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  • Python - help on custom wx.Python (pyDev) class

    - by Wallter
    I have been hitting a dead end with this program. I am trying to build a class that will let me control the BIP's of a button when it is in use. so far this is what i have (see following.) It keeps running this weird error TypeError: 'module' object is not callable - I, coming from C++ and C# (for some reason the #include... is so much easier) , have no idea what that means, Google is of no help so... I know I need some real help with sintax and such - anything woudl be helpful. Note: The base code found here was used to create a skeleton for this 'custom button class' Custom Button import wx from wxPython.wx import * class Custom_Button(wx.PyControl): # The BMP's # AM I DOING THIS RIGHT? - I am trying to get empty 'global' # variables within the class Mouse_over_bmp = None #wxEmptyBitmap(1,1,1) # When the mouse is over Norm_bmp = None #wxEmptyBitmap(1,1,1) # The normal BMP Push_bmp = None #wxEmptyBitmap(1,1,1) # The down BMP Pos_bmp = wx.Point(0,0) # The posisition of the button def __init__(self, parent, NORM_BMP, PUSH_BMP, MOUSE_OVER_BMP, pos, size, text="", id=-1, **kwargs): wx.PyControl.__init__(self,parent, id, **kwargs) # The conversions, hereafter, were to solve another but. I don't know if it is # necessary to do this since the source being given to the class (in this case) # is a BMP - is there a better way to prevent an error that i have not # stumbled accost? # Set the BMP's to the ones given in the constructor self.Mouse_over_bmp = wx.Bitmap(wx.Image(MOUSE_OVER_BMP, wx.BITMAP_TYPE_ANY).ConvertToBitmap()) self.Norm_bmp = wx.Bitmap(wx.Image(NORM_BMP, wx.BITMAP_TYPE_ANY).ConvertToBitmap()) self.Push_bmp = wx.Bitmap(wx.Image(PUSH_BMP, wx.BITMAP_TYPE_ANY).ConvertToBitmap()) self.Pos_bmp = self.pos self.Bind(wx.EVT_LEFT_DOWN, self._onMouseDown) self.Bind(wx.EVT_LEFT_UP, self._onMouseUp) self.Bind(wx.EVT_LEAVE_WINDOW, self._onMouseLeave) self.Bind(wx.EVT_ENTER_WINDOW, self._onMouseEnter) self.Bind(wx.EVT_ERASE_BACKGROUND,self._onEraseBackground) self.Bind(wx.EVT_PAINT,self._onPaint) self._mouseIn = self._mouseDown = False def _onMouseEnter(self, event): self._mouseIn = True def _onMouseLeave(self, event): self._mouseIn = False def _onMouseDown(self, event): self._mouseDown = True def _onMouseUp(self, event): self._mouseDown = False self.sendButtonEvent() def sendButtonEvent(self): event = wx.CommandEvent(wx.wxEVT_COMMAND_BUTTON_CLICKED, self.GetId()) event.SetInt(0) event.SetEventObject(self) self.GetEventHandler().ProcessEvent(event) def _onEraseBackground(self,event): # reduce flicker pass def _onPaint(self, event): dc = wx.BufferedPaintDC(self) dc.SetFont(self.GetFont()) dc.SetBackground(wx.Brush(self.GetBackgroundColour())) dc.Clear() dc.DrawBitmap(self.Norm_bmp) # draw whatever you want to draw # draw glossy bitmaps e.g. dc.DrawBitmap if self._mouseIn: # If the Mouse is over the button dc.DrawBitmap(self, self.Mouse_over_bmp, self.Pos_bmp, useMask=False) if self._mouseDown: # If the Mouse clicks the button dc.DrawBitmap(self, self.Push_bmp, self.Pos_bmp, useMask=False) Main.py import wx import Custom_Button from wxPython.wx import * ID_ABOUT = 101 ID_EXIT = 102 class MyFrame(wx.Frame): def __init__(self, parent, ID, title): wxFrame.__init__(self, parent, ID, title, wxDefaultPosition, wxSize(400, 400)) self.CreateStatusBar() self.SetStatusText("Program testing custom button overlays") menu = wxMenu() menu.Append(ID_ABOUT, "&About", "More information about this program") menu.AppendSeparator() menu.Append(ID_EXIT, "E&xit", "Terminate the program") menuBar = wxMenuBar() menuBar.Append(menu, "&File"); self.SetMenuBar(menuBar) self.Button1 = Custom_Button(self, parent, -1, "D:/Documents/Python/Normal.bmp", "D:/Documents/Python/Clicked.bmp", "D:/Documents/Python/Over.bmp", wx.Point(200,200), wx.Size(300,100)) EVT_MENU(self, ID_ABOUT, self.OnAbout) EVT_MENU(self, ID_EXIT, self.TimeToQuit) def OnAbout(self, event): dlg = wxMessageDialog(self, "Testing the functions of custom " "buttons using pyDev and wxPython", "About", wxOK | wxICON_INFORMATION) dlg.ShowModal() dlg.Destroy() def TimeToQuit(self, event): self.Close(true) class MyApp(wx.App): def OnInit(self): frame = MyFrame(NULL, -1, "wxPython | Buttons") frame.Show(true) self.SetTopWindow(frame) return true app = MyApp(0) app.MainLoop() Errors (and traceback) /home/wallter/python/Custom Button overlay/src/Custom_Button.py:8: DeprecationWarning: The wxPython compatibility package is no longer automatically generated or actively maintained. Please switch to the wx package as soon as possible. I have never been able to get this to go away whenever using wxPython any help? from wxPython.wx import * Traceback (most recent call last): File "/home/wallter/python/Custom Button overlay/src/Main.py", line 57, in <module> app = MyApp(0) File "/usr/lib/python2.6/dist-packages/wx-2.8-gtk2-unicode/wx/_core.py", line 7978, in __init__ self._BootstrapApp() File "/usr/lib/python2.6/dist-packages/wx-2.8-gtk2-unicode/wx/_core.py", line 7552, in _BootstrapApp return _core_.PyApp__BootstrapApp(*args, **kwargs) File "/home/wallter/python/Custom Button overlay/src/Main.py", line 52, in OnInit frame = MyFrame(NULL, -1, "wxPython | Buttons") File "/home/wallter/python/Custom Button overlay/src/Main.py", line 32, in __init__ wx.Point(200,200), wx.Size(300,100)) TypeError: 'module' object is not callable I have tried removing the "wx.Point(200,200), wx.Size(300,100))" just to have the error move up to the line above. Have I declared it right? help?

