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  • How do I write this GROUP BY in mysql UNION query

    - by user1652368
    Trying to group the results of two queries together. When I run this query: SELECT pr_id, pr_sbtcode, pr_sdesc, od_quantity, od_amount FROM ( SELECT `bgProducts`.`pr_id`, `bgProducts`.`pr_sbtcode`, `bgProducts`.`pr_sdesc`, SUM(`od_quantity`) AS `od_quantity`, SUM(`od_amount`) AS `od_amount`, MIN(UNIX_TIMESTAMP(`or_date`)) AS `or_date` FROM `bgOrderMain` JOIN `bgOrderData` JOIN `bgProducts` WHERE `bgOrderMain`.`or_id` = `bgOrderData`.`or_id` AND `od_pr` = `pr_id` AND UNIX_TIMESTAMP(`or_date`) >= '1262322000' AND UNIX_TIMESTAMP(`or_date`) <= '1346990399' AND (`pr_id` = '415' OR `pr_id` = '1088') GROUP BY `bgProducts`.`pr_id` UNION SELECT `bgProducts`.`pr_id`, `bgProducts`.`pr_sbtcode`, `bgProducts`.`pr_sdesc`,SUM(`od_quantity`) AS `od_quantity`, SUM(`od_amount`) AS `od_amount`, MIN(UNIX_TIMESTAMP(`or_date`)) AS `or_date` FROM `npOrderMain` JOIN `npOrderData` JOIN `bgProducts` WHERE `npOrderMain`.`or_id` = `npOrderData`.`or_id` AND `od_pr` = `pr_id` AND UNIX_TIMESTAMP(`or_date`) >= '1262322000' AND UNIX_TIMESTAMP(`or_date`) <= '1346990399' AND (`pr_id` = '415' OR `pr_id` = '1088') GROUP BY `bgProducts`.`pr_id` ) TEMPTABLE3; it produces this result +-------+------------+--------------------------+-------------+-----------+ | pr_id | pr_sbtcode | pr_sdesc | od_quantity | od_amount +-------+------------+--------------------------+-------------+-----------+ | 415 | NP13 | Product 13 | 5 | 125 | 1088 | NPAW | Product AW | 4 | 100 | 415 | NP13 | Product 13 | 5 | 125 | 1088 | NPAW | Product AW | 2 | 50 +-------+------------+--------------------------+-------------+-----------+</pre> What I want to get a result that combines those into 2 lines: +-------+------------+--------------------------+-------------+-----------+ | pr_id | pr_sbtcode | pr_sdesc | od_quantity | od_amount +-------+------------+--------------------------+-------------+-----------+ | 415 | NP13 | Product 13 | 10 | 250 | 1088 | NPAW | Product AW | 6 | 150 +-------+------------+--------------------------+-------------+-----------+</pre> So I added GROUP BY pr_id to the end of the query: SELECT pr_id, pr_sbtcode, pr_sdesc, od_quantity, od_amount FROM ( SELECT `bgProducts`.`pr_id`, `bgProducts`.`pr_sbtcode`, `bgProducts`.`pr_sdesc`, SUM(`od_quantity`) AS `od_quantity`, SUM(`od_amount`) AS `od_amount`, MIN(UNIX_TIMESTAMP(`or_date`)) AS `or_date` FROM `bgOrderMain` JOIN `bgOrderData` JOIN `bgProducts` WHERE `bgOrderMain`.`or_id` = `bgOrderData`.`or_id` AND `od_pr` = `pr_id` AND UNIX_TIMESTAMP(`or_date`) >= '1262322000' AND UNIX_TIMESTAMP(`or_date`) <= '1346990399' AND (`pr_id` = '415' OR `pr_id` = '1088') GROUP BY `bgProducts`.`pr_id` UNION SELECT `bgProducts`.`pr_id`, `bgProducts`.`pr_sbtcode`, `bgProducts`.`pr_sdesc`,SUM(`od_quantity`) AS `od_quantity`, SUM(`od_amount`) AS `od_amount`, MIN(UNIX_TIMESTAMP(`or_date`)) AS `or_date` FROM `npOrderMain` JOIN `npOrderData` JOIN `bgProducts` WHERE `npOrderMain`.`or_id` = `npOrderData`.`or_id` AND `od_pr` = `pr_id` AND UNIX_TIMESTAMP(`or_date`) >= '1262322000' AND UNIX_TIMESTAMP(`or_date`) <= '1346990399' AND (`pr_id` = '415' OR `pr_id` = '1088') GROUP BY `bgProducts`.`pr_id` ) TEMPTABLE3 GROUP BY pr_id; But that just gives me this: +-------+------------+--------------------------+-------------+-----------+ | pr_id | pr_sbtcode | pr_sdesc | od_quantity | od_amount +-------+------------+--------------------------+-------------+-----------+ | 415 | NP13 | Product 13 | 5 | 125 | 1088 | NPAW | Product AW | 4 | 100 +-------+------------+--------------------------+-------------+-----------+ What am I missing here??

