How to do basic CRUD apps with Python

[g_teodorescu at yahoo.com]

walterbyrd a scris:
> With PHP, libraries, apps, etc. to do basic CRUD are everywhere. Ajax
> and non-Ajax solutions abound.
>
> With Python, finding such library, or apps. seems to be much more
> difficult to find.
>
> I thought django might be a good way, but I can not seem to get an
> answer on that board.
>
> I would like to put together a CRUD grid with editable/deletable/
> addable fields, click on the headers to sort. Something that would
> sort-of looks like an online  spreadsheet. It would be nice if the
> fields could be edited in-line, but it's not entirely necessary.
>
> Are there any Python libraries to do that sort of thing? Can it be
> done with django or cherrypy?
>
> Please, don't advertise your PHP/Ajax apps.

SqlAlchemy - SqlSoup - PyQt4 (fragment) example:

import sys
from PyQt4.Qt import *
from PyQt4 import uic
from avc.avcqt4 import *
from sqlalchemy.ext.sqlsoup import SqlSoup

from ui_db import Ui_DbForm

class DbForm(QWidget,AVC):
    def __init__(self, parent=None):
        QWidget.__init__(self,parent)

        self.ui = Ui_DbForm()
        self.ui.setupUi(self)

        # current index
        self.crtIndex = 0
        self.crtPk = 0

        # avc variables, same names as form widgets (lineEdit, combo,
etc....)
        self.edtId = 0
        self.edtFirstName = ""
        self.edtLastName = ""
        self.edtSalary = 0.0

        self.connect(self.ui.btnQuit, SIGNAL("clicked()"),
                     qApp, SLOT("quit()"))

        self.connect(self.ui.btnFirst, SIGNAL("clicked()"),
self.goFirst)
        self.connect(self.ui.btnPrior, SIGNAL("clicked()"),
self.goPrior)
        self.connect(self.ui.btnNext, SIGNAL("clicked()"),
self.goNext)
        self.connect(self.ui.btnLast, SIGNAL("clicked()"),
self.goLast)

        self.connect(self.ui.btnSave, SIGNAL("clicked()"),
self.doSave)
        self.connect(self.ui.btnAdd, SIGNAL("clicked()"), self.doAdd)
        self.connect(self.ui.btnDel, SIGNAL("clicked()"),
self.doDel)

        # connection: 'postgres://user:password@address:port/db_name'
        self.db = SqlSoup('postgres://postgres:postgres@localhost:5432/
testdb')

        self.goFirst()



    def goFirst(self):
        self.crtIndex = 0
        self.doRead(self.crtIndex)

    def goPrior(self):
        if self.crtIndex > 0:
            self.crtIndex = self.crtIndex - 1
        else:
            self.crtIndex = 0
        self.doRead(self.crtIndex)

    def goNext(self):
        maxIndex = self.db.person.count() - 1
        if self.crtIndex < maxIndex:
            self.crtIndex = self.crtIndex + 1
        else:
            self.crtIndex = maxIndex
        self.doRead(self.crtIndex)

    def goLast(self):
        maxIndex = self.db.person.count() - 1
        self.crtIndex = maxIndex
        self.doRead(self.crtIndex)

    def doSave(self):
        if self.crtPk == 0:
            # aflu pk-ul si adaug o inregistrare goala
            newPk = self.db.engine.execute("select
nextval('person_id_seq')").fetchone()[0]
            self.crtPk = newPk
            self.db.person.insert(id=self.crtPk, firstname='',
lastname='', salary=0.0)
            self.db.flush()
        person = self.db.person.selectone_by(id=self.crtPk)
        person.firstname = self.edtFirstName
        person.lastname = self.edtLastName
        person.salary = self.edtSalary
        self.db.flush()

    def doAdd(self):
        self.crtPk = 0
        self.edtId = self.crtPk
        self.edtFirstName = ""
        self.edtLastName = ""
        self.edtSalary = 0.0
        # inregistrarea trebuie salvata explicit
        # prin apasarea butonului "Save"

    def doDel(self):
        mk = self.db.person.selectone_by(id=self.crtPk)
        self.db.delete(mk)
        self.db.flush()
        self.goNext()

    def doRead(self, index):
        person = self.db.person.select()
        self.edtId = person[index].id
        self.edtFirstName = person[index].firstname
        self.edtLastName = person[index].lastname
        self.edtSalary  = person[index].salary
        # invariant pt. toate operatiile, mai putin adaugare
inregistrare
        # pk-ul nu se poate modifica prin edtId !!!
        self.crtPk = person[index].id


if __name__ == "__main__":
    app = QApplication(sys.argv)
    # QApplication.setStyle(QStyleFactory.create("Cleanlooks"))
    QApplication.setStyle(QStyleFactory.create("Plastique"))
    form = DbForm()
    form.avc_init()
    form.show()
    sys.exit(app.exec_())