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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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  • What different terms mean the same thing (or don't, but people think they do)?

    - by Matthew Jones
    One of the pitfalls I run into on a daily basis is customers saying one thing while meaning another. Usually, this is just due to a miscommunication somewhere, but occasionally they are, in fact, saying the same thing I am just using a different term. For example, one of my customers the other day mentioned a feature he called, "find as you type." Being a little confused, I asked him what he meant, and he described the feature in Google where, once you start typing a search query, Google suggests other, popular queries that match the letters you have typed. Click! He meant AutoComplete! He was not wrong, it is just that I had never heard that term before. In the spirit of reducing confusion, what terms can you think of that are different but mean, essentially, the same thing? Also, what terms do people think mean the same thing, but don't. Please differentiate between the two. Please only one set of terms per answer, so we can vote on the best ones.

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  • Scalable Full Text Search With Per User Result Ordering

    - by jeremy
    What options exist for creating a scalable, full text search with results that need to be sorted on a per user basis? This is for PHP/MySQL (Symfony/Doctrine as well, if relevant). In our case, we have a database of workouts that have been performed by users. The workouts that the user has done before should appear at the top of the results. The more frequently they've done the workout, the higher it should appear in search matches. If it helps, you can assume we know the number of times a user has done a workout in advance. Possible Solutions Sphinx - Use Sphinx to implement full text search, do all the querying and sorting in MySQL. This seems promising (and there's a Symfony Plugin!) but I don't know much about it. Lucene - Use Lucene to perform full text search and put the users' completions into the query. As is suggested in this Stack Overflow thread. Alternatively, use Lucene to retrieve the results, then reorder them in PHP. However, both solutions seem clunky and potentially unscalable as a user may have completed hundreds of workouts. Mysql - No native full text support (InnoDB), so we'd have use LIKE or REGEX, which isn't scalable.

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  • Use a foreign key mapping to get data from the other table using Python and SQLAlchemy.

    - by Az
    Hmm, the title was harder to formulate than I thought. Basically, I've got these simple classes mapped to tables, using SQLAlchemy. I know they're missing a few items but those aren't essential for highlighting the problem. class Customer(object): def __init__(self, uid, name, email): self.uid = uid self.name = name self.email = email def __repr__(self): return str(self) def __str__(self): return "Cust: %s, Name: %s (Email: %s)" %(self.uid, self.name, self.email) The above is basically a simple customer with an id, name and an email address. class Order(object): def __init__(self, item_id, item_name, customer): self.item_id = item_id self.item_name = item_name self.customer = None def __repr__(self): return str(self) def __str__(self): return "Item ID %s: %s, has been ordered by customer no. %s" %(self.item_id, self.item_name, self.customer) This is the Orders class that just holds the order information: an id, a name and a reference to a customer. It's initialised to None to indicate that this item doesn't have a customer yet. The code's job will assign the item a customer. The following code maps these classes to respective database tables. # SQLAlchemy database transmutation engine = create_engine('sqlite:///:memory:', echo=False) metadata = MetaData() customers_table = Table('customers', metadata, Column('uid', Integer, primary_key=True), Column('name', String), Column('email', String) ) orders_table = Table('orders', metadata, Column('item_id', Integer, primary_key=True), Column('item_name', String), Column('customer', Integer, ForeignKey('customers.uid')) ) metadata.create_all(engine) mapper(Customer, customers_table) mapper(Orders, orders_table) Now if I do something like: for order in session.query(Order): print order I can get a list of orders in this form: Item ID 1001: MX4000 Laser Mouse, has been ordered by customer no. 12 What I want to do is find out customer 12's name and email address (which is why I used the ForeignKey into the Customer table). How would I go about it?

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  • PROLOG - DCG parsing

    - by user2895589
    Hello I am new Prolog and DGC.I want to write a DCG to parse time expressions like 10.20 am or 12 oclock. how can I check 10.20 am is valid expression or not for Olcock I wrote some code. oclock --> digit1,phrase1. digit1 --> [T],{digit1(T)}. digit1(1). digit1(2). digit1(3). digit1(4). digit1(5). digit1(6). digit1(7). digit1(8). digit1(9). digit1(10). digit1(11). digit1(12). phrase1 --> [P],{phrase1(P)}. phrase1(Oclock). i ma checking by query oclock([1,oclock],[]). can someone help me on this.