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  • PyGTK: Manually render an existing widget at a given Rectangle? (TextView in a custom CellRenderer)

    - by NicDumZ
    Hello! I am trying to draw a TextView into the cell of a TreeView. (Why? I would like to have custom tags on text, so they can be clickable and trigger different actions/popup menus depending on where user clicks). I have been trying to write a customized CellRenderer for this purpose, but so far I failed because I find it extremely difficult to find generic documentation on rendering design in gtk. More than an answer at the specific question (that might be hard/not doable, and I'm not expecting you to do everything for me), I am first looking for documentation on how a widget is rendered, to understand how one is supposed to implement a CellRenderer. Can you share any link that explains, either for gtk or for pygtk, the rendering mechanism? More specifically: size allocation mechanism (should I say protocol?). I understand that a window has a defined size, and then queries its children, saying "my size is w x h, what would be your ideal size, buddy?", and then sometimes shrinks children when all children cant fit together at their ideal sizes. Any specific documentation on that, and on particular on when this happens during rendering? How are rendered "builtin" widgets? What kind of methods do they call on Widget base class? On the parent Window? When? Do they use pango.Layout? can you manually draw a TextView onto a pango.Layout object? This link gives an interesting example showing how you can draw content in a pango.Layout object and use it in a CellRenderer. I guess that I could adapt it if only I understood how TextView widget are rendered. Or perhaps, to put it more simply: given an existing widget instance, how does one render it at a specific gdk.Rectangle? Thanks a lot.

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  • Entity Framework not populating context

    - by stimms
    I'm just starting out with some entity framework exploration, I figured it was time to see what everybody was complaining about. I am running into an issue where the entities don't seem to be returning any of the object context. I generated the model from a database with three tables which link to one another. Courses Instructors CanTeach Relationships are as you would expect: a course can relate to multiple CanTeach entities and an instructor can also relate to multiple CanTeach entities. I also added an OData service to my project which also makes use of the same model. So I can run queries like from a in CanTeach where a.Instructor.FirstName == "Barry" select new { Name = a.Instructor.FirstName + " " + a.Instructor.LastName, Course = a.Course.Name} without issue against the OData endpoint using LINQPad. However when I do a simple query like public Instructor GetInstructorFromID(int ID) { return context.Instructors.Where(i => i.ID == ID).FirstOrDefault(); } The CanTeach list is empty. I know everything in EF is lazy loaded and it is possible that my context is out of scope by the time I look at the object context, however even trying to get the object context as soon as the query is run results in and empty object context. What am I doing wrong?

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  • Performance Comparison of Shell Scripts vs high level interpreted langs (C#/Java/etc.)

    - by dferraro
    Hi all, First - This is not meant to be a 'which is better, ignorant nonionic war thread'... But rather, I generally need help in making an architecture decision / argument to put forward to my boss. Skipping the details - I simply just would love to know and find the results of anyone who has done some performance comparisons of Shell vs [Insert General Purpose Programming Language (interpreted) here), such as C# or Java... Surprisingly, I have spent some time on Google on searching here to not find any of this data. Has anyone ever done these comparisons, in different use-cases; hitting a database like in a XYX # of loops doing different types of SQL (Oracle pref, but MSSQL would do) queries such as any of the CRUD ops - and also not hitting database and just regular 50k loop type comparison doing different types of calculations, and things of that nature? In particular - for right now, I need to a comparison of hitting an Oracle DB from a shell script vs, lets say C# (again, any GPPL thats interpreted would be fine, even the higher level ones like Python). But I also need to know about standard programming calculations / instructions/etc... Before you ask 'why not just write a quick test yourself? The answer is: I've been a Windows developer my whole life/career and have very limited knowledge of Shell scripting - not to mention *nix as a whole.... So asking the question on here from the more experienced guys would be grealty beneficial, not to mention time saving as we are in near perputual deadline crunch as it is ;). Thanks so much in advance,

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  • Entity framework with Linq to Entities performance

    - by mare
    If I have a static method like this public static string GetTicClassificationTitle(string classI, string classII, string classIII) { using (TicDatabaseEntities ticdb = new TicDatabaseEntities()) { var result = from classes in ticdb.Classifications where classes.ClassI == classI where classes.ClassII == classII where classes.ClassIII == classIII select classes.Description; return result.FirstOrDefault(); } } and use this method in various places in foreach loops or just plain calling it numerous times, does it create and open new connection every time? If so, how can I tackle this? Should I cache the results somewhere, like in this case, I would cache the entire Classifications table in Memory Cache? And then do queries vs this cached object? Or should I make TicDatabaseEntities variable static and initialize it at class level? Should my class be static if it contains only static methods? Because right now it is not.. Also I've noticed that if I return result.First() instead of FirstOrDefault() and the query does not find a match, it will issue an exception (with FirstOrDefault() there is no exception, it returns null). Thank you for clarification.

