Search Results

Search found 32538 results on 1302 pages for 'restore database'.

Page 336/1302 | < Previous Page | 332 333 334 335 336 337 338 339 340 341 342 343  | Next Page >

  • Django: How/Where to store a value for a session without unnecessary DB hits

    - by GerardJP
    Hi all, I have an extended userprofile with AUTH_PROFILE_MODULE (ref: http://tinyurl.com/yhracqq) I would like to set a user.is_guru() method similar to user.is_active(). This would results for al views (or rather templates) to e.g. disable/enable certain user messages, displaying of widgets, etc. The boolean is stored in the extended user profile model, but I want to avoid hitting the DB for every view. So the questions is .. Do I use a context_processor, a template tag, session_dict or what have you to, possible cached, store this info for the duration of the users visit. Note: I dont have performance issues, so it's definitely filed under premature optimization. I just want to avoid generating extra work in the future :). Any pointers are very welcome. Thanx and greetz! Gerard.

    Read the article

  • has anyone produced an in-memory GIT repository?

    - by Andrew Matthews
    I would like to be able to take advantage of the benefits of GIT (and its workflows), but without the cost of disk access - I just would like to leverage the distributed revision control capabilities of GIT to produce something like a hybrid of memcached and GIT. (preferably in .NET) Is there such a beast out there?

    Read the article

  • How to do left joins with least-n-per-group query?

    - by Nate
    I'm trying to get a somewhat complicated query working and am not having any luck whatsoever. Suppose I have the following tables: cart_items: +--------------------------------------------+ | item_id | cart_id | movie_name | quantity | +--------------------------------------------+ | 0 | 0 | braveheart | 4 | | 1 | 0 | braveheart | 9 | | . | . | . | . | | . | . | . | . | | . | . | . | . | | . | . | . | . | +--------------------------------------------+ movies: +------------------------------+ | movie_id | movie_name | ... | +------------------------------+ | 0 | braveheart | . | | . | . | . | | . | . | . | | . | . | . | | . | . | . | +------------------------------+ pricing: +-----------------------------------------+ | id | movie_name | quantity | price_per | +-----------------------------------------+ | 0 | braveheart | 1 | 1.99 | | 1 | braveheart | 2 | 1.50 | | 2 | braveheart | 4 | 1.25 | | 3 | braveheart | 8 | 1.00 | | . | . | . | . | | . | . | . | . | | . | . | . | . | | . | . | . | . | | . | . | . | . | +-----------------------------------------+ I need to join the data from the tables, but with the added complexity that I need to get appropriate price_per from the pricing table. Only one price should be returned for each cart_item, and that should be the lowest price from the pricing table where the quantity for the cart item is at least the quantity in the pricing table. So, the query should return for each item in cart_items the following: +---------------------------------------------+ | item_id | movie_name | quantity | price_per | +---------------------------------------------+ Example 1: Variable passed to the query: cart_id = 0. Return: +---------------------------------------------+ | item_id | movie_name | quantity | price_per | +---------------------------------------------+ | 0 | braveheart | 4 | 1.25 | | 1 | braveheart | 9 | 1.00 | +---------------------------------------------+ Note that this is a minimalist example and that additional data will be pulled from the tables mentioned (particularly the movies table). How could this query be composed? I have tried using left joins and subqueries, but the difficult part is getting the price and nothing I have tried has worked. Thanks for your help. EDIT: I think this is similar to what I have working with my "real" tables: SELECT t1.item_id, t2.movie_name, t1.quantity FROM cart_items t1 LEFT JOIN movies t2 ON t2.movie_name = t1.movie_name WHERE t1.cart_id = 0 Assuming I wrote that correctly (I quickly tried to "port over" my real query), then the output would currently be: +---------------------------------+ | item_id | movie_name | quantity | +---------------------------------+ | 0 | braveheart | 4 | | 1 | braveheart | 9 | +---------------------------------+ The trouble I'm having is joining the price at a certain quantity for a movie. I simply cannot figure out how to do it.

    Read the article

  • "select * into table" Will it work for inserting data into existing table

    - by Shantanu Gupta
    I am trying to insert data from one of my existing table into another existing table. Is it possible to insert data into any existing table using select * into query. I think it can be done using union but in that case i need to record all data of my existing table into temporary table, then drop that table and finally than apply union to insert all records into same table eg. select * into #tblExisting from tblExisting drop table tblExisting select * into tblExisting from #tblExisting union tblActualData Here tblExisting is the table where I actually want to store all data tblActualData is the table from where data is to be appended to tblExisting. Is it right method. Do we have some other alternative ?

    Read the article

  • Question about OOP and objects.