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  • SELECT Statement without duplicate rows on the multiple join tables

    - by theBo
    I have 4 tables built with JOINS and I would like to SELECT DISTINCT rows on the setsTbl.s_id so they always show regardless if there's relational data against them or not!. This is what I have at present which displays the data but doesn't display all of but not the entire distinct row! SELECT setsTbl.s_id, setsTbl.setName, userProfilesTbl.no + ' ' + userProfilesTbl.surname AS Name, trainingTbl.t_date, userAssessmentTbl.o_id FROM userProfilesTbl LEFT OUTER JOIN userAssessmentTbl ON userProfilesTbl.UserId = userAssessmentTbl.UserId FULL OUTER JOIN trainingTbl ON userAssessmentTbl.tt_id = trainingTbl.tt_id RIGHT OUTER JOIN setsTbl ON trainingTbl.s_id = setsTbl.s_id WHERE (userProfilesTbl.st_id=@st_id AND userProfilesTbl.sh_id=@sh_id) AND (DATEPART(yyyy,t_date) = @y_date ) OR (userAssessmentTbl.o_id IS NULL) ORDER BY setName ASC, t_date ASC With this statement I get some of the rows (the ones with data against them) but as stated the s_id field does not return distinct. This following inner select statement works in part when used in SQL Query analyzer and returns pretty much the data i require s_id setName Name o_id ----- ----- ----- ------ 1 100 Barnes 2 2 100 Beardsley 3 3 101 Aldridge 1 4 102 Molby 2 5 102 Whelan 3 but not when used outside of that environment. select * from ( SELECT userProfilesTbl.serviceNo + ' ' + userProfilesTbl.surname AS Name, userProfilesTbl.st_id, userProfilesTbl.sh_id, userAssessmentTbl.o_id, setsTbl.s_id, setsTbl.setName, row_number() over ( partition by setsTbl.s_id order by setsTbl.s_id ) r FROM userProfilesTbl LEFT OUTER JOIN userAssessmentTbl ON userProfilesTbl.UserId = userAssessmentTbl.UserId FULL OUTER JOIN trainingTbl ON userAssessmentTbl.tt_id = trainingTbl.tt_id RIGHT OUTER JOIN setsTbl ON trainingTbl.s_id = setsTbl.s_id ) x where x.r = 1 Not receiving any errors just not displaying the data?

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  • Append data to same text file

    - by Manu
    SimpleDateFormat formatter = new SimpleDateFormat("ddMMyyyy_HHmmSS"); String strCurrDate = formatter.format(new java.util.Date()); String strfileNm = "Customer_" + strCurrDate + ".txt"; String strFileGenLoc = strFileLocation + "/" + strfileNm; String Query1="select '0'||to_char(sysdate,'YYYYMMDD')||'123456789' class_code from dual"; String Query2="select '0'||to_char(sysdate,'YYYYMMDD')||'123456789' class_code from dual"; try { Statement stmt = null; ResultSet rs = null; Statement stmt1 = null; ResultSet rs1 = null; stmt = conn.createStatement(); stmt1 = conn.createStatement(); rs = stmt.executeQuery(Query1); rs1 = stmt1.executeQuery(Query2); File f = new File(strFileGenLoc); OutputStream os = (OutputStream)new FileOutputStream(f,true); String encoding = "UTF8"; OutputStreamWriter osw = new OutputStreamWriter(os, encoding); BufferedWriter bw = new BufferedWriter(osw); while (rs.next() ) { bw.write(rs.getString(1)==null? "":rs.getString(1)); bw.write(" "); } bw.flush(); bw.close(); } catch (Exception e) { System.out.println( "Exception occured while getting resultset by the query"); e.printStackTrace(); } finally { try { if (conn != null) { System.out.println("Closing the connection" + conn); conn.close(); } } catch (SQLException e) { System.out.println( "Exception occured while closing the connection"); e.printStackTrace(); } } return objArrayListValue; } The above code is working fine. it writes the content of "rs" resultset data in text file Now what i want is ,i need to append the the content in "rs2" resultset to the "same text file"(ie . i need to append "rs2" content with "rs" content in the same text file)..

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  • (Rails) Creating multi-dimensional hashes/arrays from a data set...?