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  • Unable to log in to ubuntu server 10.04 after trying to join windows domain

    - by nash
    I was trying to join our ubuntu 10.04 server to the windows domain and I ended up editing the pam.d configuration files. My aim was to have domain users log into the ubuntu server with their domain accounts in order to access some applications instead of creating new unix users each time. My system admin says the join was successful to the domain. Now I have no way of logging into the sever. Is there a way I can undo everything and get the server back to the original login using the local account? I will also appreciate if someone pointed me to some configuration that actually worked - I am still willing to try and make it work.

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  • wxPython - ListCrtl and SQLite3

    - by Dunwitch
    I'm trying to get a SQLite3 DB to populate a wx.ListCrtl. I can get it to print to stdout/stderr without any problem. I just can't seem to figure out how to display the data in the DataWindow/DataList? I'm sure I've made some code mistakes, so any help is appreciated. Main.py import wx import wx.lib.mixins.listctrl as listmix from database import * import sys class DataWindow(wx.Frame): def __init__(self, parent = None): wx.Frame.__init__(self, parent, -1, 'DataList', size=(640,480)) self.win = DataList(self) self.Center() self.Show(True) class DataList(wx.ListCtrl, listmix.ListCtrlAutoWidthMixin, listmix.ColumnSorterMixin): def __init__(self, parent = DataWindow): wx.ListCtrl.__init__( self, parent, -1, style=wx.LC_REPORT|wx.LC_VIRTUAL|wx.LC_HRULES|wx.LC_VRULES) #building the columns self.InsertColumn(0, "Location") self.InsertColumn(1, "Address") self.InsertColumn(2, "Subnet") self.InsertColumn(3, "Gateway") self.SetColumnWidth(0, 100) self.SetColumnWidth(1, 150) self.SetColumnWidth(2, 150) self.SetColumnWidth(3, 150) class MainWindow(wx.Frame): def __init__(self, parent = None, id = -1, title = "MainWindow"): wx.Frame.__init__(self, parent, id, title, size = (800,600), style = wx.DEFAULT_FRAME_STYLE ^ (wx.RESIZE_BORDER)) # StatusBar self.CreateStatusBar() # Filemenu filemenu = wx.Menu() # Filemenu - About menuitem = filemenu.Append(-1, "&About", "Information about this application") self.Bind(wx.EVT_MENU, self.onAbout, menuitem) #Filemenu - Data menuitem = filemenu.Append(-1, "&Data", "Get data") self.Bind(wx.EVT_MENU, self.onData, menuitem) # Filemenu - Seperator filemenu.AppendSeparator() #Filemenu - Exit menuitem = filemenu.Append(-1, "&Exit", "Exit the application") self.Bind(wx.EVT_MENU, self.onExit, menuitem) # Menubar menubar = wx.MenuBar() menubar.Append(filemenu, "&File") self.SetMenuBar(menubar) # Show self.Show(True) self.Center() def onAbout(self, event): pass def onData(self, event): DataWindow(self) callDb = Database() sql = "SELECT rowid, address, subnet, gateway FROM pod1" records = callDb.select(sql) for v in records: print "How do I get the records on the DataList?" #print "%s%s%s" % (v[1],v[2],v[3]) #for v in records: #DataList.InsertStringItem("%s") % (v[0], v[1], v[2]) def onExit(self, event): self.Close() self.Destroy() def onSave(self, event): pass if __name__ == '__main__': app = wx.App() frame = MainWindow(None, -1) frame.Show() app.MainLoop() database.py import os import sqlite3 class Database(object): def __init__(self, db_file="data/data.sqlite"): database_allready_exists = os.path.exists(db_file) self.db = sqlite3.connect(db_file) if not database_allready_exists: self.setupDefaultData() def select(self,sql): cursor = self.db.cursor() cursor.execute(sql) records = cursor.fetchall() cursor.close return records def insert(self,sql): newID = 0 cursor = self.db.cursor() cursor.execute(sql) newID = cursor.lastrowid self.db.commit() cursor.close() return newID def save(self,sql): cursor = self.db.cursor() cursor.execute(sql) self.db.commit() cursor.close() def setupDefaultData(self): pass

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  • Will be self-taught limit me?