    - by loddn
    I have a school assignment, a Dog Show. My assignment is to create a website where vistors can display results and Judges and Secretary can admin, crud. I have a small problem one part of the assignment. The result should be based on two protokols from different judges and after that checked by the secretary before the result is displayed for the user. I have to say i'm fairly new to programming and so i need some smart suggestions on how to design and implement this. The assignment should cover both a db and c# (.net mvc). Q1: How do i create a object (result)that depends on two other objects(protocol)? Is that even needed? Q2: How to solve this in a relational db?

    Read the article

  • Explain this SQL query in plain English.

    - by Kevinniceguy
    Please explain, in plain English, what question this SQL query answers: SELECT SUM(price) FROM Room r, Hotel h WHERE r.hotelNo = h.hotelNo and hotelName = 'Paris Hilton' and roomNo NOT IN (SELECT roomNo FROM Booking b, Hotel h WHERE (dateFrom <= CURRENT_DATE AND dateTo >= CURRENT_DATE) AND b.hotelNo = h.hotelNo AND hotelName = 'Paris Hilton');

    Read the article

  • .NET Migrations Engine

    - by Karl Seguin
    I was once under the belief that Microsoft was working on an official, ruby-like, Migration framework. However, I haven't been able to find any additional information (or even the original source of my belief). Does anyone know any information about an official migration framework? or possibly an open source one?

    Read the article

  • 2 Select or 1 Join query ?

    - by xRobot
    I have 2 tables: book ( id, title, age ) ---- 100 milions of rows author ( id, book_id, name, born ) ---- 10 millions of rows Now, supposing I have a generic id of a book. I need to print this page: Title: mybook authors: Tom, Graham, Luis, Clarke, George So... what is the best way to do this ? 1) Simple join like this: Select book.title, author.name From book, author WHERE ( author.book_id = book.id ) AND ( book.id = 342 ) 2) For avoid the join, I could make 2 simple query: Select title FROM book WHERE id = 342 Select name FROM author WHERE book_id = 342 What is the most efficient way ?

    Read the article

  • MongoDB or CouchDB - fit for production?

    - by Alan
    I was wondering if anyone can tell me if MongoDB or CouchDB are ready for a production environment. I'm now looking at these storage solutions (I'm favouring MongoDB at the moment), however these projects are quite young and so I foresee that I'm going to have to work quite hard to convince my manager that we should adopt this new technology. What I'd like to know is: 1) Who is using MongoDB or CouchDB today in a production environment? 2) How are you using MongoDB/CouchDB? 3) What problems (if any) did you come across when you adopted this new storage mechanism (and how did you overcome them)? 4) How did you deal with any migration issues that you had to deal with? 5) Do you have any good/bad experiences with either of these solutions that you'd like to share? Thanks.

    Read the article

  • Multiple values in a column

    - by Adnan
    Hi I need some advice regarding multiple records. I have a table with fields username,*message* and message_to. the scenario could be of sending same message to multiple users in a go. What do you suggest? will it be efficient to save all recipients in a single column with comma separated values or I add multiple entries ? Thanks /A

    Read the article

  • IF I have multiple candidate keys which one is a primary key and justify your choice ??

    - by zahrani
    Given R = { Account , Analyst , Assets, Broker, Client, Commission, Company, Dividend, Exchange, Investment, Office, Profile, Return, Risk_profile, Stock, Volume} and a set of functional dependencies F{fd1, fd2,fd3, fd4, fd5,fd6, fd7, fd8, fd9, fd10, fd11} where: fd1: Client - Office fd2: Stock - Exchange, Dividend fd3: Broker - Profile fd4: Company - Stock fd5: Client - Risk_profile, Analyst fd6: Analyst - Broker fd7: Stock, Broker - Invenstment, Volume fd8: Stock - Company fd9: Investment,Commission - Return fd10: Stock, Broker - Client fd11: Account - Assests these are candidate key(s) : (Account, Commission,Analyst ,Company) (Account, Commission,Analyst ,Stock) (Account ,Commission,Broker ,Company) (Account ,Commission,Broker ,Stock) (Account ,Commission,Client, Company) (Account ,Commission,Client ,Stock) (Q) Select a primary key and justify your choice ? I was select (Account ,Commission,Broker ,Stock) as a primary key ??? I chose that because it has the most direct dependencies compared to other ones. e.g. more attributes are functionally dependent on this primary key. please check if my answer is it true ? or Not I'm waiting your answer asap thank you

    Read the article

  • how to join 3 relational tables

    - by orioncabbar
    Hello there, how to join 3 relational tables with the structure: t1 | id t2 | id | rating t3 | source_id | relation t3 stores the data of a field which t1 and t2 uses both. so source_id field can be t1's id or t2's id. input : t1 id output : t2 rating an example: **t1** id | --------- 42 | **t2** id | rating ------------- 37 | 9.2 **t3** id | source_id -------------- 42 | 1 37 | 1 26 | 2 23 | 1 what i want is to get 9.2 output with 42 input. can you do that in one sql query?