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  • Advice on Linq to SQL mapping object design

    - by fearofawhackplanet
    I hope the title and following text are clear, I'm not very familiar with the correct terms so please correct me if I get anything wrong. I'm using Linq ORM for the first time and am wondering how to address the following. Say I have two DB tables: User ---- Id Name Phone ----- Id UserId Model The Linq code generator produces a bunch of entity classes. I then write my own classes and interfaces which wrap these Linq classes: class DatabaseUser : IUser { public DatabaseUser(User user) { _user = user; } public Guid Id { get { return _user.Id; } } ... etc } so far so good. Now it's easy enough to find a users phones from Phones.Where(p => p.User = user) but surely comsumers of the API shouldn't need to be writing their own Linq queries to get at data, so I should wrap this query in a function or property somewhere. So the question is, in this example, would you add a Phones property to IUser or not? In other words, should my interface specifically be modelling my database objects (in which case Phones doesn't belong in IUser), or are they actually simply providing a set of functions and properties which are conceptually associated with a User (in which case it does)? There seems drawbacks to both views, but I'm wondering if there is a standard approach to the problem. Or just any general words of wisdom you could share. My first thought was to use extension methods but in fact that doesn't work in this case.

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  • GridView ObjectDataSource LINQ Paging and Sorting using multiple table query.

    - by user367426
    I am trying to create a pageing and sorting object data source that before execution returns all results, then sorts on these results before filtering and then using the take and skip methods with the aim of retrieving just a subset of results from the database (saving on database traffic). this is based on the following article: http://www.singingeels.com/Blogs/Nullable/2008/03/26/Dynamic_LINQ_OrderBy_using_String_Names.aspx Now I have managed to get this working even creating lambda expressions to reflect the sort expression returned from the grid even finding out the data type to sort for DateTime and Decimal. public static string GetReturnType<TInput>(string value) { var param = Expression.Parameter(typeof(TInput), "o"); Expression a = Expression.Property(param, "DisplayPriceType"); Expression b = Expression.Property(a, "Name"); Expression converted = Expression.Convert(Expression.Property(param, value), typeof(object)); Expression<Func<TInput, object>> mySortExpression = Expression.Lambda<Func<TInput, object>>(converted, param); UnaryExpression member = (UnaryExpression)mySortExpression.Body; return member.Operand.Type.FullName; } Now the problem I have is that many of the Queries return joined tables and I would like to sort on fields from the other tables. So when executing a query you can create a function that will assign the properties from other tables to properties created in the partial class. public static Account InitAccount(Account account) { account.CurrencyName = account.Currency.Name; account.PriceTypeName = account.DisplayPriceType.Name; return account; } So my question is, is there a way to assign the value from the joined table to the property of the current table partial class? i have tried using. from a in dc.Accounts where a.CompanyID == companyID && a.Archived == null select new { PriceTypeName = a.DisplayPriceType.Name}) but this seems to mess up my SortExpression. Any help on this would be much appreciated, I do understand that this is complex stuff.

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  • I have data about deadlocks, but I can't understand why they occur

    - by Alex
    I am receiving a lot of deadlocks in my big web application. http://stackoverflow.com/questions/2941233/how-to-automatically-re-run-deadlocked-transaction-asp-net-mvc-sql-server Here I wanted to re-run deadlocked transactions, but I was told to get rid of the deadlocks - it's much better, than trying to catch the deadlocks. So I spent the whole day with SQL Profiler, setting the tracing keys etc. And this is what I got. There's a Users table. I have a very high usable page with the following query (it's not the only query, but it's the one that causes troubles) UPDATE Users SET views = views + 1 WHERE ID IN (SELECT AuthorID FROM Articles WHERE ArticleID = @ArticleID) And then there's the following query in ALL pages: User = DB.Users.SingleOrDefault(u => u.Password == password && u.Name == username); That's where I get User from cookies. Very often a deadlock occurs and this second Linq-to-SQL query is chosen as a victim, so it's not run, and users of my site see an error screen. I read a lot about deadlocks... And I don't understand why this is causing a deadlock. So obviously both of this queries run very often. At least once a second. Maybe even more often (300-400 users online). So they can be run at the same time very easily, but why does it cause a deadlock? Please help. Thank you

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  • Get the first and last posts in a thread

    - by Grampa
    I am trying to code a forum website and I want to display a list of threads. Each thread should be accompanied by info about the first post (the "head" of the thread) as well as the last. My current database structure is the following: threads table: id - int, PK, not NULL, auto-increment name - varchar(255) posts table: id - int, PK, not NULL, auto-increment thread_id - FK for threads The tables have other fields as well, but they are not relevant for the query. I am interested in querying threads and somehow JOINing with posts so that I obtain both the first and last post for each thread in a single query (with no subqueries). So far I am able to do it using multiple queries, and I have defined the first post as being: SELECT * FROM threads t LEFT JOIN posts p ON t.id = p.thread_id ORDER BY p.id LIMIT 0, 1 The last post is pretty much the same except for ORDER BY id DESC. Now, I could select multiple threads with their first or last posts, by doing: SELECT * FROM threads t LEFT JOIN posts p ON t.id = p.thread_id ORDER BY p.id GROUP BY t.id But of course I can't get both at once, since I would need to sort both ASC and DESC at the same time. What is the solution here? Is it even possible to use a single query? Is there any way I could change the structure of my tables to facilitate this? If this is not doable, then what tips could you give me to improve the query performance in this particular situation?

