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  • How would I UPDATE these table entries with SQL and PHP?

    - by CT
    I am working on an Asset Database problem. I enter assets into a database. Every object is an asset and has variables within the asset table. An object is also a type of asset. In this example the type is server. Here is the Query to retrieve all necessary data: SELECT asset.id ,asset.company ,asset.location ,asset.purchaseDate ,asset.purchaseOrder ,asset.value ,asset.type ,asset.notes ,server.manufacturer ,server.model ,server.serialNumber ,server.esc ,server.warranty ,server.user ,server.prevUser ,server.cpu ,server.memory ,server.hardDrive FROM asset LEFT JOIN server ON server.id = asset.id WHERE asset.id = '$id' I then assign all results into single php variables. How would I write a query/script to update an asset?

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  • How to efficiently SELECT rows from database table based on selected set of values

    - by Chau Chee Yang
    I have a transaction table of 1 million rows. The table has a field name "Code" to keep customer's ID. There are about 10,000 different customer code. I have an GUI interface allow user to render a report from transaction table. User may select arbitrary number of customers for rendering. I use IN operator first and it works for few customers: SELECT * FROM TRANS_TABLE WHERE CODE IN ('...', '...', '...') I quickly run into problem if I select few thousand customers. There is limitation using IN operator. An alternate way is create a temporary table with only one field of CODE, and inject selected customer codes into the temporary table using INSERT statement. I may then using SELECT A.* FROM TRANS_TABLE A INNER JOIN TEMP B ON (A.CODE=B.CODE) This works nice for huge selection. However, there is performance overhead for temporary table creation, INSERT injection and dropping of temporary table. Do you aware of better solution to handle this situation?

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  • Programatically Determining Bin Path

    - by Andy
    I'm working on a web app called pj and there is a bin file and a src folder. The relative paths before I deploy the app will look something like: pj/bin and pj/src/pj/script.py. However, after deployment, the relative paths will look like: pj_dep/deployed/bin and pj_dep/deployed/lib/python2.6/site-packages/pj/script.py Question: Within script.py, I am trying to find the path of a file in the bin directory. This leads to 2 different behaviors in the dev and deployment environment. If I do os.path.join(os.path.dirname(__file__), 'bin') to try to get the path for the dev environment, I will have a different path for the deployment environment. Is there a more generalized way I can find the bin directory so that I do not need to rely on an if statement to determine how many directories to go up based on the current env? This doesn't seem flexible and might cause other issues later on when the code is moved.

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  • POST with HTTPBuilder -> NullPointerException?

    - by Stefan Kendall
    I'm trying to make a simple HTTP POST request, and I have no idea why the following is failing. I tried following the examples here, and I don't see where I'm going wrong. Exception java.lang.NullPointerException at groovyx.net.http.HTTPBuilder$RequestConfigDelegate.setBody(HTTPBuilder.java:1131) ... Code def List<String> search(String query, int maxResults) { def http = new HTTPBuilder("mywebsite") http.request(POST) { uri.path = '/search/' body = [string1: "", query: "test"] requestContentType = URLENC headers.'User-Agent' = 'Mozilla/5.0 Ubuntu/8.10 Firefox/3.0.4' response.success = { resp, InputStreamReader reader -> assert resp.statusLine.statusCode == 200 String data = reader.readLines().join() println data } } [] }

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  • Implementing ma? osx loop device driver.

    - by Inso Reiges
    Hello, I am aware that there is a native implementation of loop device system on osx, the hdiutil/hdix driver. But due to a number of reasons i need to roll out my own custom loop driver. Since hdix is closed-source can anyone give some starting pointers, links, advises, etc. on the subject? I had expirience implementing loop drivers on linux and windows but i don't really have a clue where to start from on osx. The basic functionality i need to implement is the same: given any file on disk, simulate a virtual block device interface for it. I also would like my loop driver to use all the native partition filter stacking available for real and hdix virtual block devices on osx.

