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  • PostgreSQL - select only when specific multiple apperance in column

    - by Horse SMith
    I'm using PostgreSQL. I have a table with 3 fields person, recipe and ingredient person = creator of the recipe recipe = the recipe ingredient = one of the ingredients in the recipe I want to create a query which results in every person who whenever has added carrot to a recipe, the person must also have added salt to the same recipe. More than one person can have created the recipe, in which case the person who added the ingredient will be credited for adding the ingredient. Sometimes the ingredient is used more than once, even by the same person. If this the table: person1, rec1, carrot person1, rec1, salt person1, rec1, salt person1, rec2, salt person1, rec2, pepper person2, rec1, carrot person2, rec1, salt person2, rec2, carrot person2, rec2, pepper person3, rec1, sugar person3, rec1, carrot Then I want this result: person1 Because this person is the only one who whenever has added carrot also have added salt.

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  • 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?

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  • Multi join query returns to many results and improperly matched

    - by Woot4Moo
    I have the following minimal schema in Oracle: http://sqlfiddle.com/#!4/c1ed0/14 The queries I have run yield too many results and this query: select cat.*, status.*, source.* from cats cat, status status, source source Left OUTER JOIN source source2 on source2.sourceid = 1 Right OUTER JOIN status status2 on status2.isStray =0 order by cat.name will yield incorrect results. What I am expecting is a table that looks like the following however I cannot seem to come up with the correct SQL. NAME AGE LENGTH STATUSID CATSOURCE ISSTRAY SOURCEID CATID Adam 1 25 null null null 1 2 Bill 5 1 null null null null null Charles 7 5 null null null null null Steve 12 15 1 1 1 1 1 In plain English what I am looking for is to return all known cats + their associated cat source + their cat status while retaining null values. The only information I will have is the source that I am curious about. I also only want the cats that have a status of either STRAY or UNKNOWN (null)

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  • Transaction within transaction

    - by user281521
    Hello, I want to know if open a transaction inside another is safe and encouraged? I have a method: def foo(): session.begin try: stuffs except Exception, e: session.rollback() raise e session.commit() and a method that calls the first one, inside a transaction: def bar(): stuffs try: foo() #<<<< there it is :) stuffs except Exception, e: session.rollback() raise e session.commit() if I get and exception on the foo method, all the operations will be rolled back? and everything else will work just fine? thanks!!

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  • Porting Oracle Date Manipulation

    - by Grasper
    I need to port this following from Oracle syntax to Postgresql. Both FLO_END_DT and FLO_START_DATE are of type DATE in Oracle, and TIMESTAMP WITHOUT TIME ZONE in Postgresql: SELECT TRUNC( TO_CHAR(ROUND(( FL.FLO_END_DT- FL.FLO_START_DT)* 24), '9999D99'),2) FROM FLOWS FL I am not familiar enough with Oracle to know what it is trying to accomplish. Any ideas?

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  • 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

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  • 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

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  • iPhone - Create non-persistent entities in core data

    - by ncohen
    Hi everyone, I would like to use entity objects but not store them... I read that I could create them like this: myElement = (Element *)[NSEntityDescription insertNewObjectForEntityForName:@"Element" inManagedObjectContext:managedObjectContext]; And right after that remove them: [managedObjectContext deleteObject:myElement]; then I can use my elements: myElement.property1 = @"Hello"; This works pretty well even though I think this is probably not the most optimal way to do it... Then I try to use it in my UITableView... the problem is that the object get released after the initialization. My table becomes empty when I move it! Thanks edit: I've also tried to copy the element ([myElement copy]) but I get an error...

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  • Decimal rounding strategies in enterprise applications

    - by Sapphire
    Well, I am wondering about a thing with rounding decimals, and storing them in DB. Problem is like this: Let's say we have a customer and a invoice. The invoice has total price of $100.495 (due to some discount percentage which is not integer number), but it is shown as $100.50 (when rounded, just for print on invoice). It is stored in the DB with the price of $100.495, which means that when customer makes a deposit of $100.50 it will have $0.005 extra on the account. If this is rounded, it will appear as $0, but after couple of invoices it would keep accumulating, which would appear wrong (although it actually is not). What is best to do in this case. Store the value of $100.50, or leave everything as-is?