    - by humble_coder
    Hi All, I'm having a bit of an issue wrapping my head around something. I'm currently using a hacked version of Gruff in order to accommodate "Scatter Plots". That said, the data is entered in the form of: g.data("Person1",[12,32,34,55,23],[323,43,23,43,22]) ...where the first item is the ENTITY, the second item is X-COORDs, and the third item is Y-COORDs. I currently have a recordset of items from a table with the columns: POINT, VALUE, TIMESTAMP. Due to the "complex" calculations involved I must grab everything using a single query or risk way too much DB activity. That said, I have a list of items for which I need to dynamically collect all data from the recordset into a hash (or array of arrays) for the creation of the data items. I was thinking something like the following: @h={} e = Events.find_by_sql(my_query) e.each do |event| @h["#{event.Point}"][x] = event.timestamp @h["#{event.Point}"][y] = event.value end Obviously that's not the correct syntax, but that's where my brain is going. Could someone clean this up for me or suggest a more appropriate mechanism by which to accomplish this? Basically the main goal is to keep data for each pointname grouped (but remember the recordset has them all). Much appreciated. EDIT 1 g = Gruff::Scatter.new("600x350") g.title = self.name e = Event.find_by_sql(@sql) h ={} e.each do |event| h[event.Point.to_s] ||= {} h[event.Point.to_s].merge!({event.Timestamp.to_i,event.Value}) end h.each do |p| logger.info p[1].values.inspect g.data(p[0],p[1].keys,p[1].values) end g.write(@chart_file)

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  • unexpected behaviour of object stored in web service Session

    - by draconis
    Hi. I'm using Session variables inside a web service to maintain state between successive method calls by an external application called QBWC. I set this up by decorating my web service methods with this attribute: [WebMethod(EnableSession = true)] I'm using the Session variable to store an instance of a custom object called QueueManager. The QueueManager has a property called ChangeQueue which looks like this: [Serializable] public class QueueManager { ... public Queue<QBChange> ChangeQueue { get; set; } ... where QBChange is a custom business object belonging to my web service. Now, every time I get a call to a method in my web service, I use this code to retrieve my QueueManager object and access my queue: QueueManager qm = (QueueManager)Session[ticket]; then I remove an object from the queue, using qm.dequeue() and then I save the modified query manager object (modified because it contains one less object in the queue) back to the Session variable, like so: Session[ticket] = qm; ready for the next web service method call using the same ticket. Now here's the thing: if I comment out this last line //Session[ticket] = qm; , then the web service behaves exactly the same way, reducing the size of the queue between method calls. Now why is that? The web service seems to be updating a class contained in serialized form in a Session variable without being asked to. Why would it do that? When I deserialize my Queuemanager object, does the qm variable hold a reference to the serialized object inside the Session[ticket] variable?? This seems very unlikely.

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  • Implementing Unowned relationship Google App Engine

    - by nwallman
    My question is more of a best practices question on how to implement unowned relationships with Google App Engine. I am using JDO to do my persistence and like recommended in the google docs I'm persisting my list of unowned relationships like so: @PersistenceCapable(identityType = IdentityType.APPLICATION) public class User implements Serializable, UserDetails { ... @Persistent private List<Key> groups; ... } Now I came across my predicament when I went to query that list of objects using they Key object. So when I get my list of group keys in order to actually return a list of Group objects I have to do a look up on that key to get the object. My question is what is the recommended way of doing a unowned look up on a model object? Should I have an instance of the PersistanceManagerFactory on my Model object so I can do a lookup? Should I have an instance of my GroupDAO object on my Model object so I can do a look up? Should I have a Utility to do this type of lookup? I'm new to this so I just want to know which is the best way to do this. Thanks.