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  • SQL for selecting only the last item from a versioned table

    - by Jeremy
    I have a table with the following structure: CREATE TABLE items ( id serial not null, title character varying(255), version_id integer DEFAULT 1, parent_id integer, CONSTRAINT items_pkey PRIMARY KEY (id) ) So the table contains rows that looks as so: id: 1, title: "Version 1", version_id: 1, parent_id: 1 id: 2, title: "Version 2", version_id: 2, parent_id: 1 id: 3, title: "Completely different record", version_id: 1, parent_id: 3 This is the SQL code I've got for selecting out all of the records with the most recent version ids: select * from items inner join ( select parent_id, max(version_id) as version_id from items group by parent_id) as vi on items.version_id = vi.version_id and items.parent_id = vi.parent_id Is there a way to write that SQL statement so that it doesn't use a subselect?

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  • Visual Studio error on valid SQL

    - by Sam
    I'm getting an annoying error in visual studio for SQL that executes fine. SELECT InvoiceLines.LineID, InvoiceLines.InvoiceID, InvoiceLines.Text, InvoiceLines.Rate, InvoiceLines.Count, InvoiceLines.Rate * InvoiceLines.Count AS LineTotal, ((InvoiceLines.Rate * InvoiceLines.Count) * (1 + Invoices.VatRate / 100)) * (1 - CAST(Invoices.Discount AS money) * InvoiceLines.ApplyDiscount / 100) AS LineTotalIncVat, InvoiceLines.ApplyDiscount FROM InvoiceLines LEFT JOIN Invoices ON Invoices.InvoiceID = InvoiceLines.InvoiceID What LineTotalIncVat is trying to do is compute the total for the invoice item while adding the vat and subtracting the discount, and yes, probably better to do this in code (would if I could) The error visual studio gives is: There was an error parsing the query [token line number =1, token line offset =14, token in error = InvoiceLines] Even though it will validate and execute without a problem in the query builder...

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  • accessing files after setup.py install

    - by Matthew
    I'm developing a python application and have a question regarding coding it so that it still works after an user has installed it on his or her machine via setup.py install or similar. In one of my files, I use the following: file = "TestParser/View/MainWindow.ui" cwd = os.getcwd() argv_path = os.path.dirname(sys.argv[0]) file_path = os.path.join(cwd, argv_path, file) in order to get the path to MainWindow.ui, when I only know the path relative to the main script's location. This works regardless of from where I call the main script. The issue is that after an user installs the application on his or her machine, the relative path is different, so this doesn't work. I could use __file__, but according to this, py2exe doesn't have __file__. Is there a standard way of achieving this? Or a better way?

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  • complex mysql query problem

    - by Scarface
    Hey guys I have a query that selects data and organizes but not in the correct order. What I want to do is select all the comments for a user in that week and sort it by each topic, then sort the cluster by the latest timestamp of each comment in their respective cluster. My current query selects the right data, but in seemingly random order. Does anyone have any ideas? select * from ( SELECT topic.topic_title, topic.topic_id FROM comments JOIN topic ON topic.topic_id=comments.topic_id WHERE comments.user='$user' AND comments.timestamp>$week order by comments.timestamp desc) derived_table group by topic_id

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  • Converting delimited string to multiple values in mysql

    - by epo
    I have a mysql legacy table which contains an client identifier and a list of items, the latter as a comma-delimited string. E.g. "xyz001", "foo,bar,baz". This is legacy stuff and the user insists on being able to edit a comma delimited string. They now have a requirement for a report table with the above broken into separate rows, e.g. "xyz001", "foo" "xyz001", "bar" "xyz001", "baz" Breaking the string into substrings is easily doable and I have written a procedure to do this by creating a separate table, but that requires triggers to deal with deletes, updates and inserts. This query is required rarely (say once a month) but has to be absolutely up to date when it is run, so e.g. the overhead of triggers is not warranted and scheduled tasks to create the table might not be timely enough. Is there any way to write a function to return a table or a set so that I can join the identifier with the individual items on demand?

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  • finding numbers of days between two date to make a dynamic columns