    - by Isaiah
    I'm 21 and am pretty efficient in html/css, python, and javascript. I also know my way around lisp languages and enjoy programing in them. My problem is that I'm extremely self-taught and not quite confident that I could land a job programing, but I really need a job soon as I've just become a father. I haven't even created a resume yet because I'm not really sure what to put on it except my lone experience. So I wanted to ask, will being primarily self-taught with some experience on small projects I've done for a few clients limit me too much? I mean I know I need some kind of education so I've enrolled part time in a community college to work on a degree in computer science, but it's years till then. And if it will limit me a lot, what kind of skills would be good to work on to make my chances any better? Thank You

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  • Will being self-taught limit me?

    - by Isaiah
    I'm 21 and am pretty efficient in html/css, python, and javascript. I also know my way around lisp languages and enjoy programing in them. My problem is that I'm extremely self-taught and not quite confident that I could land a job programing, but I really need a job soon as I've just become a father. I haven't even created a resume yet because I'm not really sure what to put on it except my lone experience. So I wanted to ask, will being primarily self-taught with some experience on small projects I've done for a few clients limit me too much? I mean I know I need some kind of education so I've enrolled part time in a community college to work on a degree in computer science, but it's years till then. And if it will limit me a lot, what kind of skills would be good to work on to make my chances any better? Thank You

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  • Is there any self-improving compiler around?

    - by JohnIdol
    I am not aware of any self-improving compiler, but then again I am not much of a compiler-guy. Is there ANY self-improving compiler out there? Please note that I am talking about a compiler that improves itself - not a compiler that improves the code it compiles. Any pointers appreciated! Side-note: in case you're wondering why I am asking have a look at this post. Even if I agree with most of the arguments I am not too sure about the following: We have programs that can improve their code without human input now — they’re called compilers. ... hence my question.

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  • Running the same code for get(self) as post(self)

    - by Peter Farmer
    Its been mentioned in other answers about getting the same code running for both the def get(self) and the def post(self) for any given request. I was wondering what techniques people use, I was thinking of: class ListSubs(webapp.RequestHandler): def get(self): self._run() def post(self): self._run() def _run(self): self.response.out.write("This works nicely!")

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  • How do I create a self referential association (self join) in a single class using ActiveRecord in Rails?

    - by Daniel Chang
    I am trying to create a self join table that represents a list of customers who can refer each other (perhaps to a product or a program). I am trying to limit my model to just one class, "Customer". The schema is: create_table "customers", force: true do |t| t.string "name" t.integer "referring_customer_id" t.datetime "created_at" t.datetime "updated_at" end add_index "customers", ["referring_customer_id"], name: "index_customers_on_referring_customer_id" My model is: class Customer < ActiveRecord::Base has_many :referrals, class_name: "Customer", foreign_key: "referring_customer_id", conditions: {:referring_customer_id => :id} belongs_to :referring_customer, class_name: "Customer", foreign_key: "referring_customer_id" end I have no problem accessing a customer's referring_customer: @customer.referring_customer.name ... returns the name of the customer that referred @customer. However, I keep getting an empty array when accessing referrals: @customer.referrals ... returns []. I ran binding.pry to see what SQL was being run, given a customer who has a "referer" and should have several referrals. This is the SQL being executed. Customer Load (0.3ms) SELECT "customers".* FROM "customers" WHERE "customers"."id" = ? ORDER BY "customers"."id" ASC LIMIT 1 [["id", 2]] Customer Exists (0.2ms) SELECT 1 AS one FROM "customers" WHERE "customers"."referring_customer_id" = ? AND "customers"."referring_customer_id" = 'id' LIMIT 1 [["referring_customer_id", 3]] I'm a bit lost and am unsure where my problem lies. I don't think my query is correct -- @customer.referrals should return an array of all the referrals, which are the customers who have @customer.id as their referring_customer_id.

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  • How to JOIN a COUNT from a table, and then effect that COUNT with another JOIN

    - by jakenoble
    Hi I have three tables Post ID Name 1 'Something' 2 'Something else' 3 'One more' Comment ID PostId ProfileID Comment 1 1 1 'Hi my name is' 2 2 2 'I like cakes' 3 3 3 'I hate cakes' Profile ID Approved 1 1 2 0 3 1 I want to count the comments for a post where the profile for the comment is approved I can select the data from Post and then join a count from Comment fine. But this count should be dependent on if the Profile is approved or not. The results I am expecting is CommentCount PostId Count 1 1 2 0 3 1 Thanks for any help.

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  • SQL Join query help

    - by lostInTransit
    Hi I have 2 tables A and B with the following columns Table A - id,bId,aName,aVal Table B - id,bName where A.bId is the same as B.id. I want a result set from a query to get A.id, A.aName, B.bName where A.bId=B.id OR A.id, A.aName, "" when A.bId=0. In both cases, only those records should be considered where A.aVal LIKE "aVal" Can someone please help me with the query? I can use left join but how do I get the blank string if bId=0 and B.bName otherwise? Thanks

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  • Join using combined conditions on one join table

    - by Nathan Wienert
    I have join a table joining songs to genres. The table has a 'source' column that's used to identify where the genre was found. Genres are found from blogs, artists, tags, and posts. So, songs | song_genre | genres id | song_id, source, genre_id | id What I want to build is a song SELECT query that works something like this, given I already have a genre_id: IF exists song_genre with source='artist' AND a song_genre with source='blog' OR exists song_genre with source='artist' AND a song_genre with source='post' OR exists song_genre with source='tag' I'm was going to do it by doing a bunch of joins, but am sure I'm not doing it very well. Using Postgres 9.1.