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  • MySQL: Combining multiple where conditions

    - by Karl
    I'm working on a menu system that takes a url and then queries the db to build the menu. My menu table is: +---------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +---------+--------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | node_id | int(11) | YES | | NULL | | | parent | int(11) | YES | | NULL | | | weight | int(11) | YES | | NULL | | | title | varchar(250) | YES | | NULL | | | alias | varchar(250) | YES | | NULL | | | exclude | int(11) | YES | | NULL | | +---------+--------------+------+-----+---------+----------------+ The relevant columns for my question are alias, parent and node_id. So for a url like: http://example.com/folder1/folder2/filename Alias would potentially = "filename", "folder1", "folder2" Parent = the node_id of the parent folder. What I know is how to split the url up into an array and check the alias for a match to each part. What I don't know is how to have it then filter by parent whose alias matches "folder2" and whose parent alias matches "folder1". I'm imagining a query like so: select * from menu where alias='filename' and where parent = node_id where alias='folder2' and parent = node_id where alias='folder1' Except I know that the above is wrong. I'm hoping this can be done in a single query. Thanks for any help in advance!

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  • wpf progress bar slows 10x times serial port communications... how could be possible that?

    - by D_Guidi
    I know that this could look a dumb question, but here's my problem. I have a worker dialog that "hides" a backgroundworker, so in a worker thread I do my job, I report the progress in a standard way and then I show the results in my WPF program. The dialog contains a simply animated gif and a standard wpf progress bar, and when a progress is notified I set Value property. All lokks as usual and works well for any kind of job, like web service calls, db queries, background elaboration and so on. For my job we use also many "couplers", card readers that reads data from smart card, that are managed with native C code that access to serial port (so, I don't use .NET SerialPort object). I have some nunit tests and I read a sample card in 10 seconds, but using my actual program, under the backgroundworker and showing my worker dialog, I need 1.30 minutes to do the SAME job. I struggled into problem for days until I decide to remove the worker dialog, and without dialog I obtain the same performances of the tests! So I investigated, and It's not the dialog, not the animated gif, but the wpf progress bar! Simply the fact that a progress bar is shown (so, no animation, no Value set called, nothing of nothing) slows serialport communicatitons. Looks incredible? I've tested this behavior and it's exactly what happens.

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  • MySQL query problem

    - by Luke
    Ok, I have the following problem. I have two InnoDB tables: 'places' and 'events'. One place can have many events, but event can be created without entering place. In this case event's foreign key is NULL. Simplified structure of the tables looks as follows: CREATE TABLE IF NOT EXISTS `events` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(255) COLLATE utf8_bin NOT NULL, `places_id` int(9) unsigned DEFAULT NULL, PRIMARY KEY (`id`), KEY `fk_events_places` (`places_id`), ) ENGINE=InnoDB; ALTER TABLE `events` ADD CONSTRAINT `events_ibfk_1` FOREIGN KEY (`places_id`) REFERENCES `places` (`id`) ON DELETE CASCADE ON UPDATE NO ACTION; CREATE TABLE IF NOT EXISTS `places` ( `id` int(9) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(255) COLLATE utf8_bin NOT NULL, PRIMARY KEY (`id`), ) ENGINE=InnoDB; Question is, how to construct query which contains name of the event and name of the corresponding place (or no value, in case there is no place assigned?). I am able to do it with two queries, but then I am visibly separating events which have place assigned from the ones that are without place. Help really appreciated.

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  • iPhone - Using sql database - insert statement failing