    - by Chandradyani
    Dear all, I have a select query that currently produces the following results: DoctorName Team 1 2 3 4 5 6 7 ... 31 Visited dr. As   A                             x    x ...      2 times dr. Sc   A                          x          ...      1 times dr. Gh   B                                  x ...      1 times dr. Nd   C                                     ... x    1 times Using the following query: DECLARE @startDate = '1/1/2010', @enddate = '1/31/2010' SELECT d.doctorname, t.teamname, MAX(CASE WHEN ca.visitdate = 1 THEN 'x' ELSE NULL END) AS 1, MAX(CASE WHEN ca.visitdate = 2 THEN 'x' ELSE NULL END) AS 2, MAX(CASE WHEN ca.visitdate = 3 THEN 'x' ELSE NULL END) AS 3, ... MAX(CASE WHEN ca.visitdate = 31 THEN 'x' ELSE NULL END) AS 31, COUNT(*) AS visited FROM CACTIVITY ca JOIN DOCTOR d ON d.id = ca.doctorid JOIN TEAM t ON t.id = ca.teamid WHERE ca.visitdate BETWEEN @startdate AND @enddate GROUP BY d.doctorname, t.teamname the problem is I want to make the column of date are dynamic for example if ca.visitdate BETWEEN '2/1/2012' AND '2/29/2012' so the result will be : DoctorName Team 1 2 3 4 5 6 7 ... 29 Visited dr. As   A                             x    x ...      2 times dr. Sc   A                          x          ...      1 times dr. Gh   B                                  x ...      1 times dr. Nd   C                                     ... x    1 times Can somebody help me how to get numbers of days between two date and help me revised the query so it can looping MAX(CASE WHEN ca.visitdate = 1 THEN 'x' ELSE NULL END) AS 1 as many as numbers of days? Please please

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  • Database error when deleting entry in my rails app.

    - by Danny McClelland
    Hi Everyone...again! I have almost everything in my Rails app working, with the exception of detroying entries. I can destroy entries for companies but not kases and people. The following error show when trying to do so: SQLite3::SQLException: no such column: kases_people.kase_id: SELECT * FROM "kases" INNER JOIN "kases_people" ON "kases".id = "kases_people".kase_id WHERE ("kases_people".person_id = 5 ) I suspect this is an error with the party model for the has_many :through associations that I dont fully understand. You can find an up to date version of the app at www.github.com/dannyweb/surveycontrol Thanks, Danny

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  • How to program critical section for reader-writer systems?

    - by Srinivas Nayak
    Hi, Lets say, I have a reader-writer system where reader and writer are concurrently running. 'a' and 'b' are two shared variables, which are related to each other, so modification to them needs to be an atomic operation. A reader-writer system can be of the following types: rr ww r-w r-ww rr-w rr-ww where [ r : single reader rr: multiple reader w : single writer ww: multiple writer ] Now, We can have a read method for a reader and a write method for a writer as follows. I have written them system type wise. rr read_method { read a; read b; } ww write_method { lock(m); write a; write b; unlock(m); } r-w r-ww rr-w rr-ww read_method { lock(m); read a; read b; unlock(m); } write_method { lock(m); write a; write b; unlock(m); } For multiple reader system, shared variable access doesn't need to be atomic. For multiple writer system, shared variable access need to be atomic, so locked with 'm'. But, for system types 3 to 6, is my read_method and write_method correct? How can I improve? Sincerely, Srinivas Nayak

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  • Recommendations for 'C' Project architecture guidelines?

    - by SiegeX
    Now that I got my head wrapped around the 'C' language to a point where I feel proficient enough to write clean code, I'd like to focus my attention on project architecture guidelines. I'm looking for a good resource that coves the following topics: How to create an interface that promotes code maintainability and is extensible for future upgrades. Library creation guidelines. Example, when should I consider using static vs dynamic libraries. How to properly design an ABI to cope with either one. Header files: what to partition out and when. Examples on when to use 1:1 vs 1:many .h to .c Anything you feel I missed but is important when attempting to architect a new C project. Ideally, I'd like to see some example projects ranging from small to large and see how the architecture changes depending on project size, function or customer. What resource(s) would you recommend for such topics?

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  • Error : while creating a file.

    - by Harikrishna
    I am storing records of datatable to csv file with the help of the following code : // we'll use these to check for rows with nulls var columns = yourTable.Columns .Cast<DataColumn>(); using (var writer = new StreamWriter(yourPath)) { for (int i = 0; i < yourTable.Rows.Count; i++) { DataRow row = yourTable.Rows[i]; // check for any null cells if (columns.Any(column => row.IsNull(column))) continue; string[] textCells = row.ItemArray .Select(cell => cell.ToString()) // may need to pick a text qualifier here .ToArray(); // check for non-null but EMPTY cells if (textCells.Any(text => string.IsNullOrEmpty(text))) continue; writer.WriteLine(string.Join(",", textCells)); } } But I get the error like System.UnauthorizedAccessException was unhandled Message="Access to the path 'D:\\Harikrishna\\Monthly Reports' is denied." What can be the problem and solution ?