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  • MS SQL 2008, join or no join?

    - by Patrick
    Just a small question regarding joins. I have a table with around 30 fields and i was thinking about making a second table to store 10 of those fields. Then i would just join them in with the main data. The 10 fields that i was planning to store in a second table does not get queried directly, it's just some settings for the data in the first table. Something like: Table 1 Id Data1 Data2 Data3 etc ... Table 2 Id (same id as table one) Settings1 Settings2 Settings3 Is this a bad solution? Should i just use 1 table? How much performance inpact does it have? All entries in table 1 would also then have an entry in table 2. Small update is in order. Most of the Data fields are of the type varchar and 2 of them are of the type text. How is indexing treated? My plan is to index 2 data fields, email (varchar 50) and author (varchar 20). And yes, all records in Table 1 will have a record in Table 2. Most of the settings fields are of the bit type, around 80%. The rest is a mix between int and varchar. The varchars can be null.

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  • SQL Server 2008, join or no join?

    - by Patrick
    Just a small question regarding joins. I have a table with around 30 fields and i was thinking about making a second table to store 10 of those fields. Then i would just join them in with the main data. The 10 fields that i was planning to store in a second table does not get queried directly, it's just some settings for the data in the first table. Something like: Table 1 Id Data1 Data2 Data3 etc ... Table 2 Id (same id as table one) Settings1 Settings2 Settings3 Is this a bad solution? Should i just use 1 table? How much performance inpact does it have? All entries in table 1 would also then have an entry in table 2. Small update is in order. Most of the Data fields are of the type varchar and 2 of them are of the type text. How is indexing treated? My plan is to index 2 data fields, email (varchar 50) and author (varchar 20). And yes, all records in Table 1 will have a record in Table 2. Most of the settings fields are of the bit type, around 80%. The rest is a mix between int and varchar. The varchars can be null.

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  • Hopcroft–Karp algorithm in Python

    - by Simon
    I am trying to implement the Hopcroft Karp algorithm in Python using networkx as graph representation. Currently I am as far as this: #Algorithms for bipartite graphs import networkx as nx import collections class HopcroftKarp(object): INFINITY = -1 def __init__(self, G): self.G = G def match(self): self.N1, self.N2 = self.partition() self.pair = {} self.dist = {} self.q = collections.deque() #init for v in self.G: self.pair[v] = None self.dist[v] = HopcroftKarp.INFINITY matching = 0 while self.bfs(): for v in self.N1: if self.pair[v] and self.dfs(v): matching = matching + 1 return matching def dfs(self, v): if v != None: for u in self.G.neighbors_iter(v): if self.dist[ self.pair[u] ] == self.dist[v] + 1 and self.dfs(self.pair[u]): self.pair[u] = v self.pair[v] = u return True self.dist[v] = HopcroftKarp.INFINITY return False return True def bfs(self): for v in self.N1: if self.pair[v] == None: self.dist[v] = 0 self.q.append(v) else: self.dist[v] = HopcroftKarp.INFINITY self.dist[None] = HopcroftKarp.INFINITY while len(self.q) > 0: v = self.q.pop() if v != None: for u in self.G.neighbors_iter(v): if self.dist[ self.pair[u] ] == HopcroftKarp.INFINITY: self.dist[ self.pair[u] ] = self.dist[v] + 1 self.q.append(self.pair[u]) return self.dist[None] != HopcroftKarp.INFINITY def partition(self): return nx.bipartite_sets(self.G) The algorithm is taken from http://en.wikipedia.org/wiki/Hopcroft%E2%80%93Karp_algorithm However it does not work. I use the following test code G = nx.Graph([ (1,"a"), (1,"c"), (2,"a"), (2,"b"), (3,"a"), (3,"c"), (4,"d"), (4,"e"),(4,"f"),(4,"g"), (5,"b"), (5,"c"), (6,"c"), (6,"d") ]) matching = HopcroftKarp(G).match() print matching Unfortunately this does not work, I end up in an endless loop :(. Can someone spot the error, I am out of ideas and I must admit that I have not yet fully understand the algorithm, so it is mostly an implementation of the pseudo code on wikipedia

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  • GAE Datastore Put()