    - by Satyam svv
    Hi, I'm using sqlite database in my iphone app. I've a table which has 3 integer columns. I'm using following code to write to that database table. -(BOOL)insertTestResult { NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString* documentsDirectory = [paths objectAtIndex:0]; NSString* dataBasePath = [documentsDirectory stringByAppendingPathComponent:@"test21.sqlite3"]; BOOL success = NO; sqlite3* database = 0; if(sqlite3_open([dataBasePath UTF8String], &database) == SQLITE_OK) { BOOL res = (insertResultStatement == nil) ? createStatement(insertResult, &insertResultStatement, database) : YES; if(res) { int i = 1; sqlite3_bind_int(insertResultStatement, 0, i); sqlite3_bind_int(insertResultStatement, 1, i); sqlite3_bind_int(insertResultStatement, 2, i); int err = sqlite3_step(insertResultStatement); if(SQLITE_ERROR == err) { NSAssert1(0, @"Error while inserting Result. '%s'", sqlite3_errmsg(database)); success = NO; } else { success = YES; } sqlite3_finalize(insertResultStatement); insertResultStatement = nil; } } sqlite3_close(database); return success;} The command sqlite3_step is always giving err as 19. I'm not able to understand where's the issue. Tables are created using following queries: CREATE TABLE [Patient] (PID integer NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,PFirstName text NOT NULL,PLastName text,PSex text NOT NULL,PDOB text NOT NULL,PEducation text NOT NULL,PHandedness text,PType text) CREATE TABLE PatientResult(PID INTEGER,PFreeScore INTEGER NOT NULL,PForcedScore INTEGER NOT NULL,FOREIGN KEY (PID) REFERENCES Patient(PID)) I've only one entry in Patient table with PID = 1 BOOL createStatement(const char* query, sqlite3_stmt** stmt, sqlite3* database){ BOOL res = (sqlite3_prepare_v2(database, query, -1, stmt, NULL) == SQLITE_OK); if(!res) NSLog( @"Error while creating %s => '%s'", query, sqlite3_errmsg(database)); return res;}

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  • How to join multiple tables using LINQ-to-SQL?

    - by user603245
    Hi! I'm quite new to linq, so please bear with me. I'm working on a asp.net webpage and I want to add a "search function" (textbox where user inputs name or surname or both or just parts of it and gets back all related information). I have two tables ("Person" and "Application") and I want to display some columns from Person (name and surname) and some from Application (score, position,...). I know how I could do it using sql, but I want to learn more about linq and thus I want to do it using linq. For now I got two main ideas: 1.) var person = dataContext.GetTable<Person>(); var application = dataContext.GetTable<Application>(); var p1 = from p in Person where(p.Name.Contains(tokens[0]) || p.Surname.Contains(tokens[1])) select new {Id = p.Id, Name = p.Name, Surname = p.Surname}; //or maybe without this line //I don't know how to do the following properly var result = from a in Application where a.FK_Application.Equals(index) //just to get the "right" type of application //this is not right, but I don't know how to do it better join p1 on p1.Id == a.FK_Person 2.) The other idea is just to go through "Application" and instead of "join p1 ..." to use var result = from a in Application where a.FK_Application.Equals(index) //just to get the "right" type of application join p from Person on p.Id == a.FK_Person where p.Name.Contains(tokens[0]) || p.Surname.Contains(tokens[1]) I think that first idea is better for queries without the first "where" condition, which I also intended to use. Regardless of what is better (faster), I still don't know how to do it using linq. Also in the end I wanted to display / select just some parts (columns) of the result (joined tables + filtering conditions). I really want to know how to do such things using linq as I'll be dealing also with some similar problems with local data, where I can use only linq. Could somebody please explain me how to do it, I spent days trying to figure it out and searching on the internet for answers. Thank you for your time.

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  • How to set buffer size in client-server app using sockets?

    - by nelly
    First of all i am new to networking so i may say dumb thing in here. Considering a client-server application using sockets(.net with c# if that matters). The client sends some data, the server process it and sends back a string. The client sends some other data, the serve process it, queries the db and sends back several hundreds of items from the database The client sends some other type of data and the server notifies some other clients . My question is how to set the buffer size correctly for reading/writing operation. Should i do something like this: byte[] buff = new byte[client.ReceiveBufferSize] ? I am thinking of something like this: Client sends data to the server(and the server will follow the same pattern) byte[] bytesToSend=new byte[2048] //2048 to be standard for any command send by the client bytes 0..1 ->command type bytes 1..2047 ->command parameters byte[] bytesToReceive=new byte[8]/byte[64]/byte[8192] //switch(command type) But..what is happening when a client is notified by the server without sending data? What is the correct way to accomplish what i am trying to do? Thanks for reading.

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  • [nHibernate] casting string to bool using nHibernate Criteria

    - by code-zoop
    I have an nHibernate query using Criteria, and I am trying to cast a string to bool in the query itself. I have done the same with casting a string to int, and that works well (the "DataField" property is "1" as a string): var result = Session .CreateCriteria<Car>() .Add(Restrictions.Eq((Projections.Cast(NHibernateUtil.Int32, Projections.Property("DataField"), 1)) .List<Car>(); tx.Commit(); But I am trying to do the same with bool, but I do not get the expected result: var result = Session .CreateCriteria<Car>() .Add(Restrictions.Eq((Projections.Cast(NHibernateUtil.bool, Projections.Property("DataField"), true)) .List<Car>(); tx.Commit(); "DataField" is the string "True", but the result in an empty list, where it should contain 100 elements with the "DataField" property string set to "True". I have tried with the string "true", and "1", but the result is still an empty List. [EDIT] As Commented below, I could check for the string "True" or "False", but I would say this is a more general question than just for the Boolean. Note that the idea is to have some sort of key value representation of the data, where the value can be different data types. I need the value table to contain all data, so storing the data as string seems like the cleanest solution! I have been able to use the method above to store both int and double as string, and to the cast in the query, but I have not succeeded using the same method for DateDime and Boolean. And for DateTime it is crucial to have the actual DateTime object. How can I make the cast from string to bool, and string to DateTime work in the queries? Thanks