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  • LLBL Gen Predicate Filter

    - by Neil
    I am new to LLBLGen Pro and am checking for duplicate, I have the following SQL: SQL: select a.TopicId,atc.TopicCategoryId,a.Headline from article a inner join ArticleTopicCategory atc on atc.ArticleId = a.Id where a.TopicId = 'C0064FAE-093B-466E-8745-230534867D2F' and a.Headline = 'Test' and atc.TopicCategoryId in ('004D64F7-474C-48F9-9887-17B1E7532A84') Whenever I step though my function, it always returns 0: LLBLGen Code: public bool CheckDuplicateArticle(Guid topicId, List<Guid> categories, string headline) { ArticleCollection articles = new ArticleCollection(); PredicateExpression filter = new PredicateExpression(); RelationCollection relation = new RelationCollection(); relation.Add(ArticleEntity.Relations.ArticleTopicCategoryEntityUsingArticleId); filter.AddWithAnd(ArticleFields.TopicId == topicId); filter.AddWithAnd(ArticleTopicCategoryFields.Id == categories); filter.AddWithAnd(ArticleFields.Headline == headline); articles.GetMulti(filter, 0, null, relation); return articles.Count > 0; } Any help would be appreciated!

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  • SQL: select random row from table where the ID of the row isn't in another table?

    - by johnrl
    I've been looking at fast ways to select a random row from a table and have found the following site: http://74.125.77.132/search?q=cache:http://jan.kneschke.de/projects/mysql/order-by-rand/&hl=en&strip=1 What I want to do is to select a random url from my table 'urls' that I DON'T have in my other table 'urlinfo'.The query I am using now selects a random url from 'urls' but I need it modified to only return a random url that is NOT in the 'urlinfo' table. Heres the query: SELECT url FROM urls JOIN (SELECT CEIL(RAND() * (SELECT MAX(urlid) FROM urls ) ) AS urlid ) AS r2 USING(urlid); And the two tables: CREATE TABLE urls ( urlid INT NOT NULL AUTO_INCREMENT PRIMARY KEY, url VARCHAR(255) NOT NULL, ) ENGINE=INNODB; CREATE TABLE urlinfo ( urlid INT NOT NULL PRIMARY KEY, urlinfo VARCHAR(10000), FOREIGN KEY (urlid) REFERENCES urls (urlid) ) ENGINE=INNODB;

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  • Entity-attribute-value model using codeigniter / php

    - by John Stewart
    SO I am trying to create a way to structure my database to be able customize forms. I looked into EAV pattern and here is my db structure: Table form - form_id - form_name - form_added_on - form_modified_at Table: form_fields - field_id - form_id - field_type (TEXT, RADIO etc..) - field_default_value - field_required Table: form_data - data_id - field_id - form_id - field_value so now I can store any custom form into the database and if I want to get the values for an individual form I can simply join it by "form_id" .. the problem: I want to be able to search through all the forms for a specific field value. How can I do that with EAV model? Also, I thought about just storing the custom data as a serialized (JSON) object but then I am not sure how can I query that data. Please note that I am using Codeigniter with MYSQL. So if conversation can use Codeigniter libraries if needed.

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  • mySQL one-to-many query

    - by Stomped
    I've got 3 tables that are something like this (simplified here ofc): users user_id user_name info info_id user_id rate contacts contact_id user_id contact_data users has a one-to-one relationship with info, although info doesn't always have a related entry. users has a one-to-many relationship with contacts, although contacts doesn't always have related entries. I know I can grab the proper 'users' + 'info' with a left join, is there a way to get all the data I want at once? For example, one returned record might be: user_id: 5 user_name: tom info_id: 1 rate: 25.00 contact_id: 7 contact_data: 555-1212 contact_id: 8 contact_data: 555-1315 contact_id: 9 contact_data: 555-5511 Is this possible with a single query? Or must I use multiple?

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  • Is possible to auto-import a module from a diferent subfolder in other subfolder?