    - by Ivan Slaughter
    def post(self): update = self.request.get('update') if users.get_current_user(): if update: personal = db.GqlQuery("SELECT * FROM Personal WHERE __key__ = :1", db.Key(update)) personal.name = self.request.get('name') personal.gender = self.request.get('gender') personal.mobile_num = self.request.get('mobile_num') personal.birthdate = int(self.request.get('birthdate')) personal.birthplace = self.request.get('birthplace') personal.address = self.request.get('address') personal.geo_pos = self.request.get('geo_pos') personal.info = self.request.get('info') photo = images.resize(self.request.get('img'), 0, 80) personal.photo = db.Blob(photo) personal.put() self.redirect('/admin/personal') else: personal= Personal() personal.name = self.request.get('name') personal.gender = self.request.get('gender') personal.mobile_num = self.request.get('mobile_num') personal.birthdate = int(self.request.get('birthdate')) personal.birthplace = self.request.get('birthplace') personal.address = self.request.get('address') personal.geo_pos = self.request.get('geo_pos') personal.info = self.request.get('info') photo = images.resize(self.request.get('img'), 0, 80) personal.photo = db.Blob(photo) personal.put() self.redirect('/admin/personal') else: self.response.out.write('I\'m sorry, you don\'t have permission to add this LP Personal Data.') Should this will update the existing record if the 'update' is querystring containing key datastore key. I try this but keep adding new record/entity. Please give me some sugesstion to correctly updating the record/entity. Correction? : def post(self): update = self.request.get('update') if users.get_current_user(): if update: personal = Personal.get(db.Key(update)) personal.name = self.request.get('name') personal.gender = self.request.get('gender') personal.mobile_num = self.request.get('mobile_num') personal.birthdate = int(self.request.get('birthdate')) personal.birthplace = self.request.get('birthplace') personal.address = self.request.get('address') personal.geo_pos = self.request.get('geo_pos') personal.info = self.request.get('info') photo = images.resize(self.request.get('img'), 0, 80) personal.photo = db.Blob(photo) personal.put() self.redirect('/admin/personal') else: personal= Personal() personal.name = self.request.get('name') personal.gender = self.request.get('gender') personal.mobile_num = self.request.get('mobile_num') personal.birthdate = int(self.request.get('birthdate')) personal.birthplace = self.request.get('birthplace') personal.address = self.request.get('address') personal.geo_pos = self.request.get('geo_pos') personal.info = self.request.get('info') photo = images.resize(self.request.get('img'), 0, 80) personal.photo = db.Blob(photo) personal.put() self.redirect('/admin/personal') else: self.response.out.write('I\'m sorry, you don\'t have permission to add this LP Personal Data.')

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  • Objective-C I can access self.view but not self.view.frame

    - by user292896
    I can access and show self.view and see the frame in the log but when I try to access self.view.frame I get null. Below is the log output of NSLog(@"Show self.view:%@",self.view); NSLog(@"Show self.view.frame:%@",self.view.frame); - 2010-03-28 11:08:43.373 vivmed_CD_Tab[20356:207] Show self.view:<UITableView: 0x4001600; frame = (0 0; 320 583); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x3b21270>> 2010-03-28 11:08:43.373 vivmed_CD_Tab[20356:207] Show self.view.frame:(null) Can anyone explain why self.view.frame is null but self.view shows a frame? May Goal is to change the frame size. Cheers, Grant

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  • Basics of Join Factorization

    - by Hong Su
    We continue our series on optimizer transformations with a post that describes the Join Factorization transformation. The Join Factorization transformation was introduced in Oracle 11g Release 2 and applies to UNION ALL queries. Union all queries are commonly used in database applications, especially in data integration applications. In many scenarios the branches in a UNION All query share a common processing, i.e, refer to the same tables. In the current Oracle execution strategy, each branch of a UNION ALL query is evaluated independently, which leads to repetitive processing, including data access and join. The join factorization transformation offers an opportunity to share the common computations across the UNION ALL branches. Currently, join factorization only factorizes common references to base tables only, i.e, not views. Consider a simple example of query Q1. Q1:    select t1.c1, t2.c2    from t1, t2, t3    where t1.c1 = t2.c1 and t1.c1 > 1 and t2.c2 = 2 and t2.c2 = t3.c2   union all    select t1.c1, t2.c2    from t1, t2, t4    where t1.c1 = t2.c1 and t1.c1 > 1 and t2.c3 = t4.c3; Table t1 appears in both the branches. As does the filter predicates on t1 (t1.c1 > 1) and the join predicates involving t1 (t1.c1 = t2.c1). Nevertheless, without any transformation, the scan (and the filtering) on t1 has to be done twice, once per branch. Such a query may benefit from join factorization which can transform Q1 into Q2 as follows: Q2:    select t1.c1, VW_JF_1.item_2    from t1, (select t2.c1 item_1, t2.c2 item_2                   from t2, t3                    where t2.c2 = t3.c2 and t2.c2 = 2                                  union all                   select t2.c1 item_1, t2.c2 item_2                   from t2, t4                    where t2.c3 = t4.c3) VW_JF_1    where t1.c1 = VW_JF_1.item_1 and t1.c1 > 1; In Q2, t1 is "factorized" and thus the table scan and the filtering on t1 is done only once (it's shared). If t1 is large, then avoiding one extra scan of t1 can lead to a huge performance improvement. Another benefit of join factorization is that it can open up more join orders. Let's look at query Q3. Q3:    select *    from t5, (select t1.c1, t2.c2                  from t1, t2, t3                  where t1.c1 = t2.c1 and t1.c1 > 1 and t2.c2 = 2 and t2.c2 = t3.c2                 union all                  select t1.c1, t2.c2                  from t1, t2, t4                  where t1.c1 = t2.c1 and t1.c1 > 1 and t2.c3 = t4.c3) V;   where t5.c1 = V.c1 In Q3, view V is same as Q1. Before join factorization, t1, t2 and t3 must be joined first before they can be joined with t5. But if join factorization factorizes t1 from view V, t1 can then be joined with t5. This opens up new join orders. That being said, join factorization imposes certain join orders. For example, in Q2, t2 and t3 appear in the first branch of the UNION ALL query in view VW_JF_1. T2 must be joined with t3 before it can be joined with t1 which is outside of the VW_JF_1 view. The imposed join order may not necessarily be the best join order. For this reason, join factorization is performed under cost-based transformation framework; this means that we cost the plans with and without join factorization and choose the cheapest plan. Note that if the branches in UNION ALL have DISTINCT clauses, join factorization is not valid. For example, Q4 is NOT semantically equivalent to Q5.   Q4:     select distinct t1.*      from t1, t2      where t1.c1 = t2.c1  union all      select distinct t1.*      from t1, t2      where t1.c1 = t2.c1 Q5:    select distinct t1.*     from t1, (select t2.c1 item_1                   from t2                union all                   select t2.c1 item_1                  from t2) VW_JF_1     where t1.c1 = VW_JF_1.item_1 Q4 might return more rows than Q5. Q5's results are guaranteed to be duplicate free because of the DISTINCT key word at the top level while Q4's results might contain duplicates.   The examples given so far involve inner joins only. Join factorization is also supported in outer join, anti join and semi join. But only the right tables of outer join, anti join and semi joins can be factorized. It is not semantically correct to factorize the left table of outer join, anti join or semi join. For example, Q6 is NOT semantically equivalent to Q7. Q6:     select t1.c1, t2.c2    from t1, t2    where t1.c1 = t2.c1(+) and t2.c2 (+) = 2  union all    select t1.c1, t2.c2    from t1, t2      where t1.c1 = t2.c1(+) and t2.c2 (+) = 3 Q7:     select t1.c1, VW_JF_1.item_2    from t1, (select t2.c1 item_1, t2.c2 item_2                  from t2                  where t2.c2 = 2                union all                  select t2.c1 item_1, t2.c2 item_2                  from t2                                                                                                    where t2.c2 = 3) VW_JF_1       where t1.c1 = VW_JF_1.item_1(+)                                                                  However, the right side of an outer join can be factorized. For example, join factorization can transform Q8 to Q9 by factorizing t2, which is the right table of an outer join. Q8:    select t1.c2, t2.c2    from t1, t2      where t1.c1 = t2.c1 (+) and t1.c1 = 1 union all    select t1.c2, t2.c2    from t1, t2    where t1.c1 = t2.c1(+) and t1.c1 = 2 Q9:   select VW_JF_1.item_2, t2.c2   from t2,             (select t1.c1 item_1, t1.c2 item_2            from t1            where t1.c1 = 1           union all            select t1.c1 item_1, t1.c2 item_2            from t1            where t1.c1 = 2) VW_JF_1   where VW_JF_1.item_1 = t2.c1(+) All of the examples in this blog show factorizing a single table from two branches. This is just for ease of illustration. Join factorization can factorize multiple tables and from more than two UNION ALL branches.  SummaryJoin factorization is a cost-based transformation. It can factorize common computations from branches in a UNION ALL query which can lead to huge performance improvement. 