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  • Contacts & Autocomplete

    - by Vince
    First post. I'm new to android and programming in general. What I'm attempting to is to have an autocomplete text box pop up with auto complete names from the contact list. IE, if they type in "john" it will say "John Smith" or any john in their contacts. The code is basic, I pulled it from a few tutorials. private void autoCompleteBox() { ContentResolver cr = getContentResolver(); Uri contacts = Uri.parse("content://contacts/people"); Cursor managedCursor1 = cr.query(contacts, null, null, null, null); if (managedCursor1.moveToFirst()) { String contactname; String cphoneNumber; int nameColumn = managedCursor1.getColumnIndex("name"); int phoneColumn = managedCursor1.getColumnIndex("number"); Log.d("int Name", Integer.toString(nameColumn)); Log.d("int Number", Integer.toString(phoneColumn)); do { // Get the field values contactname = managedCursor1.getString(nameColumn); cphoneNumber = managedCursor1.getString(phoneColumn); if ((contactname != " " || contactname != null) && (cphoneNumber != " " || cphoneNumber != null)) { c_Name.add(contactname); c_Number.add(cphoneNumber); Toast.makeText(this, contactname, Toast.LENGTH_SHORT) .show(); } } while (managedCursor1.moveToNext()); } name_Val = (String[]) c_Name.toArray(new String[c_Name.size()]); phone_Val = (String[]) c_Number.toArray(new String[c_Name.size()]); ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, name_Val); personName.setAdapter(adapter); } personName is my autocompletetextbox. So it actually works when I use it in the emulator (4.2) with manually entered contacts through the people app, but when I use it on my device, it will not pop up with any names. I'm sure it's something ridiculous but I've tried to find the answer and I'm getting nowhere. Can't learn if I don't ask.

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  • logic before dispatcher + controller?

    - by Spoonface
    I believe for a typical MVC web application the router / dispatcher routine is used to decide which controller is loaded based primarily on the area requested in the url by the user. However, in addition to checking the url query string, I also like to use the dispatcher to check whether the user is currently logged in or not to decide which controller is loaded. For example if they are logged in and request the login page, the dispatcher would load their account instead. But is this a fairly non-standard design? Would it violate MVC in any way? I only ask as the examples I've read through this weekend have had no major calculations performed before the dispatcher routine, and commonly check whether the user is logged in or not per controller, and then redirect where necessary. But to me it seems odd to redirect a logged in user from the login area to account area if you could just load the account controller in the first place? I hope I've explained my consternation well enough, but could anyone offer some details on how they handle logged in users, and similar session data?

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  • Indexing/Performance strategies for vast amount of the same value

    - by DrColossos
    Base information: This is in context to the indexing process of OpenStreetMap data. To simplify the question: the core information is divided into 3 main types with value "W", "R", "N" (VARCHAR(1)). The table has somewhere around ~75M rows, all columns with "W" make up ~42M rows. Existing indexes are not relevant to this question. Now the question itself: The indexing of the data is done via an procedure. Inside this procedure, there are some loops that do the following: [...] SELECT * FROM table WHERE the_key = "W"; [...] The results get looped again and the above query itself is also in a loop. This takes a lot of time and slows down the process massivly. An indexon the_key is obviously useless since all the values that the index might use are the same ("W"). The script itself is running with a speed that is OK, only the SELECTing takes very long. Do I need to create a "special" kind of index that takes this into account and makes the SELECT quicker? If so, which one? need to tune some of the server parameters (they are already tuned and the result that they deliver seem to be good. If needed, I can post them)? have to live with the speed and simply get more hardware to gain more power (Tim Taylor grunt grunt)? Any alternatives to the above points (except rewriting it or not using it)?

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  • Silverlight 4 webclient authentication - anyone have this working yet?

    - by Toran Billups
    So one of the best parts about the new Silverlight 4 beta is that they finally implemented the big missing feature of the networking stack - Network Credentials! In the below I have a working request setup, but for some reason I get a "security error" when the request comes back - is this because twitter.com rejected my api call or something that I'm missing in code? It might be good to point out that when I watch this code execute via fiddler it shows that the xml file for cross domain is pulled down successfully, but that is the last request shown by fiddler ... public void RequestTimelineFromTwitterAPI() { WebRequest.RegisterPrefix("https://", System.Net.Browser.WebRequestCreator.ClientHttp); WebClient myService = new WebClient(); myService.AllowReadStreamBuffering = true; myService.UseDefaultCredentials = false; myService.Credentials = new NetworkCredential("username", "password"); myService.UseDefaultCredentials = false; myService.OpenReadCompleted += new OpenReadCompletedEventHandler(TimelineRequestCompleted); myService.OpenReadAsync(new Uri("https://twitter.com/statuses/friends_timeline.xml")); } public void TimelineRequestCompleted(object sender, System.Net.OpenReadCompletedEventArgs e) { //anytime I query for e.Result I get a security error }

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  • Why do I get null objects in a many-to-many bag?