    Read the article

  • minimal cover for functional dependencies

    - by user2975836
    I have the following problem: AB -> CD H->B G ->DA CD-> EF A -> HJ J>G I understand the first step (break down right hand side) and get the following results: AB -> C AB -> D H -> B G -> D G -> A CD -> E CD -> F A -> H A -> J J -> G I understand that A - h and h - b, therefore I can remove the B from AB - c and ab - D, to get: A -> C A -> D H -> B G -> D G -> A CD -> E CD -> F A -> H A -> J J -> G The step that follows is what I can't compute (reduce the left hand side) Any help will be greatly appreciated.

    Read the article

  • ruby on rails has_many through relationship

    - by BennyB
    Hi i'm having a little trouble with a has_many through relationship for my app and was hoping to find some help. So i've got Users & Lectures. Lectures are created by one user but then other users can then "join" the Lectures that have been created. Users have their own profile feed of the Lectures they have created & also have a feed of Lectures friends have created. This question however is not about creating a lecture but rather "Joining" a lecture that has been created already. I've created a "lecturerelationships" model & controller to handle this relationship between Lectures & the Users who have Joined (which i call "actives"). Users also then MUST "Exit" the Lecture (either by clicking "Exit" or navigating to one of the header navigation links). I'm grateful if anyone can work through some of this with me... I've got: Users.rb model Lectures.rb model Users_controller Lectures_controller then the following model lecturerelationship.rb class lecturerelationship < ActiveRecord::Base attr_accessible :active_id, :joinedlecture_id belongs_to :active, :class_name => "User" belongs_to :joinedlecture, :class_name => "Lecture" validates :active_id, :presence => true validates :joinedlecture_id, :presence => true end lecturerelationships_controller.rb class LecturerelationshipsController < ApplicationController before_filter :signed_in_user def create @lecture = Lecture.find(params[:lecturerelationship][:joinedlecture_id]) current_user.join!(@lecture) redirect_to @lecture end def destroy @lecture = Lecturerelationship.find(params[:id]).joinedlecture current_user.exit!(@user) redirect_to @user end end Lectures that have been created (by friends) show up on a users feed in the following file _activity_item.html.erb <li id="<%= activity_item.id %>"> <%= link_to gravatar_for(activity_item.user, :size => 200), activity_item.user %><br clear="all"> <%= render :partial => 'shared/join', :locals => {:activity_item => activity_item} %> <span class="title"><%= link_to activity_item.title, lecture_url(activity_item) %></span><br clear="all"> <span class="user"> Joined by <%= link_to activity_item.user.name, activity_item.user %> </span><br clear="all"> <span class="timestamp"> <%= time_ago_in_words(activity_item.created_at) %> ago. </span> <% if current_user?(activity_item.user) %> <%= link_to "delete", activity_item, :method => :delete, :confirm => "Are you sure?", :title => activity_item.content %> <% end %> </li> Then you see I link to the the 'shared/join' partial above which can be seen in the file below _join.html.erb <%= form_for(current_user.lecturerelationships.build(:joinedlecture_id => activity_item.id)) do |f| %> <div> <%= f.hidden_field :joinedlecture_id %> </div> <%= f.submit "Join", :class => "btn btn-large btn-info" %> <% end %> Some more files that might be needed: config/routes.rb SampleApp::Application.routes.draw do resources :users do member do get :following, :followers, :joined_lectures end end resources :sessions, :only => [:new, :create, :destroy] resources :lectures, :only => [:create, :destroy, :show] resources :relationships, :only => [:create, :destroy] #for users following each other resources :lecturerelationships, :only => [:create, :destroy] #users joining existing lectures So what happens is the lecture comes in my activity_feed with a Join button option at the bottom...which should create a lecturerelationship of an "active" & "joinedlecture" (which obviously are supposed to be coming from the user & lecture classes. But the error i get when i click the join button is as follows: ActiveRecord::StatementInvalid in LecturerelationshipsController#create SQLite3::ConstraintException: constraint failed: INSERT INTO "lecturerelationships" ("active_id", "created_at", "joinedlecture_id", "updated_at") VALUES (?, ?, ?, ?) Also i've included my user model (seems the error is referring to it) user.rb class User < ActiveRecord::Base attr_accessible :email, :name, :password, :password_confirmation has_secure_password has_many :lectures, :dependent => :destroy has_many :lecturerelationships, :foreign_key => "active_id", :dependent => :destroy has_many :joined_lectures, :through => :lecturerelationships, :source => :joinedlecture before_save { |user| user.email = email.downcase } before_save :create_remember_token validates :name, :presence => true, :length => { :maximum => 50 } VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i validates :email, :presence => true, :format => { :with => VALID_EMAIL_REGEX }, :uniqueness => { :case_sensitive => false } validates :password, :presence => true, :length => { :minimum => 6 } validates :password_confirmation, :presence => true def activity # This feed is for "My Activity" - basically lectures i've started Lecture.where("user_id = ?", id) end def friendactivity Lecture.from_users_followed_by(self) end # lECTURE TO USER (JOINING) RELATIONSHIPS def joined?(selected_lecture) lecturerelationships.find_by_joinedlecture_id(selected_lecture.id) end def join!(selected_lecture) lecturerelationships.create!(:joinedlecture_id => selected_lecture.id) end def exit!(selected_lecture) lecturerelationships.find_by_joinedlecture_id(selected_lecture.id).destroy end end Thanks for any and all help - i'll be on here for a while so as mentioned i'd GREATLY appreciate someone who may have the time to work through my issues with me...