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  • nHibernate Self Join Mapping

    - by kmoo01
    Hi Guys, This is probably incredibly simple, but I just cant see the wood for the trees at the moment. For brevity, I would like to model a word object, that has related words to it (synonyms), In doing so I could have the following mappings: <class name="Word" table="bs_word"> <id name="Id" column="WordId" type="Int32" unsaved-value="-1"> <generator class="native"> <param name="sequence"></param> </generator> </id> <property name="Key" column="word" type="String" length="50" /> <many-to-one name="SynonymGroup" class="BS.Core.Domain.Synonym, BS.Core" column="SynonymId" lazy="false"/> <class name="Synonym" table="bs_Synonym"> <id name="Id" column="SynonymId" type="Int32" unsaved-value="-1"> <generator class="native"> <param name="sequence"></param> </generator> </id> <property name="Alias" column="Alias" type="String" length="50" /> <bag name="Words" cascade="none" lazy="false" inverse="true"> <key column="SynonymId" /> <one-to-many class="Word" /> </bag> Mapping it like this would mean for a given word, I can access related words (synonyms) like this: word.SynonymGroup.Words However I would like to know if it is possible to map a bag of objects on an instance of a word object...if that makes sense, so I can access the related words like this: word.Words I've tried playing around with the map element, and composite elements, all to no avail - so I was wondering if some kind person could point me in the right direction? ta, kmoo01

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  • App Engine webapp.RequestHandler child instances has no self.request during __init__

    - by grucha
    i use modified webapp.RequestHandler for handling requests in my app: class MyRequestHandler(webapp.RequestHandler): """ Request handler with some facilities like user. self.out is the dictionary to pass to templates """ def __init__(self, *args, **kwargs): super(MyRequestHandler, self).__init__(*args, **kwargs) self.out = { 'user': users.get_current_user(), 'logout_url': users.create_logout_url(self.request.uri) } def render(self, template_name): """ Shortcut to render templates """ self.response.out.write(template.render(template_name, self.out)) class DeviceList(MyRequestHandler): def get(self): self.out['devices'] = GPSDevice.all().fetch(1000) self.render('templates/device_list.html') but I get an exception: line 28, in __init__ self.out['logout_url'] = users.create_logout_url(self.request.uri) AttributeError: 'DeviceList' object has no attribute 'request' When the code causing exception is moved out of __init__ everything's fine: class MyRequestHandler(webapp.RequestHandler): """ Request handler with some facilities like user. self.out is the dictionary to pass to templates and initially it contains user object for example """ def __init__(self, *args, **kwargs): super(MyRequestHandler, self).__init__(*args, **kwargs) self.out = { 'user': users.get_current_user(), } def render(self, template_name): """ Shortcut to render templates """ self.out['logout_url'] = users.create_logout_url(self.request.uri) self.response.out.write(template.render(template_name, self.out)) Whi is that? Why there's no self.request after parent's (i.e. webapp.RequestHandler's) __init__ was executed?