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  • Statistical analysis on large data set to be published on the web

    - by dassouki
    I have a non-computer related data logger, that collects data from the field. This data is stored as text files, and I manually lump the files together and organize them. The current format is through a csv file per year per logger. Each file is around 4,000,000 lines x 7 loggers x 5 years = a lot of data. some of the data is organized as bins item_type, item_class, item_dimension_class, and other data is more unique, such as item_weight, item_color, date_collected, and so on ... Currently, I do statistical analysis on the data using a python/numpy/matplotlib program I wrote. It works fine, but the problem is, I'm the only one who can use it, since it and the data live on my computer. I'd like to publish the data on the web using a postgres db; however, I need to find or implement a statistical tool that'll take a large postgres table, and return statistical results within an adequate time frame. I'm not familiar with python for the web; however, I'm proficient with PHP on the web side, and python on the offline side. users should be allowed to create their own histograms, data analysis. For example, a user can search for all items that are blue shipped between week x and week y, while another user can search for sort the weight distribution of all items by hour for all year long. I was thinking of creating and indexing my own statistical tools, or automate the process somehow to emulate most queries. This seemed inefficient. I'm looking forward to hearing your ideas Thanks

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  • Tricky SQL query - need to get time frames

    - by Andrew
    I am stumbled upon a problem, when I need a query which will produce a list of speeding time frames. Here is the data example [idgps_unit_location] [dt] [idgps_unit] [lat] [long] [speed_kmh] 26 10/18/2012 18:53 2 47 56 30 27 10/18/2012 18:53 2 49 58 31 28 10/18/2012 18:53 2 28 37 15 29 10/18/2012 18:54 2 56 65 33 30 10/18/2012 18:54 2 152 161 73 31 10/18/2012 18:55 2 134 143 64 32 10/18/2012 18:56 2 22 31 12 36 10/18/2012 18:59 2 98 107 47 37 10/18/2012 18:59 2 122 131 58 38 10/18/2012 18:59 2 91 100 44 39 10/18/2012 19:00 2 190 199 98 40 10/18/2012 19:01 2 194 203 101 41 10/18/2012 19:02 2 182 191 91 42 10/18/2012 19:03 2 162 171 78 43 10/18/2012 19:03 2 174 183 83 44 10/18/2012 19:04 2 170 179 81 45 10/18/2012 19:05 2 189 198 97 46 10/18/2012 19:06 2 20 29 10 47 10/18/2012 19:07 2 158 167 76 48 10/18/2012 19:08 2 135 144 64 49 10/18/2012 19:08 2 166 175 79 50 10/18/2012 19:09 2 9 18 5 51 10/18/2012 19:09 2 101 110 48 52 10/18/2012 19:09 2 10 19 7 53 10/18/2012 19:10 2 32 41 20 54 10/18/2012 19:10 1 54 63 85 55 10/19/2012 19:11 2 55 64 50 I need a query that would convert this table into the following report that shows frames of time when speed was 80: [idgps_unit] [dt_start] [lat_start] [long_start] [speed_start] [dt_end] [lat_end] [long_end] [speed_end] [speed_average] 2 10/18/2012 19:00 190 199 98 10/18/2012 19:02 182 191 91 96.66666667 2 10/18/2012 19:03 174 183 83 10/18/2012 19:05 189 198 97 87 1 10/18/2012 19:10 54 63 85 10/18/2012 19:10 54 63 85 85 Now, what have I tried? I tried putting this into separate tables, queries and do some joins... Nothing works and I am very frustrated... I am not even sure if this could be done via the query. Asking for the expert help!

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  • PL-SQL - Two statements with begin and end, run fine seperately but not together?

