Search Results

Search found 25852 results on 1035 pages for 'linq query syntax'.

Page 33/1035 | < Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >

  • Invalid syntax in this simple Python application.

    - by Sergio Boombastic
    Getting an invalid syntax when creating the template_value variable: class MainPage(webapp.RequestHandler): def get(self): blogPosts_query = BlogPost.all().order('-postDate') blogPosts = blogPosts_query.fetch(10) if users.get_current_user(): url = users.create_logout_url(self.request.uri) url_linktext = 'Logout' else: url = url = users.create_login_url(self.request.uri) url_linktext = 'Login' template_value = ( 'blogPosts': blogPosts, 'url': url, 'url_linktext': url_linktext, ) path = os.path.join(os.path.dirname(__file__), 'index.html') self.response.out.write(template.render(path, template_values)) The error fires specifically on the 'blogPosts': blogPosts line. What am I doing wrong? Thanks!

    Read the article

  • javascript syntax

    - by Michael
    var ret = [] ,xresult = document.evaluate(exp, rootEl, null, XPathResult.UNORDERED_NODE_ITERATOR_TYPE, null) ,result = xresult.iterateNext(); while (result) { ret[ret.length]= result; result = xresult.iterateNext(); } can anyone explain me what is the ret = [],..,... syntax? Initializing array?

    Read the article

  • F# constructor syntax - overiding and augmenting new

    - by Benjol
    I have a non-disposable class with Open/Close syntax that I'd like to be able to use, so I'm trying to inherit from it, and work the Open into the new and the Close into Dispose. The second part is ok, but I can't work out how to do the Open: type DisposableOpenCloseClass(openargs) = inherit OpenCloseClass() //do this.Open(openargs) <-- compiler no like interface IDisposable with member this.Dispose() = this.Close() (cf. this question which I asked a long time ago, but I can't join the dots to this one)

    Read the article

  • What is tagged structure initialization syntax?

    - by httpinterpret
    struct file_operations scull_fops = { .owner = THIS_MODULE, .llseek = scull_llseek, .read = scull_read, .write = scull_write, .ioctl = scull_ioctl, .open = scull_open, .release = scull_release, }; This declaration uses the standard C tagged structure initialization syntax. Can someone elaborate?

    Read the article

  • Syntax highlighting Abbreviations

    - by Nimbuz
    I'm using Google prettify for syntax highlighting and I'd like to modify the colors to match my website theme, but I don't understand some of the abbreviations from these: str = string atw kwd = keyword tag = tag com = comment typ = type? atn dec = declaration? lit pun = punctuation? like colons, braces? pln prettyprint

    Read the article

  • Strange ruby syntax

    - by AntonAL
    Hi, what the syntax is in Action Mailer Basics rails guide ? class UserMailer < ActionMailer::Base def welcome_email(user) recipients user.email from "My Awesome Site Notifications <[email protected]>" subject "Welcome to My Awesome Site" sent_on Time.now body {:user => user, :url => "http://example.com/login"} end end How should i understand the construction, like from "Some text for this field" Is it an assignment the value to a variable, called "from" ?

    Read the article

  • Are elements returned by Linq-to-Entities query streamed from the DB one at the time or are they retrieved all at once?

    - by carewithl
    Are elements returned by Linq-to-Entities query streamed from the database one at the time ( as they are requested ) or are they retrieved all at once: SampleContext context = new SampleContext(); // SampleContext derives from ObjectContext var search = context.Contacts; foreach (var contact in search) { Console.WriteLine(contact.ContactID); // is each Contact retrieved from the DB // only when foreach requests it? } thank you in advance

    Read the article

  • LinqToSQL _conn ? LinqToSQLConnection ?

    - by nCdy
    here is a code : using System; using Nemerle.Collections; using Nemerle.Text; //using Nemerle.Utility; using System.Linq; using Nemerle.Data.Linq; using NUnit.Framework; using System.Data.Linq; namespace LinqTestes { [TestFixture] public class Linq2SqlTests { static ReadConnectionString() : string { def currAssm = Uri(typeof(Linq2SqlTests).Assembly.CodeBase).LocalPath; def path = IO.Path.GetDirectoryName(currAssm); def connStrPath = IO.Path.Combine(path, "connectionString.txt"); def connStr = try { IO.File.ReadAllText(connStrPath, Text.Encoding.UTF8) } catch { | e is IO.FileNotFoundException => throw IO.FileNotFoundException( $"You should define connection string to NorthWind DB in: '$connStrPath'", e.FileName, e) }; connStr } _conn : LinqDataConnection = LinqDataConnection(ReadConnectionString()); and I'm making the same but what is LinqDataConnection type ? and where does it comes from ?

    Read the article

  • SQL query: Delete a entry which is not present in a join table?