    - by Jim Geurts
    I have a bag defined for a many-to-many list: <class name="Author" table="Authors"> <id name="Id" column="AuthorId"> <generator class="identity" /> </id> <property name="Name" /> <bag name="Books" table="Author_Book_Map" where="IsDeleted=0" fetch="join"> <key column="AuthorId" /> <many-to-many class="Book" column="BookId" where="IsDeleted=0" /> </bag> </class> If I return all author objects using something like the following, I will get what initially appeared to be duplicate Author records: Session.Query<Author>().List<Author>() The extra author objects are created when an author is mapped to Book objects that have IsDeleted = 1 and IsDeleted = 0. Rather than creating one Author object with an enumerable that contains only the books with IsDeleted = 0, it will create two author objects. The first author object has a Books enumerable that contains books with IsDeleted = 0. The second author object will contain an enumerable of null book objects. Similarly, if an object only has one book map, and that map points to a book with IsDeleted = 1, then an author object is returned with a Books collection having one null object. I'm thinking part of the problem stems from the map table objects linking to rows that satisfy the where condition on the bag object but do not meet the many-to-many where condition. This is happening with NHibernate version 3.0.0.4980. Is this a configuration issue or something else?

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  • reporting tool/viewer for large datasets

    - by FrustratedWithFormsDesigner
    I have a data processing system that generates very large reports on the data it processes. By "large" I mean that a "small" execution of this system produces about 30 MB of reporting data when dumped into a CSV file and a large dataset is about 130-150 MB (I'm sure someone out there has a bigger idea of "large" but that's not the point... ;) Excel has the ideal interface for the report consumers in the form of its Data Lists: users can filter and segment the data on-the-fly to see the specific details that they are interested in - they can also add notes and markup to the reports, create charts, graphs, etc... They know how to do all this and it's much easier to let them do it if we just give them the data. Excel was great for the small test datasets, but it cannot handle these large ones. Does anyone know of a tool that can provide a similar interface as Excel data lists, but that can handle much larger files? The next tool I tried was MS Access, and found that the Access file bloats hugely (30 MB input file leads to about 70 MB Access file, and when I open the file, run a report and close it the file's at 120-150 MB!), the import process is slow and very manual (currently, the CSV files are created by the same plsql script that runs the main process so there's next to no intervention on my part). I also tried an Access database with linked tables to the database tables that store the report data and that was many times slower (for some reason, sqlplus could query and generate the report file in a minute or soe while Access would take anywhere from 2-5 minutes for the same data) (If it helps, the data processing system is written in PL/SQL and runs on Oracle 10g.)

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  • Is encrypting session id (or other authenticate value) in cookie useful at all?

    - by Ji
    In web development, when session state is enabled, a session id is stored in cookie(in cookieless mode, query string will be used instead). In asp.net, the session id is encrypted automatically. There are plenty of topics on the internet regarding how you should encrypt your cookie, including session id. I can understand why you want to encrypt private info such as DOB, but any private info should not be stored in cookie at first place. So for other cookie values such as session id, what is the purpose encryption? Does it add security at all? no matter how you secure it, it will be sent back to server for decryption. Be be more specific, For authentication purpose, turn off session, i don't want to deal with session time out any more store some sort of id value in the cookie, on the server side, check if the id value exists and matches, if it is, authenticate user. let the cookie value expire when browser session is ended, this way. vs Asp.net form authentication mechanism (it relies on session or session id, i think) does latter one offer better security?

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  • Round date to 10 minutes interval