    - by Twiss
    Hi all, Just wondering if anyone can help with this, I have two PLSQL statements for altering tables (adding extra fields) and they are as follows: -- Make GC_NAB field for Next Action By Dropdown begin if 'VARCHAR2' = 'NUMBER' and length('VARCHAR2')>0 and length('')>0 then execute immediate 'alter table "SERVICEMAIL6"."ETD_GUESTCARE" add(GC_NAB VARCHAR2(10, ))'; elsif ('VARCHAR2' = 'NUMBER' and length('VARCHAR2')>0 and length('')=0) or 'VARCHAR2' = 'VARCHAR2' then execute immediate 'alter table "SERVICEMAIL6"."ETD_GUESTCARE" add(GC_NAB VARCHAR2(10))'; else execute immediate 'alter table "SERVICEMAIL6"."ETD_GUESTCARE" add(GC_NAB VARCHAR2)'; end if; commit; end; -- Make GC_NABID field for Next Action By Dropdown begin if 'NUMBER' = 'NUMBER' and length('NUMBER')>0 and length('')>0 then execute immediate 'alter table "SERVICEMAIL6"."ETD_GUESTCARE" add(GC_NABID NUMBER(, ))'; elsif ('NUMBER' = 'NUMBER' and length('NUMBER')>0 and length('')=0) or 'NUMBER' = 'VARCHAR2' then execute immediate 'alter table "SERVICEMAIL6"."ETD_GUESTCARE" add(GC_NABID NUMBER())'; else execute immediate 'alter table "SERVICEMAIL6"."ETD_GUESTCARE" add(GC_NABID NUMBER)'; end if; commit; end; When I run these two queries seperately, no problems. However, when run together as shown above, Oracle gives me an error when it starts the second statement: Error report: ORA-06550: line 15, column 1: PLS-00103: Encountered the symbol "BEGIN" 06550. 00000 - "line %s, column %s:\n%s" *Cause: Usually a PL/SQL compilation error. *Action: I'm assuming that this means the first statement is not terminated properly... is there anything I should put inbetween the statements to make it work properly? Thanks in advance everyone!

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  • How can I make hundreds of simultaneously running processes communicate with a database through one

    - by Olfan
    Long speech short: How can I make hundreds of simultaneously running processes communicate with a database through one or few permanent sessions? The whole story: I once built a number crunching engine that handles vast amounts of large data files by forking off one child after another giving each a small number of files to work on. File locking, progress monitoring and result propagation happen in an Oracle database which all (sub-)processes access at various times using an application-specific module which encapsulates DBI. This worked well at first, but now with higher volumes of input data, the number of database sessions (one per child, and they can be very short-lived) constantly being opened and closed is becoming an issue. I now want to centralise database access so that there are only one or few fixed database sessions which handle all database access for all the (sub-)processes. The presence of the database abstraction module should make the changes easy because the function calls in the worker instances can stay the same. My problem is that I cannot think of a suitable way to enhance said module in order to establish communication between all the processes and the database connector(s). I thought of message queueing, but couldn't come up with a way of connecting a large herd of requestors with one or few database connectors in a way so that bidirectional communication is possible (for collecting the query result). An asynchronous approach could help here in that all requests are written to the same queue and the database connector servicing the request will "call back" to submit the result. But my mind fails me in generating an image clear enough so that I can paint into code. Threading instead of forking might have given me an easier start, but this would now require massive changes to the code base that I'm not prepared to do to a live system. The more I think of it, the more the base idea looks like a pre-forked web server to me only that it doesn't serve web pages but database queries. Any ideas on what to dig into, and where? Sample (pseudo) code to inspire me, links to possibly related articles, ready solutions on CPAN maybe?

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  • Working with PHP and MySQL - need a good and secure design with OO design

    - by Andrew
    I am new to PHP- first time developer. I am working on my web application and it is nearly done; nevertheless, most of my sql was done directly via code using direct mysql requests. This is the way I approached it: In classes_db.php I declared the db settings and created methods that I use to open and close DB connections. I declare those objects on my regular pages: class classes_db { public $dbserver = 'server; public $dbusername = 'user'; public $dbpassword = 'pass'; public $dbname = 'db'; function openDb() { $dbhandle = mysql_connect($this->dbserver, $this->dbusername, $this->dbpassword); if (!$dbhandle) { die('Could not connect: ' . mysql_error()); } $selected = mysql_select_db($this->dbname, $dbhandle) or die("Could not select the database"); return $dbhandle; } function closeDb($con) { mysql_close($con); } } On my regular page, I do this: <?php require 'classes_db.php'; session_start(); //create instance of the DB class $db = new classes_db(); //get dbhandle $dbhandle = $db->openDb(); //process query $result = mysql_query("update user set username = '" . $usernameFromForm . "' where iduser= " . $_SESSION['user']->iduser); //close the connection if (isset($dbhandle)) { $db->closeDb($dbhandle); } ?> My questions is: how to do it right and make it OO and secure? I know that I need incorporate prepared queries- how to do it the best way? Please provide some code

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  • Advice on Minimizing Stored Procedure Parameters