    - by Mestika
    Hi, I’m going to delete all users which has no subscription but I seem to run into problems each time I try to detect the users. My schemas look like this: Users = {userid, name} Subscriptionoffering = {userid, subscriptionname} Now, what I’m going to do is to delete all users in the user table there has a count of zero in the subscriptionoffering table. Or said in other words: All users which userid is not present in the subscriptionoffering table. I’ve tried with different queries but with no result. I’ve tried to say where user.userid <> subscriptionoffering.userid, but that doesn’t seem to work. Do anyone know how to create the correct query? Thanks Mestika

    Read the article

  • why doesnt' nhibernate support this syntax ??

    - by ooo
    i have the following query and its failing in Nhibernate 3 LINQ witha a "Non supported" exception. My DB tables are: VacationRequest (id, personId) VacationRequestDate (id, vacationRequestId) Person (id, FirstName, LastName) My Entities are: VacationRequest (Person, IList) VacationRequestDate (VacationRequest, Date) Here is the query that is getting a "Non supported" Exception Session.Query<VacationRequestDate>().Where(r => people.Contains(r.VacationRequest.Person, new PersonComparer())).Fetch(r=>r.VacationRequest).ToList(); is there a better way to write this that would be supported in Nhibernate? fyi . .the PersonComparer just compared person.Id

    Read the article

  • Is there anything else I can do to optimize this MySQL query?

    - by Legend
    I have two tables, Table A with 700,000 entries and Table B with 600,000 entries. The structure is as follows: Table A: +-----------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-----------+---------------------+------+-----+---------+----------------+ | id | bigint(20) unsigned | NO | PRI | NULL | auto_increment | | number | bigint(20) unsigned | YES | | NULL | | +-----------+---------------------+------+-----+---------+----------------+ Table B: +-------------+---------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+---------------------+------+-----+---------+----------------+ | id | bigint(20) unsigned | NO | PRI | NULL | auto_increment | | number_s | bigint(20) unsigned | YES | MUL | NULL | | | number_e | bigint(20) unsigned | YES | MUL | NULL | | | source | varchar(50) | YES | | NULL | | +-------------+---------------------+------+-----+---------+----------------+ I am trying to find if any of the values in Table A are present in Table B using the following code: $sql = "SELECT number from TableA"; $result = mysql_query($sql) or die(mysql_error()); while($row = mysql_fetch_assoc($result)) { $number = $row['number']; $sql = "SELECT source, count(source) FROM TableB WHERE number_s < $number AND number_e > $number GROUP BY source"; $re = mysql_query($sql) or die(mysql_error); while($ro = mysql_fetch_array($re)) { echo $number."\t".$ro[0]."\t".$ro[1]."\n"; } } I was hoping that the query would go fast but then for some reason, it isn't terrible fast. My explain on the select (with a particular value of "number") gives me the following: mysql> explain SELECT source, count(source) FROM TableB WHERE number_s < 1812194440 AND number_e > 1812194440 GROUP BY source; +----+-------------+------------+------+-------------------------+------+---------+------+--------+----------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+------+-------------------------+------+---------+------+--------+----------------------------------------------+ | 1 | SIMPLE | TableB | ALL | number_s,number_e | NULL | NULL | NULL | 696325 | Using where; Using temporary; Using filesort | +----+-------------+------------+------+-------------------------+------+---------+------+--------+----------------------------------------------+ 1 row in set (0.00 sec) Is there any optimization that I can squeeze out of this? I tried writing a stored procedure for the same task but it doesn't even seem to work in the first place... It doesn't give any syntax errors... I tried running it for a day and it was still running which felt odd. CREATE PROCEDURE Filter() Begin DECLARE number BIGINT UNSIGNED; DECLARE x INT; DECLARE done INT DEFAULT 0; DECLARE cur1 CURSOR FOR SELECT number FROM TableA; DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1; CREATE TEMPORARY TABLE IF NOT EXISTS Flags(number bigint unsigned, count int(11)); OPEN cur1; hist_loop: LOOP FETCH cur1 INTO number; SELECT count(*) from TableB WHERE number_s < number AND number_e > number INTO x; IF done = 1 THEN LEAVE hist_loop; END IF; IF x IS NOT NULL AND x>0 THEN INSERT INTO Flags(number, count) VALUES(number, x); END IF; END LOOP hist_loop; CLOSE cur1; END

    Read the article

  • How to Link VS2010 Database Project and LINQ to SQL

    - by Jason
    As I am working with the new database projects in VS2010, and as I am learning LINQ to SQL, I am curious as to the best way to link the two groups of information so that when I update one, the other updates along with it. From my research here at SO, as well as in Google, it appears the general rule of thumb is: "Build the database, and then create your LINQ to SQL classes." Of course, if I make a change in my database, the LINQ to SQL doesn't update automatically and I have to do it by hand. This is fairly simple right now as my database is small, but I am curious if there is an easier way for this to happen. In addition, the LINQ to SQL tool is pretty nice. The ability to create tables, add associations, and even create inheritance is very simple. As my second question, I am curious as to whether or not VS2010 can work the other way - I design the database in the DBLM file and then link it back to my database project. I appreciate any help with either of these two questions. I'm really interested in making this as easy as possible to reduce errors during development and improve the speed at which changes can be made.