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  • How to replace a Widget with another using Qt ?

    - by Natim
    Hi, I have an QHBoxLayout with a QTreeWidget on the left, a separator on the middle and a widget on the right. When I click on the QTreeWidget, I want to change the widget on the right to modify the QTreeWidgetItem I tried to do this with this code : def new_rendez_vous(self): self.ui.horizontalLayout_4.removeWidget(self.ui.editionFormWidget) del self.ui.editionFormWidget self.ui.editionFormWidget = RendezVousManagerDialog(self.parent) self.ui.editionFormWidget.show() self.ui.horizontalLayout_4.addWidget(self.ui.editionFormWidget) self.connect(self.ui.editionFormWidget, QtCore.SIGNAL('saved'), self.scheduleTreeWidget.updateData) def edit(self, category, rendez_vous): self.ui.horizontalLayout_4.removeWidget(self.ui.editionFormWidget) del self.ui.editionFormWidget self.ui.editionFormWidget = RendezVousManagerDialog(self.parent, category, rendez_vous) self.ui.editionFormWidget.show() self.ui.horizontalLayout_4.addWidget(self.ui.editionFormWidget) self.connect(self.ui.editionFormWidget, QtCore.SIGNAL('saved'), self.scheduleTreeWidget.updateData) def edit_category(self, category): self.ui.horizontalLayout_4.removeWidget(self.ui.editionFormWidget) del self.ui.editionFormWidget self.ui.editionFormWidget = CategoryManagerDialog(self.parent, category) self.ui.editionFormWidget.show() self.ui.horizontalLayout_4.addWidget(self.ui.editionFormWidget) self.connect(self.ui.editionFormWidget, QtCore.SIGNAL('saved'), self.scheduleTreeWidget.updateData) But it doesn't work and all the widgets are stacked up on each other : . Do you know how I can remove the old widget and next display the new one ?

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  • Performing Inner Join for Multiple Columns in the Same Table

    - by frankiefrank
    I have a scenario which I'm a bit stuck on. Let's say I have a survey about colors, and I have one table for the color data, and another for people's answers. tbColors color_code , color_name 1 , 'blue' 2 , 'green' 3 , 'yellow' 4 , 'red' tbAnswers answer_id , favorite_color , least_favorite_color , color_im_allergic_to 1 , 1 , 2 3 2 , 3 , 1 4 3 , 1 , 1 2 4 , 2 , 3 4 For display I want to write a SELECT that presents the answers table but using the color_name column from tbColors. I understand the "most stupid" way to do it naming tbColors three times in the FROM section, using a different alias for each column to replace. How would a non-stupid way look?

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  • Edit of self referencing HABTM in cakephp works, sometimes

    - by Odegard
    I'm using a self referencing HABTM model with Participants. You sign up for an event and when you log in to your reservation/profile you see a list of other participants and you can choose to add yourself and others into various groups; share hotel room, share transportation from airport etc. What I've managed so far: 1) In my profile I see the list of all other participants with checkboxes. Great so far. 2) Adding another participant works fine. Next time I edit, the participant I added is shown as checked. 3) Removing another participant works fine too as long as you still have checked participants before you submit! Again, with words: There are 3 participants. I'm logged in as one of them, and I see the 2 other people on the participants list. I choose to check both of them. This works fine (always). Later I choose to remove one of them (by unchecking the checkbox and hitting submit). This also works fine (always). If I want to remove the last checkbox... nothing is updated (always!). What's curious is that I can add and remove any odd combination of participants and it will always work UNLESS I choose to remove every participants in one go (removing a one and only participant is a special case of "remove all checked participants"). As far as I know, HABTMs work by first deleting all relations, then re-saving them. I can see that in my tables when I remove, add, remove, add the same participant over and over again - the id on the HABTM table is always increasing. When I deselect all participants at once, however, the relations are not updated. The ids stay the same, so it's like the save never happened. This behaviour is so specific and peculiar, I have a feeling I'm missing something obvious here. Anyway, here's the relevant code: Model class Participant extends AppModel { var $hasAndBelongsToMany = array( 'buddy' = array( 'className' = 'Participant', 'joinTable' = 'participants_participants', 'foreignKey' = 'participant_id', 'associationForeignKey' = 'buddy_id', 'unique' = true, ) ); Controller function edit($id = null) { if (!$id && empty($this-data)) { $this-Session-setFlash(__('Invalid Participant', true)); $this-redirect(array('action'='index')); } if (!empty($this-data)) { if ($this-Participant-saveAll($this-data)) { $this-Session-setFlash(__('The Participant has been saved', true)); $this-redirect(array('action'='index')); } else { $this-Session-setFlash(__('The Participant could not be saved. Please, try again.', true)); } } if (empty($this-data)) { $this-data = $this-Participant-read(null, $id); } // Fetching all participants except yourself $allParticipants = $this-Participant-find('list', array('conditions' = array('participant.id ' = $id))); // Fetching every participant that has added you to their list $allBuddies = $this-Participant-ParticipantsParticipant-find('list', array( 'conditions' = array('buddy_id' = $id), 'fields' = 'ParticipantsParticipant.participant_id', 'order' = 'ParticipantsParticipant.participant_id ASC' )); $this-set(compact('allParticipants','allBuddies')); } View echo $form-create('Participant'); echo $associations-habtmCheckBoxes($allParticipants, $this-data['buddy'], 'buddy', 'div', '\'border: 1px solid #000;\'', '\'border: 1px solid #000;\''); echo $form-end('Submit'); I'm using a slightly modified helper, habtmCheckBoxes, found here: http://cakeforge.org/snippet/detail.php?type=snippet&id=190 It works like this: function habtmCheckBoxes($rows=array(), $selectedArr=array(), $modelName, $wrapTag='p', $checkedDiv, $uncheckedDiv) {}