    - by RPM1984
    Hi Guys, I have an ASP.NET MVC Web Application that interacts with a SQL Server 2008 database via Entity Framework 4.0. On a particular page, i call a stored procedure in order to pull back some results based on selections on the UI. Now, the UI has around 20 different input selections, ranging from a textbox, dropdown list, checkboxes, etc. Each of those inputs are "grouped" into logical sections. Example: Search box : "Foo" Checkbox A1: ticked, Checkbox A2: unticked Dropdown A: option 3 selected Checkbox B1: ticked, Checkbox B2: ticked, Checkbox B3: unticked So i need to call the SPROC like this: exec SearchPage_FindResults @SearchQuery = 'Foo', @IncludeA1 = 1, @IncludeA2 = 0, @DropDownSelection = 3, @IncludeB1 = 1, @IncludeB2 = 1, @IncludeB3 = 0 The UI is not too important to this question - just wanted to give some perspective. Essentially, i'm pulling back results for a search query, filtering these results based on a bunch of (optional) selections a user can filter on. Now, My questions/queries: What's the best way to pass these parameters to the stored procedure? Are there any tricks/new ways (e.g SQL Server 2008) to do this? Special "table" parameters/arrays - can we pass through User-Defined-Types? Keep in mind im using Entity Framework 4.0 - but could always use classic ADO.NET for this if required. What about XML? What are the serialization/de-serialization costs here? Is it worth it? How about a parameter for each logical section? Comma-seperated perhaps? Just thinking out loud. This page is particulary important from a user point of view, and needs to perform really well. The stored procedure is already heavy in logic, so i want to minimize the performance implications - so keep that in mind. With that said - what is the best approach here?

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  • All connections in pool are in use

    - by veljkoz
    We currently have a little situation on our hands - it seems that someone, somewhere forgot to close the connection in code. Result is that the pool of connections is relatively quickly exhausted. As a temporary patch we added Max Pool Size = 500; to our connection string on web service, and recycle pool when all connections are spent, until we figure this out. So far we have done this: SELECT SPId FROM MASTER..SysProcesses WHERE DBId = DB_ID('MyDb') and last_batch < DATEADD(MINUTE, -15, GETDATE()) to get SPID's that aren't used for 15 minutes. We're now trying to get the query that was executed last using that SPID with: DBCC INPUTBUFFER(61) but the queries displayed are various, meaning either something on base level regarding connection manipulation was broken, or our deduction is erroneous... Is there an error in our thinking here? Does the DBCC / sysprocesses give results we're expecting or is there some side-effect catch? (for example, connections in pool influence?) (please, stick to what we could find out using SQL since the guys that did the code are many and not all present right now)

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  • entity framework navigation property further filter without loading into memory

    - by cellik
    Hi, I've two entities with 1 to N relation in between. Let's say Books and Pages. Book has a navigation property as Pages. Book has BookId as an identifier and Page has an auto generated id and a scalar property named PageNo. LazyLoading is set to true. I've generated this using VS2010 & .net 4.0 and created a database from that. In the partial class of Book, I need a GetPage function like below public Page GetPage(int PageNumber) { //checking whether it exist etc are not included for simplicity return Pages.Where(p=>p.PageNo==PageNumber).First(); } This works. However, since Pages property in the Book is an EntityCollection it has to load all Pages of a book in memory in order to get the one page (this slows down the app when this function is hit for the first time for a given book). i.e. Framework does not merge the queries and run them at once. It loads the Pages in memory and then uses LINQ to objects to do the second part To overcome this I've changed the code as follows public Page GetPage(int PageNumber) { MyContainer container = new MyContainer(); return container.Pages.Where(p=>p.PageNo==PageNumber && p.Book.BookId==BookId).First(); } This works considerably faster however it doesn't take into account the pages that have not been serialized to the db. So, both options has its cons. Is there any trick in the framework to overcome this situation. This must be a common scenario where you don't want all of the objects of a Navigation property loaded in memory when you don't need them.

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  • SQL Database Schema Design For Large 3 Billion Relationship Database.

    - by K-Bell
    Get your geek on. Can you solve this? I am designing a products database for SQL Server 2008 R2 Ed. (not Enterprise Ed.) that will be used to store custom product configurations for over 30,000 distinct products. The database will have up to 500 users at a time. Here is the design problem… Each Product has a collection of Parts (up to 50 parts per product). So if I have 30,000 Products and each of them can have up to 50 Parts, that’s 1.5 million distinct Product-to-Part relationships …or as an equation… 30,000 (Products) X 50 (Parts) = 1.5 million Product-to-Parts records. …and If… Each Part can have up to 2000 finish options (A finish is a paint color). NOTE: Only one finish will be selected by a user at run-time. The 2000 finish options I need to store are the allowed options for a specific part on a specific product. So if I have 1.5 million distinct product-to-part relationships/records and each of those parts can have up to 2,000 finishes that is 3 billion allowable product-to-part-to finish relationships/records …or as an equation… 1.5 million (Parts) x 2,000 (Finishes) = 3 Billion Product-to-Part-to-Finishes records. How can I design this database so that I can execute fast and efficient queries for a specific product and return its list of Parts and all the allowable Finishes for each part without 3 Billion Product-to-Part-to-Finish records? Read time is more important then write time. Please post your thoughts/suggestions if you have experience with large databases. Thanks!

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