    Read the article

  • Selecting a multi-dimensional array in LINQ

    - by mckhendry
    I have a task where I need to translate a DataTable to a two-dimensional array. That's easy enough to do by just looping over the rows and columns (see example below). private static string[,] ToArray(DataTable table) { var array = new string[table.Rows.Count,table.Columns.Count]; for (int i = 0; i < table.Rows.Count; ++i) for (int j = 0; j < table.Columns.Count; ++j) array[i, j] = table.Rows[i][j].ToString(); return array; } What I'd really like to do is use a select statement in LINQ to generate that 2D array. Unfortunately it looks like there is no way in LINQ to select a multidimensional array. Yes, I'm aware that I can use LINQ to select a jagged array, but that's not what I want. Is my assumption correct, or is there a way to use LINQ to select a multi-dimensional array?

    Read the article

  • Merging sequences by type With LINQ

    - by jankor
    I want to use LINQ to convert this IEnumerable<int>[] value1ByType = new IEnumerable<int>[3]; value1ByType[0]= new [] { 0}; value1ByType[1]= new [] {10,11}; value1ByType[2]= new [] {20}; var value2ToType = new Dictionary<int,int> { {100,0}, {101,1}, {102,2}, {103,1}}; to this var value2ToValue1 = new Dictionary<int,int> { {100, 0}, {101,10}, {102,20}, {103,11}}; Is there a way to do this with LINQ? Without LINQ I would use multiple IEnumerators, one for each IEnumerable of value1ByType. like this: // create enumerators var value1TypeEnumerators = new List<IEnumerator<int>>(); for (int i = 0; i < value1ByType.Length; i++) { value1TypeEnumerators.Add(value1ByType[i].GetEnumerator()); value1TypeEnumerators[i].MoveNext(); } // create wanted dictionary var value2ToValue1 = new Dictionary<int, int>(); foreach (var item in Value2ToType) { int value1=value1TypeEnumerators[item.Value].Current; value2ToValue1.Add(item.Key, value1); value1TypeEnumerators[item.Value].MoveNext(); } Any Idea how to do this in LINQ?

    Read the article

  • LINQ Query please help C#.Net.

    - by Paul Matthews
    I'm very new to LINQ and struggling to find the answers. I have a simple SQL query. Select ID, COUNT(ID) as Selections, OptionName, SUM(Units) as Units FROM tbl_Results GROUP BY ID, OptionName. The results I got were: '1' '4' 'Approved' '40' '2' '1' 'Rejected' '19' '3' '2' 'Not Decided' '12' Due to having to encrypt all my data in the database I'm unable to do sums. Therefore I have now brought back the data and decrypt it in the application layer. Results would be: '1' 'Approved' '10' '3' 'Not Deceided' '6' '2' 'Rejected' '19' '1' 'Approved' '15' '1' 'Approved' '5' '3' 'Not Deceided' '6' '1' 'Approved' '10' using a simple class I have called back the above results, and put them in a list class. public class results { public int ID {get;set;} public string OptionName {get;set;} public int Unit {get;set;} } I almost have the LINQ query to bring back the results like the SQL query at the top var q = from r in Results group p.Unit by p.ID int g select new {ID = g.Key, Selections = g.Count(), Units = g.Sum()}; How do I ensure my LINQ query also give me the Option Name? Also if I created a class called Statistics to hold my results how would I modify the LINQ query to give me list result set? public class results { public int ID {get;set;} public int NumberOfSelections { get; set; } public string OptionName {get;set;} public int UnitTotal {get;set;} }

    Read the article

  • Show me your Linq to SQL architectures!