    Read the article

  • Growing MS Access File Size problem

    - by user55886
    I have a large MS Access application with a lot of computations in VBA code. When I run it it eventually crashes due to excessive file size. There are a lot of intermediate tables and queries created and subsequently deleted, but Access does not reclaim the space. I have diligently closed all intermediate record sets and set all temporary objects to nothing, but nothing helps. The only way I can get my code to run is to run part of it, stop and repair/compress the file then restart the code. Isn't there a better way? Thanks

    Read the article

  • SQL - get latest records from table where field is unique

    - by 89stevenharris
    I have a table of data as follows id status conversation_id message_id date_created 1 1 1 72 2012-01-01 00:00:00 2 2 1 87 2012-03-03 00:00:00 3 2 2 95 2012-05-05 00:00:00 I want to get all the rows from the table in date_created DESC order, but only one row per conversation_id. So in the case of the example data above, I would want to get the rows with id 2 and 3. Any advice is much appreciated.

    Read the article

  • Scalable way of doing self join with many to many table

    - by johnathan
    I have a table structure like the following: user id name profile_stat id name profile_stat_value id name user_profile user_id profile_stat_id profile_stat_value_id My question is: How do I evaluate a query where I want to find all users with profile_stat_id and profile_stat_value_id for many stats? I've tried doing an inner self join, but that quickly gets crazy when searching for many stats. I've also tried doing a count on the actual user_profile table, and that's much better, but still slow. Is there some magic I'm missing? I have about 10 million rows in the user_profile table and want the query to take no longer than a few seconds. Is that possible?

    Read the article

  • Table for each region in MySQL

    - by King Wu
    There are four regions with more than one million records total. Should I create a table with a region column or a table for each region and combine them to get the top ranks? If I combine all four regions, none of my columns will be unique so I will need to also add an id column for my primary key. Otherwise, name, accountId & characterId would be candidate keys or should I just add an id column anyways. Table: ---------------------------------------------------------------- | name | accountId | iconId | level | characterId | updateDate | ----------------------------------------------------------------

    Read the article

  • Using NVL function in SQL, please help!

    - by user363024
    I'm needing to select first and last name in a table which is working fine in the following SQL, but the part that isn't working is the NVL function. The file should show all pilots at a company that fly helicopters and IF they don't have a licence the field HT_NAME should come up as 'N/A' and the field for end hours flown should be 0. I've put NVL function in as my text details but it still isn't working. Have i made a syntax error? Help would be appreciated. Select E.EMP_NBR, E.EMP_FIRSTNAME || ' ' || E.EMP_LASTNAME, E.EMP_PILOT, ED.HT_NBR, NVL(HT.HT_NAME, 'N/A'), NVL(ED.END_HRS_FLOWN, 0), ED.END_LAST_ANNUAL_REVIEW_DATE From ENDORSEMENT ED, EMPLOYEE E, HELICOPTER_TYPE HT WHERE HT.HT_NBR = ED.HT_NBR (+) ORDER BY ED.END_HRS_FLOWN DESC, E.EMP_FIRSTNAME || ' ' || E.EMP_LASTNAME ASC; should make employees who are not pilots appear with a N/A under heli type and 0 under hours flown. It isn't working - even though I have tried multiple things to repair it.

    Read the article

< Previous Page | 332 333 334 335 336 337 338 339 340 341 342 343  | Next Page >