodern's sources alone and wrote a library over it, something between Postmodern and an object persistency library. I've used it in some of my projects at work, and now I decided to make it open source. In a couple of days I'll start it a common-lisp.net project and announce it to c.l.l. In the meantime, I will be very grateful for any comments. I encourage you to at least take a look at the example file: http://bender.streamtech.nl/darcs/submarine/doc/example.lisp Here are the contents of my README file: Submarine is a Common Lisp library that's somewhere between a PostgreSQL library an an object persistency system. It uses Postmodern to communicate with the database. The basic idea is that you create your classes in the metaclass DB-CLASS and submarine cares about creating SQL tables or, if the tables already exist, checking if they conform to the provided specification. Moreover, Submarine supports an intuitive way of expressing both one-to-many and many-to-many relations. Getting submarine ================= At the moment there's only a darcs repository available: darcs pull http://bender.streamtech.nl/darcs/submarine/ You will also need my mop-utilities, which may be incorporated into submarine in the close future: darcs get http://bender.streamtech.nl/darcs/mop-utils Dependencies ============ Submarine depends on Postmodern and Iterate. It uses also my library of MOP utilities, MOP-UTILS, which may become a separate library in the future. On platforms other than SBCL, mop-utils needs Closer-mop. License ======= Submarine is released under a BSD-like license. Which approximately means you can use the code in whatever way you like, except for passing it off as your own or releasing a modified version without indication that it is not the original. Relation to Postmodern ====================== Submarine started as a patch that added, among others, foreign keys support to Postmodern. This meant hacking the DEFTABLE macro and TABLE and TABLEFIELD classes. After some time I realized that my modified Postmodern macros had become far too large and heavy to be easy maintainable. So, I decided to leave Postmodern's code as it was and write a separate library. Introduction for Postmodern users ================================= Submarine tries to keep as much as possible of Postmodern's original API. I use the same terminology, and functions with similar names will probably do very similar things. My purpose was twofold. First of all, I wanted to make porting programs using Postmodern to Submarine easy. Secondly, this would allow me to use some of Marijn Haverbeke's superb documentation nearly without any changes. Main differences between Postmodern and Submarine: * You don't have to create DAO (database access object) classes and SQL tables separately. You just create classes belonging to a certain metaclass, and the library cares of the rest. * If the table with an appropriate name exists in the database, Submarine will test if it has columns with the right names and types. If a column does not exist or has a wrong type, Submarine will offer the user a possibility to fix it. Submarine will warn, but do nothing about any additional columns in the table. * Each DB-CLASS class has its own connection specification. This means that you can just access your objects, without wrapping them in a WITH-CONNECTION macro, and they will care about setting the right connection. * DAO is a basis class for DB-CLASS classes, and methods that are supposed to work on an object of any DB-CLASS class use DAO as a dispatch type. Of course, you don't have to use DAO as a base class, but it makes a lot of things easier. * Submarine supports foreign keys. If you define a DB-CLASS class with a slot whose type is another DB-CLASS, it is treated as foreign key and an appropriate constraint is added to the database. * Submarine provides a function to retrieve all the elements of a given type standing in a many-to-one relation with some DAO object. * The DEF-MANY-TO-MANY macro defines a many-to-many relation between two classes and creates methods appropriate to their retrieval (it creates a link table in the database). * DB-CLASS slots have an additional attribute TRANSIENT. If you set it to a non-NIL value, it will behave just as a STANDARD-SLOT-DEFINITION and will be ignored in database related operations. * Submarine uses MOP rather than macros to achieve its purposes. This makes it easier to maintain and to extend. At the moment there's no real documentation apart from docstrings, but there's a poor man's tutorial in the file http://bender.streamtech.nl/darcs/submarine/doc/example.lisp (this should give you a pretty good overview of the possibilities of Submarine. Bests, -- Richard -- http://szopa.tasak.gda.pl/

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[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] conditional query building
by Jens Teich 16 Aug '07

16 Aug '07

> (postmodern:sql (:= 's 'tr)) => "(s = tr)" > (postmodern:sql (if t (:= 's 'tr))) => Error: Undefined operator := in form (:= (QUOTE S) (QUOTE TR)). How do I make this work? I want to build more complex where clauses using cl:if. Jens

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[postmodern-devel] Join Slots
by Jens Teich 13 Aug '07

13 Aug '07

I'm considering to change from clsql to postmodern because I need unicode support. In clsql the following viewclass definition is possible with join slots: (clsql:def-view-class elements () ((guid :reader element-guid :db-kind :key :type (string 36)) (lang_id :db-kind :key :type (string 2)) ... more ... 'normal' slots) (produkt :reader product-element :db-kind :join :db-info (:join-class produkte :home-key (guid_objekt lang_id) :foreign-key (guid lang_id) :set nil))) (:base-table project-elements)) so that I can access the joined records easily via (product-element instance-of-element) How do I do this with postmodern? Thanks Jens

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