    - by Peter Lang
    I have a DATE column that I want to round to the next-lower 10 minute interval in a query (see example below). I managed to do it by truncating the seconds and then subtracting the last digit of minutes. WITH test_data AS ( SELECT TO_DATE('2010-01-01 10:00:00', 'YYYY-MM-DD HH24:MI:SS') d FROM dual UNION SELECT TO_DATE('2010-01-01 10:05:00', 'YYYY-MM-DD HH24:MI:SS') d FROM dual UNION SELECT TO_DATE('2010-01-01 10:09:59', 'YYYY-MM-DD HH24:MI:SS') d FROM dual UNION SELECT TO_DATE('2010-01-01 10:10:00', 'YYYY-MM-DD HH24:MI:SS') d FROM dual UNION SELECT TO_DATE('2099-01-01 10:00:33', 'YYYY-MM-DD HH24:MI:SS') d FROM dual ) -- #end of test-data SELECT d, TRUNC(d, 'MI') - MOD(TO_CHAR(d, 'MI'), 10) / (24 * 60) FROM test_data And here is the result: 01.01.2010 10:00:00    01.01.2010 10:00:00 01.01.2010 10:05:00    01.01.2010 10:00:00 01.01.2010 10:09:59    01.01.2010 10:00:00 01.01.2010 10:10:00    01.01.2010 10:10:00 01.01.2099 10:00:33    01.01.2099 10:00:00 Works as expected, but is there a better way? EDIT: I was curious about performance, so I did the following test with 500.000 rows and (not really) random dates. I am going to add the results as comments to the provided solutions. DECLARE t TIMESTAMP := SYSTIMESTAMP; BEGIN FOR i IN ( WITH test_data AS ( SELECT SYSDATE + ROWNUM / 5000 d FROM dual CONNECT BY ROWNUM <= 500000 ) SELECT TRUNC(d, 'MI') - MOD(TO_CHAR(d, 'MI'), 10) / (24 * 60) FROM test_data ) LOOP NULL; END LOOP; dbms_output.put_line( SYSTIMESTAMP - t ); END; This approach took 03.24 s.

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  • how to programatically compare permissions of login/user in sql server 2005

    - by titanium
    There's a login/user in SQL Server who is having a problem importing accounts in production server. I don't have an idea what method he is doing this. According to the one importing, this import is working fine in development server. But when he did the same import in production it is giving him errors. Below are the errors he is getting for each accounts. 2009-06-05 18:01:05.8254 ERROR [engine-1038] Task [1038:00001 - Members]: Step 1.0 [<Insert step description>]: Task.RunStep(): StoreRow has failed 2009-06-05 18:01:05.9035 ERROR [engine-1038] Task [1038:00001 - Members]: Step 1.0 [<Insert step description>]: Task.RunStep(): StoreRow exception: Exception caught while storing Data. [Microsoft][ODBC SQL Server Driver][SQL Server]'ACCOUNT1' is not a valid login or you do not have permission. Please note that 'ACCOUNT1' is not the real account name. I just changed it for security reason. Using SQL Server Management Studio (SSMS), I viewed/checked the permissions of the user/login who is performing the import from development server and production for comparison. I found no difference. My question is: Is there a way to programmatically query permissions in server and database level of a particular login/user so I can compare/contrast for any differences?

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  • Linq - reuse expression on child property

    - by user175528
    Not sure if what I am trying is possible or not, but I'd like to reuse a linq expression on an objects parent property. With the given classes: class Parent { int Id { get; set; } IList<Child> Children { get; set; } string Name { get; set; } } class Child{ int Id { get; set; } Parent Dad { get; set; } string Name { get; set; } } If i then have a helper Expression<Func<Parent,bool> ParentQuery() { Expression<Func<Parent,bool> q = p => p.Name=="foo"; } I then want to use this when querying data out for a child, along the lines of: using(var context=new Entities.Context) { var data=context.Child.Where(c => c.Name=="bar" && c.Dad.Where(ParentQuery)); } I know I can do that on child collections: using(var context=new Entities.Context) { var data=context.Parent.Where(p => p.Name=="foo" && p.Childen.Where(childQuery)); } but cant see any way to do this on a property that isnt a collection. This is just a simplified example, actually the ParentQuery will be more complex and I want to avoid having this repeated in multiple places as rather than just having 2 layers I'll have closer to 5 or 6, but all of them will need to reference the parent query to ensure security.