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  • Utility that helps in file locking - expert tips wanted

    - by maix
    I've written a subclass of file that a) provides methods to conveniently lock it (using fcntl, so it only supports unix, which is however OK for me atm) and b) when reading or writing asserts that the file is appropriately locked. Now I'm not an expert at such stuff (I've just read one paper [de] about it) and would appreciate some feedback: Is it secure, are there race conditions, are there other things that could be done better … Here is the code: from fcntl import flock, LOCK_EX, LOCK_SH, LOCK_UN, LOCK_NB class LockedFile(file): """ A wrapper around `file` providing locking. Requires a shared lock to read and a exclusive lock to write. Main differences: * Additional methods: lock_ex, lock_sh, unlock * Refuse to read when not locked, refuse to write when not locked exclusivly. * mode cannot be `w` since then the file would be truncated before it could be locked. You have to lock the file yourself, it won't be done for you implicitly. Only you know what lock you need. Example usage:: def get_config(): f = LockedFile(CONFIG_FILENAME, 'r') f.lock_sh() config = parse_ini(f.read()) f.close() def set_config(key, value): f = LockedFile(CONFIG_FILENAME, 'r+') f.lock_ex() config = parse_ini(f.read()) config[key] = value f.truncate() f.write(make_ini(config)) f.close() """ def __init__(self, name, mode='r', *args, **kwargs): if 'w' in mode: raise ValueError('Cannot open file in `w` mode') super(LockedFile, self).__init__(name, mode, *args, **kwargs) self.locked = None def lock_sh(self, **kwargs): """ Acquire a shared lock on the file. If the file is already locked exclusively, do nothing. :returns: Lock status from before the call (one of 'sh', 'ex', None). :param nonblocking: Don't wait for the lock to be available. """ if self.locked == 'ex': return # would implicitly remove the exclusive lock return self._lock(LOCK_SH, **kwargs) def lock_ex(self, **kwargs): """ Acquire an exclusive lock on the file. :returns: Lock status from before the call (one of 'sh', 'ex', None). :param nonblocking: Don't wait for the lock to be available. """ return self._lock(LOCK_EX, **kwargs) def unlock(self): """ Release all locks on the file. Flushes if there was an exclusive lock. :returns: Lock status from before the call (one of 'sh', 'ex', None). """ if self.locked == 'ex': self.flush() return self._lock(LOCK_UN) def _lock(self, mode, nonblocking=False): flock(self, mode | bool(nonblocking) * LOCK_NB) before = self.locked self.locked = {LOCK_SH: 'sh', LOCK_EX: 'ex', LOCK_UN: None}[mode] return before def _assert_read_lock(self): assert self.locked, "File is not locked" def _assert_write_lock(self): assert self.locked == 'ex', "File is not locked exclusively" def read(self, *args): self._assert_read_lock() return super(LockedFile, self).read(*args) def readline(self, *args): self._assert_read_lock() return super(LockedFile, self).readline(*args) def readlines(self, *args): self._assert_read_lock() return super(LockedFile, self).readlines(*args) def xreadlines(self, *args): self._assert_read_lock() return super(LockedFile, self).xreadlines(*args) def __iter__(self): self._assert_read_lock() return super(LockedFile, self).__iter__() def next(self): self._assert_read_lock() return super(LockedFile, self).next() def write(self, *args): self._assert_write_lock() return super(LockedFile, self).write(*args) def writelines(self, *args): self._assert_write_lock() return super(LockedFile, self).writelines(*args) def flush(self): self._assert_write_lock() return super(LockedFile, self).flush() def truncate(self, *args): self._assert_write_lock() return super(LockedFile, self).truncate(*args) def close(self): self.unlock() return super(LockedFile, self).close() (the example in the docstring is also my current use case for this) Thanks for having read until down here, and possibly even answering :)

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  • Please guide this self-taught Web Developer.

    - by ChickenPuke
    One of the major regrets in life is that I didn't do something with my introversion. I didn't manage to get past the first year of college because of that. I have chosen the path where there are no video games and other time sinks, all I have is the internet to quench my thirst of learning the ins and outs of the field of Web Developing/Designing. Though currently, I'm taking a Web Design Associate course at one of the best Computer Arts and this is the last month of the class. Even though I'm still a sapling, I love this field so much. So basically, At school I'm learning web design while at home I'm teaching myself web-developing. First thing first, returning to college seems impossible at the moment because of some financial problems. I'm pretty comfortable with CSS and HTML and I'm into PHP/MySQL at the moment. Could you please provide me a web-development Curriculum to follow. And do I need to learn about the theories behind? And I think I'm still young(I'm 18 at the time of writing). Is it a good thing or bad thing for choosing this path? I'm glad with my decision but in all honesty, I'm worrying about my future and employment because I'm an undergrad, coming from a country where companies are degree b!tches, it saddens me so. Thank you. (My questions are the bold parts. )

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