    - by mamcx
    I have a kind of plugin system, with this layout: - Python -- SDK -- Plugins ---- Plugin1 ---- Plugin2 All 3 have a __init__.py file. I wonder if is possible to be able to do import SDK from any plugin (as if SDK was in the site-packages folder). I'm in a situation where need to deploy, update, delete, add or change SDK files or any of the plugins under non-admin accounts, and wonder if I can get SDK in a clean way (I could sys.path.append in all plugins but I wonder if exist a better option). I imagine that using this in the Plugins init coulkd work: import sys import os ROOT_DIR = os.path.abspath(os.path.join(os.path.dirname(__file__),'..')) print ROOT_DIR sys.path.append( ROOT_DIR ) But clearly is not executed this code (I imagine init was auto-magicalled executed in the load of the module :( )

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  • HowTo init Django model, before using it?

    - by mosg
    Hi. I'm new to python and django. Apps | Versions: Python 2.6.2 Django (working with PostgreSQL) Question: I wrote a simple model: class OperationType(models.Model): eid = models.IntegerField(unique=True) name = models.CharField(max_length=64) def __unicode__(self): tpl = 'eid="', str(self.eid), '" name="', self.name, '"' return ''.join(tpl) Now I need to initialize it, for example with this data: 0, "None" 1, "Add" 2, "Edit" 3, "Delete" But I need to initialize this data not with admin web panel, but after class model created in the same code. How to do this? Thanks for help!

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  • Custom validation works in development but not in unit test

    - by Geolev
    I want to validate that at least one of two columns have a value in my model. I found somewhere on the web that I could create a custom validator as follows: # Check for the presence of one or another field: # :validates_presence_of_at_least_one_field :last_name, :company_name - would require either last_name or company_name to be filled in # also works with arrays # :validates_presence_of_at_least_one_field :email, [:name, :address, :city, :state] - would require email or a mailing type address module ActiveRecord module Validations module ClassMethods def validates_presence_of_at_least_one_field(*attr_names) msg = attr_names.collect {|a| a.is_a?(Array) ? " ( #{a.join(", ")} ) " : a.to_s}.join(", ") + "can't all be blank. At least one field must be filled in." configuration = { :on => :save, :message => msg } configuration.update(attr_names.extract_options!) send(validation_method(configuration[:on]), configuration) do |record| found = false attr_names.each do |a| a = [a] unless a.is_a?(Array) found = true a.each do |attr| value = record.respond_to?(attr.to_s) ? record.send(attr.to_s) : record[attr.to_s] found = !value.blank? end break if found end record.errors.add_to_base(configuration[:message]) unless found end end end end end I put this in a file called lib/acs_validator.rb in my project and added "require 'acs_validator'" to my environment.rb. This does exactly what I want. It works perfectly when I manually test it in the development environment but when I write a unit test it breaks my test environment. This is my unit test: require 'test_helper' class CustomerTest < ActiveSupport::TestCase # Replace this with your real tests. test "the truth" do assert true end test "customer not valid" do puts "customer not valid" customer = Customer.new assert !customer.valid? assert customer.errors.invalid?(:subdomain) assert_equal "Company Name and Last Name can't both be blank.", customer.errors.on(:contact_lname) end end This is my model: class Customer < ActiveRecord::Base validates_presence_of :subdomain validates_presence_of_at_least_one_field :customer_company_name, :contact_lname, :message => "Company Name and Last Name can't both be blank." has_one :service_plan end When I run the unit test, I get the following error: DEPRECATION WARNING: Rake tasks in vendor/plugins/admin_data/tasks, vendor/plugins/admin_data/tasks, and vendor/plugins/admin_data/tasks are deprecated. Use lib/tasks instead. (called from /usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/tasks/rails.rb:10) Couldn't drop acs_test : #<ActiveRecord::StatementInvalid: PGError: ERROR: database "acs_test" is being accessed by other users DETAIL: There are 1 other session(s) using the database. : DROP DATABASE IF EXISTS "acs_test"> acs_test already exists NOTICE: CREATE TABLE will create implicit sequence "customers_id_seq" for serial column "customers.id" NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "customers_pkey" for table "customers" NOTICE: CREATE TABLE will create implicit sequence "service_plans_id_seq" for serial column "service_plans.id" NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "service_plans_pkey" for table "service_plans" /usr/bin/ruby1.8 -I"lib:test" "/usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake/rake_test_loader.rb" "test/unit/customer_test.rb" "test/unit/service_plan_test.rb" "test/unit/helpers/dashboard_helper_test.rb" "test/unit/helpers/customers_helper_test.rb" "test/unit/helpers/service_plans_helper_test.rb" /usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/base.rb:1994:in `method_missing_without_paginate': undefined method `validates_presence_of_at_least_one_field' for #<Class:0xb7076bd0> (NoMethodError) from /usr/lib/ruby/gems/1.8/gems/will_paginate-2.3.12/lib/will_paginate/finder.rb:170:in `method_missing' from /home/george/projects/advancedcomfortcs/app/models/customer.rb:3 from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require' from /usr/local/lib/site_ruby/1.8/rubygems/custom_require.rb:31:in `require' from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:158:in `require' from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:265:in `require_or_load' from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:224:in `depend_on' from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.8/lib/active_support/dependencies.rb:136:in `require_dependency' from /usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/initializer.rb:414:in `load_application_classes' from /usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/initializer.rb:413:in `each' from /usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/initializer.rb:413:in `load_application_classes' from /usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/initializer.rb:411:in `each' from /usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/initializer.rb:411:in `load_application_classes' from /usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/initializer.rb:197:in `process' from /usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/initializer.rb:113:in `send' from /usr/lib/ruby/gems/1.8/gems/rails-2.3.8/lib/initializer.rb:113:in `run' from /home/george/projects/advancedcomfortcs/config/environment.rb:9 from ./test/test_helper.rb:2:in `require' from ./test/test_helper.rb:2 from ./test/unit/customer_test.rb:1:in `require' from ./test/unit/customer_test.rb:1 from /usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5:in `load' from /usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5 from /usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5:in `each' from /usr/lib/ruby/gems/1.8/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5 rake aborted! Command failed with status (1): [/usr/bin/ruby1.8 -I"lib:test" "/usr/lib/ru...] (See full trace by running task with --trace) It seems to have stepped on will_paginate somehow. Does anyone have any suggestions? Is there another way to do the validation I'm attempting to do? Thanks, George

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  • Databases design - one link table or multiple link tables?

    - by David
    Hi there, I'm working on a front end for a database where each table essentially has a many to many relationship with all other tables. I'm not a DB admin, just a few basic DB courses. The typical solution in this case, as I understand it, would be multiple link tables to join each 'real' table. Here's what I'm proposing instead: one link table that has foreign key dependencies to all other PKs of the other tables. Is there any reason this could turn out badly in terms of scalability, flexibility, etc down the road?

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  • Deleting objects through foreign key relationship with T-SQL query

    - by LaserBeak
    Looking for a way to write the following LinQ to entities query as a T-SQL statement. repository.ProductShells.Where(x => x.ShellMembers.Any(sm => sm.ProductID == pid)).ToList().ForEach(x => repository.ProductShells.Remove(x)); The below is obviously not correct but I need it to delete respective ProductShell object where any ShellMember contains a ProductID equal to the passed in variable pid. I would presume this would involve a join statement to get the relevant ShellMembers. repository.Database.ExecuteSqlCommand("FROM Shellmembers WHERE ProductID={0} DELETE FK_ProductShell", pid); I have cascade delete enabled for the FK_ShellMembers_ProductShells foreign key, so when I delete the ProductShell it will delete all the ShellMembers that are associated with it. I am going to pass this statement to System.Data.Entity Database.ExecuteSqlCommand method.

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  • Database design and foreign keys: Where should they be added in related tables?

    - by Carvell Fenton
    I have a relatively simple subset of tables in my database for tracking something called sessions. These are academic sessions (think offerings of a particular program). The tables to represent a sessions information are: sessions session_terms session_subjects session_mark_item_info session_marks All of these tables have their own primary keys, and are like a tree, in that sessions have terms, terms have subjects, subjects have mark items, etc. So each on would have at least its "parent's" foreign key. My question is, design wise is it a good idea to include the sessions primary key in the other tables as a foreign key to easily select related session items, or is that too much redundency? If I include the session foreign key (or all parent foreign keys from tables up the heirarchy) in all the tables, I can easily select all the marks for a session. As an example, something like SELECT mark FROM session_marks WHERE sessionID=... If I don't, then I would have to combine selects with something like WHERE something IN (SELECT... Which approach is "more correct" or efficient? Thanks in advance!

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