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  • Determining Best Table Structure for MySQL Performance

    - by Joe Majewski
    I'm working on a browser-based RPG for one of my websites, and right now I'm trying to determine the best way to organize my SQL tables for performance and maintenance. Here's my question: Does the number of columns in an SQL table affect the speed in which it can be queried? I am not a newbie when it comes to PHP or MySQL. I used to develop things with the common goal of getting them to work, but I've recently advanced to the stage where a functional program is not good enough unless it's fast and reliable. Anyways, right now I have a members table that has around 15 columns. It contains information such as the player's username, password, email, logins, page views, etcetera. It doesn't contain any information on the player's progress in the game, however. If I added columns for things such as army size, gold, turns, and whatnot, then it could easily rise to around 40 or 50 total columns. Oh, and my database structure IS normalized. Will a table with 50 columns that gets constantly queried be a bad idea? Should I split it into two tables; one for the user's general information and one for the user's game statistics? I know I could check the query time myself, but I haven't actually created the tables yet and I think I'd be better off with some professional advice on this important decision for my game. Thank you for your time! :)

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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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  • How to get <td> value in textbox

    - by Shreeuday Kasat
    I've done some code in html and in JavaScript ... My query is when I click on <td>, whatever the value associated with it, has to be displayed in the corresponding text box ... In front of <td> I've taken the textbox ... for an example I've taken 3 <td> and 3 textboxes <script type="text/javascript"> function click3(x) { x = document.getElementById("name").innerHTML var a = document.getElementById("txt"); a.value = x; } function click1(y) { y = document.getElementById("addr").innerHTML var b = document.getElementById("txt1"); b.value = y; } function click2(z) { z = document.getElementById("email").innerHTML var c = document.getElementById("txt2"); c.value = z; } </script> this is my JavaScript code , I know this is not an adequate way to deal such problem, since its giving static way to deal with this problem does anyone have a better solution for this problem ?? In JavaScript/jQuery

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  • Need help/suggestions for creating fantasy sports scoring databases and queries

    - by MGumbel
    I'm trying to create a website for my friends and I to keep track of fantasy sports scoring. So far, I've been doing the calculations and storage in Excel, which is very tedious. I'm trying to make it more simplified and automated through a SQL database that I can then wrap a web app around to enter daily stat updates. It's premised on our participation in another commercial site where we trade virtual shares of athletes, and thus acquire an "ownership percentage" in each athlete. For instance, if there are 100 shares of AROD, and I own 10 shares, then I own 10%. It then applies this to traditional baseball rotisserie scoring. So, for instance, if AROD has 1 HR today, then his adjusted HR stat would be 1.10. If he also has 2 RBI's, then his adjusted RBI stat today would be 2.20, based on (2 x 1.10)(1 to normalize the stat, and the .10 to represent the ownership percentage). All the stats for my team would then be summed each day and added to my stat history to come to an aggregated total. After that, points are allocated based on the ranking of each participant in each category at the end of the day. E.g. if there are 10 participants, and I have the highest total aggregate number of Adjusted HR's, then I get 10 pts. The points are then summed across the different stat categories to come up with a total point ranking for that day. An added difficulty is that ownership %'s can change on a daily basis. So far, in playing around with different schema, I don't know that having a separate table for each athlete's stats and each player's ownership %'s is the wisest choice. It seems to me that simply having two tables, one that contains the daily stat information for each athlete, and another that shows the ownership % of each player. My friend suggested using a start and end date for each ownership % to represent the potential daily changes in this category. I'm admittedly new to database development, so any suggestions on query code would be appreciated.

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  • How do I implement Hibernate Pagination using a cursor (so the results stay consistent, despite new

    - by hunterae
    Hey all, Is there any way to maintain a database cursor using Hibernate between web requests? Basically, I'm trying to implement pagination, but the data that is being paged is consistently changing (i.e. new records are added into the database). We are trying to set it up such that when you do your initial search (returning a maximum of 5000 results), and you page through the results, those same records always appear on the same page (i.e. we're not continuously running the query each time next and previous page buttons are clicked). The way we're currently implementing this is by merely selecting 5000 (at most) primary keys from the table we're paging, storing those keys in memory, and then just using 20 primary keys at a time to fetch their details from the database. However, we want to get away from having to store these keys in memory and would much prefer a database cursor that we just keep going back to and moving backwards and forwards over the cursor to generate pages. I tried doing this with Hibernate's ScrollableResults but found that I could not call methods like next() and previous() would cause an exception if you within a different web request / Hibernate session (no surprise there). Is there any way to reattach a ScrollableResults object to a Session, much the same way you would reattach a detached database object to make it persistent? Are there any other approaches to implement this data paging with consistent paging results without caching the primary keys?

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