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  • How to connect 2 mysql tables with 2 connection string

    - by denonth
    Hi all I need to connect 2 tables from 2 mysql databases that have 2 different connection strings and each is on the different server. I have this query: cmd = new MySqlCommand(String.Format("INSERT INTO {0} (a,b,c,d) SELECT (a,b,c,d) FROM {1}", ConfigSettings.ReadSetting("main_table"), ConfigSettings.ReadSetting("main_table")), con); So both table have the same columns. Thats why I have only one ConfigSettings.ReadSetting("main_table") for both of them as they are same. I have 2 connection strings and each is pointing to their server: con.ConnectionString = ConfigurationManager.ConnectionStrings["con1"].ConnectionString; con2.ConnectionString = ConfigurationManager.ConnectionStrings["con2"].ConnectionString; How to make this cmd to be workking with 2 different connection strings and with the same name for the table. Table name will change that's why it is saved in config.

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  • Sencha : how to pass parameter to php using Ext.data.HttpProxy?

    - by Lauraire Jérémy
    I have successfully completed this great tutorial : http://www.sencha.com/learn/ext-js-grids-with-php-and-sql/ I just can't use the baseParams field specified with the proxy... Here is my code that follows tutorial description : __ My Store : Communes.js ____ Ext.define('app.store.Communes', { extend: 'Ext.data.Store', id: 'communesstore', requires: ['app.model.Commune'], config: { model: 'app.model.Commune', departement:'var', // the proxy with POST method proxy: new Ext.data.HttpProxy({ url: 'app/php/communes.php', // File to connect to method: 'POST' }), // the parameter passed to the proxy baseParams:{ departement: "VAR" }, // the JSON parser reader: new Ext.data.JsonReader({ // we tell the datastore where to get his data from rootProperty: 'results' }, [ { name: 'IdCommune', type: 'integer' }, { name: 'NomCommune', type: 'string' } ]), autoLoad: true, sortInfo:{ field: 'IdCommune', direction: "ASC" } } }); _____ The php file : communes.php _____ <?php /** * CREATE THE CONNECTION */ mysql_connect("localhost", "root", "pwd") or die("Could not connect: " . mysql_error()); mysql_select_db("databasename"); /** * INITIATE THE POST */ $departement = 'null'; if ( isset($_POST['departement'])){ $departement = $_POST['departement']; // Get this from Ext } getListCommunes($departement); /** * */ function getListCommunes($departement) { [CODE HERE WORK FINE : just a connection and query but $departement is NULL] } ?> There is no parameter passed as POST method... Any idea?

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  • How to make notification to group users with read/unread flag?

    - by user2335065
    I am making a notification system so that when users in a group perform an action, it will notify all the other users in the group. I want the notification to be marked "read" or "unread" for each user of the group. With that, I can easily retreive any unread notification for a user and display it. I am think about creating a notification table that have the following fields. +----------------------+ | notification | +----------------------+ | id | | userid | | content | | status (read/unread) | | time | +----------------------+ My question is: Whether it is the correct way of making the system? As it means that when there is 1,000 users in a group, then I have to insert 1,000 rows to the table. If not, what is the better way of doing this? If it is the way to do this, how can I write the php/mysql codes to do the looping of inserting the rows? Thanks!

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  • Multiple has_many's of the same model

    - by Koning Baard
    I have these models: Person has_many :messages_form_person, :foreign_key => :from_user_id, :class_name => :messages has_many :messages_to_person, :foreign_key => :to_user_id, :class_name => :messages Message belongs_to :to_person, :foreign_key => :to_user_id, :class_name => :person belongs_to :from_person, :foreign_key => :to_user_id, :class_name => :person And this view: person#show <% @person.messages_to_person.each do |message| %> <%=h message.title %> <% end %> But I get this error: TypeError in People#show Showing app/views/people/show.html.erb where line #26 raised: can't convert Symbol into String Extracted source (around line #26): 23: <%=h @person.biography %> 24: </p> 25: 26: <% @person.messages_to_person.each do |message| %> 27: 28: <% end %> 29: I basicly want that people can send eachother messages. Can anyone help me? Thanks.

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  • .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?

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  • Correct Sql Script for Formula

    - by Madan Madan
    Can anyone help me write SQL script for the following formula? If DEP = 1 If DROP 1 PLV = 334.86 * exp(0.3541 * ACTIVE_DAYS) + 0.25 * DROP + 20 * DEP Else If DROP < 0 PLV = DROP + 70 * ACTIVE_DAYS Else PLV = 0.25 * DROP + 70 * ACTIVE_DAYS The SQL script which I have is the following SELECT IF(dep=1, if(dep=1, (334.86 * exp(0.3541 * act_days)) + (0.25 * 'drop') + (20 * dep), if('drop'<0, 'drop' + (70 * act_days), (0.25 * 'drop') + (70 * act_days))),'0') as PLV But the above query is not right as something is missing where the formula says Else PLV = 0.26 * DROP Thanks,

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  • 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.

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