    - by Brad Heller
    I've been using Linq to SQL for a new implementation that I've been working on. I have about 5000 lines of code and am a little ways from a solid demo. I've been pretty satisfied with Linq to SQL so far -- the tools are excellent and pretty painless and it allows you to get a DAL up and running quickly. That said, there are some major draw backs that I just keep hitting over and over again. Namely how to handle separation of concerns between my DAL and my business layer and juggling that with different data contexts. Here is the architecture I've been using: My repositories do all my data access and they return Linq to SQL objects. Each of my Linq to SQL objects implements an IDetachable interface. A typical implementation looks like this: partial class PaymentDetail : IDetachable { #region IDetachable Members public bool IsAttached { get { return PropertyChanging != null; } } public void Detach() { if (IsAttached) { PropertyChanged = null; PropertyChanging = null; Transaction.Detach(); } } #endregion } Every time I do a DAL operation in my repository I "detach" when I'm done with the object (and it should theoretically detach from any child objects) to remove the DataContext's context. Like I said, this works pretty well, but there are some edge cases that seem to be a big pain in the ass. For instance, my Transaction object has many PaymentDetails. Even when there are no PaymentDetails in that collection it's still attached to the DataContext's context! Thus, if I try to update (I update by Attach()ing to the object and then SubmitChanges()) I get that dreaded "An attempt has been made to Attach or Add an entity that is not new, perhaps having been loaded from another DataContext. This is not supported." message. Anyway, I'm starting to doubt that this technology was a good gamble. Has anyone got a decent architecture that they're willing to share? I'd really love to use this technology but I feel like I spend 1/3 of my time just debugging is retarded quirks!

    Read the article

  • VB.NET switching from ADO.NET to LINQ

    - by Cj Anderson
    I'm VERY new to Linq. I have an application I wrote that is in VB.NET 2.0. Works great, but I'd like to switch this application to Linq. I use ADO.NET to load XML into a datatable. The XML file has about 90,000 records in it. I then use the Datatable.Select to perform searches against that Datatable. The search control is a free form textbox. So if the user types in terms it searches instantly. Any further terms that are typed in continue to restrict the results. So you can type in Bob, or type in Bob Barker. Or type in Bob Barker Price is Right. The more criteria typed in the more narrowed your result. I bind the results to a gridview. Moving forward what all do I need to do? From a high level, I assume I need to: 1) Go to Project Properties -- Advanced Compiler Settings and change the Target framework to 3.5 from 2.0. 2) Add the reference to System.XML.Linq, Add the Imports statement to the classes. So I'm not sure what the best approach is going forward after that. I assume I use XDocument.Load, then my search subroutine runs against the XDocument. Do I just do the standard Linq query for this sort of repeated search? Like so: var people = from phonebook in doc.Root.Elements("phonebook") where phonebook.Element("userid") = "whatever" select phonebook; Any tips on how to best implement?

    Read the article

  • Alternatives to LINQ To SQL on high loaded pages

    - by Alex
    To begin with, I LOVE LINQ TO SQL. It's so much easier to use than direct querying. But, there's one great problem: it doesn't work well on high loaded requests. I have some actions in my ASP.NET MVC project, that are called hundreds times every minute. I used to have LINQ to SQL there, but since the amount of requests is gigantic, LINQ TO SQL almost always returned "Row not found or changed" or "X of X updates failed". And it's understandable. For instance, I have to increase some value by one with every request. var stat = DB.Stats.First(); stat.Visits++; // .... DB.SubmitChanges(); But while ASP.NET was working on those //... instructions, the stats.Visits value stored in the table got changed. I found a solution, I created a stored procedure UPDATE Stats SET Visits=Visits+1 It works well. Unfortunately now I'm getting more and more moments like that. And it sucks to create stored procedures for all cases. So my question is, how to solve this problem? Are there any alternatives that can work here? I hear that Stackoverflow works with LINQ to SQL. And it's more loaded than my site.

    Read the article

  • LINQ Joins - Performance

    - by Meiscooldude
    I am curious on how exactly LINQ (not LINQ to SQL) is performing is joins behind the scenes in relation to how Sql Server performs joins. Sql Server before executing a query, generates an Execution Plan. The Execution Plan is basically an Expression Tree on what it believes is the best way to execute the query. Each node provides information on whether to do a Sort, Scan, Select, Join, ect. On a 'Join' node in our execution plan, we can see three possible algorithms; Hash Join, Merge Join, and Nested Loops Join. Sql Server will choose which algorithm to for each Join operation based on expected number of rows in Inner and Outer tables, what type of join we are doing (some algorithms don't support all types of joins), whether we need data ordered, and probably many other factors. Join Algorithms: Nested Loop Join: Best for small inputs, can be optimized with ordered inner table. Merge Join: Best for medium to large inputs sorted inputs, or an output that needs to be ordered. Hash Join: Best for medium to large inputs, can be parallelized to scale linearly. LINQ Query: DataTable firstTable, secondTable; ... var rows = from firstRow in firstTable.AsEnumerable () join secondRow in secondTable.AsEnumerable () on firstRow.Field<object> (randomObject.Property) equals secondRow.Field<object> (randomObject.Property) select new {firstRow, secondRow}; SQL Query: SELECT * FROM firstTable fT INNER JOIN secondTable sT ON fT.Property = sT.Property Sql Server might use a Nested Loop Join if it knows there are a small number of rows from each table, a merge join if it knows one of the tables has an index, and Hash join if it knows there are a lot of rows on either table and neither has an index. Does Linq choose its algorithm for joins? or does it always use one?

    Read the article

< Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >