Search Results

Search found 46790 results on 1872 pages for 'type systems'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 162/1872 | < Previous Page | 158 159 160 161 162 163 164 165 166 167 168 169  | Next Page >

  • What resources will help me understand the fundamentals of Relational Database Systems.

    - by Rachel
    This are few of the fundamental database questions which has always given me trouble. I have tried using google and wiki but I somehow I miss out on understanding the functionality rather than terminology. If possible would really appreciate if someone can share more insights on this questions using some visual representative examples. What is a key? A candidate key? A primary key? An alternate key? A foreign key? What is an index and how does it help your database? What are the data types available and when to use which ones?

    Read the article

  • What are the prerequisites for learning embedded systems programming ?

    - by WarDoGG
    I have completed my graduation in Computer engineering. We had some basic electronics courses in Digital signal processing, Information theory etc but my primary field is Programming. However, i was looking to get into Embedded sytems programming with NO knowledge of how it is done. However, i am very keen on going into this field. My questions : what are the languages used to program embedded system programs ? Will i be able to learn without having any basics in electronics ? any other prerequisites that i should know ?

    Read the article

  • Why doesn't GCC produce a warning when assigning a signed literal to an unsigned type?

    - by maerics
    Several questions on this website reveal pitfalls when mixing signed and unsigned types and most compilers seem to do a good job about generating warnings of this type. However, GCC doesn't seem to care when assigning a signed constant to an unsigned type! Consider the following program: /* foo.c */ #include <stdio.h> int main(void) { unsigned int x=20, y=-30; if (x > y) { printf("%d > %d\n", x, y); } else { printf("%d <= %d\n", x, y); } return 0; } Compilation with GCC 4.2.1 as below produces no output on the console: gcc -Werror -Wall -Wextra -pedantic foo.c -o foo The resulting executable generates the following output: $ ./foo 20 <= -30 Is there some reason that GCC doesn't generate any warning or error message when assigning the signed value -30 to the unsigned integer variable y?

    Read the article

  • Why does Java's TreeSet not specify that its type parameter must extend Comparable?

    - by Tarski
    e.g. The code below throws a ClassCastException when the second Object is added to the TreeSet. Couldn't TreeSet have been written so that the type parameter can only be a Comparable type? i.e. TreeSet would not compile because Object is not Comparable. That way generics actually do their job - of being typesafe. import java.util.TreeSet; public class TreeSetTest { public static void main(String [] args) { TreeSet<Object> t = new TreeSet<Object>(); t.add(new Object()); t.add(new Object()); } }

    Read the article

  • Why can one aliased C# Type not be accessed by another?

    - by jdk
    good stuff // ok to alias a List Type using AliasStringList = System.Collections.Generic.List<string>; // and ok to alias a List of Lists like this using AliasListOfStringList1 = System.Collections.Generic.List<System.Collections.Generic.List<string>>; bad stuff // However **error** to alias another alias using AliasListOfStringList2 = System.Collections.Generic.List<AliasStringList>; Produces the compile error The type or namespace name 'AliasStringList' could not be found (are you missing a using directive or an assembly reference?) Note: this is the using directive not the using statement.

    Read the article

  • Why is Read-Modify-Write necessary for registers on embedded systems?

    - by Adam Shiemke
    I was reading http://embeddedgurus.com/embedded-bridge/2010/03/different-bit-types-in-different-registers/, which said: With read/write bits, firmware sets and clears bits when needed. It typically first reads the register, modifies the desired bit, then writes the modified value back out and I have run into that consrtuct while maintaining some production code coded by old salt embedded guys here. I don't understand why this is necessary. When I want to set/clear a bit, I always just or/nand with a bitmask. To my mind, this solves any threadsafe problems, since I assume setting (either by assignment or oring with a mask) a register only takes one cycle. On the other hand, if you first read the register, then modify, then write, an interrupt happening between the read and write may result in writing an old value to the register. So why read-modify-write? Is it still necessary?

    Read the article

  • How to marshal the type of "Cstring" in .NET Compact Framework(C#)?

    - by SmartJJ
    How to marshal the type of "Cstring" in .NET Compact Framework(C#)? DLLname:Test_Cstring.dll(OS is WinCE 5.0),source code: extern "C" __declspec(dllexport) int GetStringLen(CString str) { return str.GetLength(); } I marshal that in .NET Compact Framework(C#),for example: [DllImport("Test_Cstring.dll", EntryPoint = "GetStringLen", SetLastError = true)] public extern static int GetStringLen(string s); private void Test_Cstring() { int len=-1; len=GetStringLen("abcd"); MessageBox.Show("Length:"+len.ToString()); //result is -1,so PInvoke is unsuccessful! } The Method of "GetStringLen" in .NET CF is unsuccessful! How to marshal this type of "Cstring"? Any information about it would be very appreciated!

    Read the article

  • Does Displaytag stash the "media type" in a page or request attribute?

    - by Pointy
    When you enable "export" from Displaytag, the tag code gives you links with special magic parameters that the tag recognizes as indicators that the table contents should be exported (as CSV, Excel, whatever). Well I'm interested in detecting the media type so that (for example) I can exclude columns that make no sense in an export (embedded action buttons, for one thing, or checkboxes for row selection). I suppose I could write a table decorator and use that to stick the media type on the request, but it'd be nice to avoid that if the tag already does it. The documentation is not clear on the subject; I guess I can start digging through the source code too.

    Read the article

  • What is preferred accessible and semantically correct method to code this type of data design?

    - by jitendra
    What is preferred accessible and semantically correct method to code this type of data design? Table UL, LI DIV,SPAN For icons should i use for each place or i should is icon from CSS sprites? If we use css sprite here then how to code, and what will happen when images will be disabled ? Every link will open in new window and I have to indicate about file size also for both sighted and blind users? So what is the best method to make this design and what is best method to show icon and to indicate all type of users that file will open in new window and what is file size? Content of table should be accessible and understandable in as good as possible manner in all conditions For sighted user even if images are disabled for screen user for text browser user and if css is disabled And What is the role of Filenames of PDF, video, audio here?

    Read the article

  • Access NFS share from cygwin?

    - by Jason Voegele
    We have a Windows 2003 Server on which we have installed Microsoft's Services for UNIX, and we have mounted a few NFS shares that contain shared resources that we need to access from this box. When I log in to this server with remote desktop, I am able to browse the contents of the NFS shares and everything works fine. However, one use case that we have is that we need to access this server using SSH, and still be able to access the NFS shares. We are running the Cygwin SSH daemon to provide SSH access to the server, but for some reason when we log in to the Windows 2003 server using SSH we can no longer access the NFS shares. To demonstrate, here is the output of the 'mount' command, first from a Cygwin shell when logged in with remote desktop: $ mount C:/cygwin/bin on /usr/bin type ntfs (binary,auto) C:/cygwin/lib on /usr/lib type ntfs (binary,auto) C:/cygwin on / type ntfs (binary,auto) C: on /cygdrive/c type ntfs (binary,posix=0,user,noumount,auto) O: on /cygdrive/o type nfs (binary,posix=0,user,noumount,auto) P: on /cygdrive/p type nfs (binary,posix=0,user,noumount,auto) Z: on /cygdrive/z type nfs (binary,posix=0,user,noumount,auto) And now, the same 'mount' command when logged in with SSH: $ mount C:/cygwin/bin on /usr/bin type ntfs (binary,auto) C:/cygwin/lib on /usr/lib type ntfs (binary,auto) C:/cygwin on / type ntfs (binary,auto) C: on /cygdrive/c type ntfs (binary,posix=0,user,noumount,auto) Notice the missing O: P: and Z: NFS shares in the latter. Can anyone tell me why I am unable to see these NFS shares when logged in with SSH? Thanks!

    Read the article

  • Are indivisible operations still indivisible on multiprocessor and multicore systems?

    - by Steve314
    As per the title, plus what are the limitations and gotchas. For example, on x86 processors, alignment for most data types is optional - an optimisation rather than a requirement. That means that a pointer may be stored at an unaligned address, which in turn means that pointer might be split over a cache page boundary. Obviously this could be done if you work hard enough on any processor (picking out particular bytes etc), but not in a way where you'd still expect the write operation to be indivisible. I seriously doubt that a multicore processor can ensure that other cores can guarantee a consistent all-before or all-after view of a written pointer in this unaligned-write-crossing-a-page-boundary situation. Am I right? And are there any similar gotchas I haven't thought of?

    Read the article

  • How can I implement incremental (find-as-you-type) search on command line?

    - by florianbw
    I'd like to write small scripts which feature incremental search (find-as-you-type) on the command line. Use case: I have my mobile phone connected via USB, Using gammu --sendsms TEXT I can write text messages. I have the phonebook as CSV, and want to search-as-i-type on that. What's the easiest/best way to do it? It might be in bash/zsh/Perl/Python or any other scripting language. Edit: Solution: Modifying Term::Complete (http://search.cpan.org/~jesse/perl-5.12.0/lib/Term/Complete.pm) did what I want. See below for the answer.

    Read the article

  • LINQ - Select Statement - The null value cannot be assigned to a member with type System.Int32 which

    - by thiag0
    I am trying to achieve the following... _4S.NJB_Request request = (from r in db.NJB_Requests where r.RequestId == referenceId select r).Take(1).SingleOrDefault(); Getting the following exception... Message: The null value cannot be assigned to a member with type System.Int32 which is a non-nullable value type. StackTrace: at System.Data.Linq.SqlClient.SqlProvider.Execute(Expression query, QueryInfo queryInfo, IObjectReaderFactory factory, Object[] parentArgs, Object[] userArgs, ICompiledSubQuery[] subQueries, Object lastResult) at System.Data.Linq.SqlClient.SqlProvider.ExecuteAll(Expression query, QueryInfo[] queryInfos, IObjectReaderFactory factory, Object[] userArguments, ICompiledSubQuery[] subQueries) at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query) at System.Data.Linq.DataQuery`1.System.Linq.IQueryProvider.Execute[S](Expression expression) at System.Linq.Queryable.SingleOrDefault[TSource](IQueryable`1 source) at DAL.SqlDataProvider.MarkNJBPCRequestAsComplete(Int32 referenceId, Int32 processState) I have verified that 'referenceId' does have a value. Anyone know why this would happen in a select statement? Thanks!

    Read the article

  • Possible to use Tables of same type in Linq to SQL?

    - by Schneider
    Lets say I've got an object model, where I have many collections of the same type. For example something like class StockMarketData { List<SummaryData> WeeklySummary; List<SummaryData> MonthlySummary; } class SummaryData { DateTime DateTime {get; set;} double Value {get; set;} } Those lists will map onto database tables. If you actually use L2S to generate a model from the database you will get something like: class StockMarketData { List<WeeklySummaryData> WeeklySummary; List<MonthlySummaryData> MonthlySummary; } Even though WeeklySummaryData and MonthlySummaryData have the same shape. Is it possible for Linq to SQL to create tables from a database of summary data, but get each table to contain the same type (such as shown in the top example).

    Read the article

  • Using unmanaged code, how can I find a type that has a given custom attribute assigned to it?

    - by Andrew
    I had thought I could enumerate the types using IMetaDataImport.EnumTypeDefs and for each of the tokens returned, call IMetaDataImport.EnumCustomAttributes. This works, in so much as I get an array of mdCustomAttribute tokens. Using these tokens I can get a metadata token representing the Type of the returned custom attribute, by calling IMetaDataImport.GetCustomAttributeProps. Comparing my results against ILDASM, I can see that this matches the "CustomAttribute Type" that ILDASM reports. However, I cannot work out how to determine the "CustomAttributeName" that ILDASM reports. This is what I really want! While I would be interested in knowing how to get the CustomAttributeName, I would settle for an alternate approach to solving the problem.

    Read the article

  • Can this be done with single SQL query

    - by Ghostrider
    I'm using MySQL. I have a table Type SubType 1 1 1 5 1 6 1 8 2 2 2 3 3 1 3 2 3 3 For each type there is some number of subtypes. For every subtype in a type there is a corresponding subtype in the next type: (1,1) => (2,2) (1,5) => (2,3) (1,6) => (2,2) (1,8) => (2,3) (2,2) => (3,1) (2,3) => (3,2) In case you haven't seen the pattern, here it is: you sort both current and next types by subtype, then in the next type you get subtype in the same position as your current subtype in current type is. If there are more subtypes in the current type that in the next one, you warp around and start from the first subtype in the next type. Is it possible to construct a query that takes current type and subtype and returns corresponding subtype in the next type?

    Read the article

  • How to access a structure member in a function that get it as void* type?

    - by Ahmad
    I want to have a function that accepts different type of structures as argument. So, since I don't have a specific type, I have to use void*. Now question is: when I pass a structure to this function, how can I access a known member of this structure inside the function? Specifically, I know that all structures have str1 as a member and I want, for example, print it. Here is a sample code: struct { char* str1; float tt1; } var1 = {"This is me", 12}; struct { char* str1; int tt2; } var2 = {"This is you", 18}; void printStruct(void* str) { printf("\n the structure string is %s", ??); //can I put something in ?? to print the string? } main(....) { printStruct(&var1); printStruct(&var2); }

    Read the article

  • Exposing a service to external systems - How should I design the contract?

    - by Larsi
    Hi! I know this question is been asked before here but still I'm not sure what to select. My service will be called from many 3 party system in the enterprise. I'm almost sure the information the service will collect (MyBigClassWithAllInfo) will change during the products lifetime. Is it still a good idea to expose objects? This is basically what my two alternatives: [ServiceContract] public interface ICollectStuffService { [OperationContract] SetDataResponseMsg SetData(SetDataRequestMsg dataRequestMsg); } // Alternative 1: Put all data inside a xml file [DataContract] public class SetDataRequestMsg { [DataMember] public string Body { get; set; } [DataMember] public string OtherPropertiesThatMightBeHandy { get; set; } // ?? } // Alternative 2: Expose the objects [DataContract] public class SetDataRequestMsg { [DataMember] public Header Header { get; set; } [DataMember] public MyBigClassWithAllInfo ExposedObject { get; set; } } public class SetDataResponseMsg { [DataMember] public ServiceError Error { get; set; } } The xml file would look like this: <?xml version="1.0" encoding="utf-8"?> <Message>   <Header>     <InfoAboutTheSender>...</InfoAboutTheSender>   </Header>   <StuffToCollectWithAllTheInfo>   <stuff1>...</stuff1> </StuffToCollectWithAllTheInfo> </Message> Any thought on how this service should be implemented? Thanks Larsi

    Read the article

  • Missing parameter error after running MySql query

    - by annelie
    Hello, I'm completely new to MySql and haven't used SqlDataSource with UpdateParameters before, so I'm probably missing something very obvious. When trying to update a record, the update does happen but then throws an error saying "'id' parameter is missing at the statement". So the query works and the database gets updated as it should, but an error is thrown afterwards. These are the update parameters: <UpdateParameters> <asp:Parameter Name="business_name" Type="string" Size="256" /> <asp:Parameter Name="addr_line_1" Type="string" Size="256" /> <asp:Parameter Name="addr_line_2" Type="string" Size="256" /> <asp:Parameter Name="addr_line_3" Type="string" Size="256" /> <asp:Parameter Name="postcode" Type="string" Size="32" /> <asp:Parameter Name="county" Type="string" Size="128" /> <asp:Parameter Name="town_city" Type="string" Size="256" /> <asp:Parameter Name="tl_url" Type="string" Size="256" /> <asp:Parameter Name="customer_id" Type="string" Size="16" /> <asp:Parameter Name="region_id" Type="Int16" /> <asp:Parameter Name="description" Type="string" Size="1024" /> <asp:Parameter Name="approval_status" Type="string" Size="1" /> <asp:Parameter Name="tl_user_name" Type="string" Size="256" /> <asp:Parameter Name="phone" Type="string" Size="50" /> <asp:Parameter Name="uploaders_own" Type="Int16" /> </UpdateParameters> Here's the update statement: UPDATE myTable SET business_name = ?, addr_line_1 = ?, addr_line_2 = ?, addr_line_3 = ?, postcode = ?, county = ?, town_city = ?, tl_url = ?, customer_id = ?, region_id = ?, description = ?, approval_status = ?, tl_user_name = ?, phone = ?, uploaders_own = ? WHERE id = " + id Here's the stack trace: [InvalidOperationException: 'id' parameter is missing at the statement] CoreLab.MySql.r.a() +775 CoreLab.MySql.r.a(Int32& A_0, ArrayList& A_1) +448 CoreLab.MySql.x.e() +398 CoreLab.MySql.x.o() +89 CoreLab.MySql.MySqlCommand.a(CommandBehavior A_0, IDisposable A_1, Int32 A_2, Int32 A_3) +1306 CoreLab.Common.DbCommandBase.ExecuteDbDataReader(CommandBehavior behavior) +310 System.Data.Common.DbCommand.ExecuteReader() +12 CoreLab.Common.DbCommandBase.ExecuteNonQuery() +64 System.Web.UI.WebControls.SqlDataSourceView.ExecuteDbCommand(DbCommand command, DataSourceOperation operation) +386 System.Web.UI.WebControls.SqlDataSourceView.ExecuteUpdate(IDictionary keys, IDictionary values, IDictionary oldValues) +325 System.Web.UI.DataSourceView.Update(IDictionary keys, IDictionary values, IDictionary oldValues, DataSourceViewOperationCallback callback) +92 System.Web.UI.WebControls.DetailsView.HandleUpdate(String commandArg, Boolean causesValidation) +837 System.Web.UI.WebControls.DetailsView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) +509 System.Web.UI.WebControls.DetailsView.OnBubbleEvent(Object source, EventArgs e) +95 System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37 System.Web.UI.WebControls.DetailsViewRow.OnBubbleEvent(Object source, EventArgs e) +113 System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37 System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e) +118 System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) +135 System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10 System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13 System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +175 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1565 Does anyone know what I'm doing wrong? Thanks, Annelie

    Read the article

  • Better explanation of $this-> in this example please

    - by Doug
    Referring to this question: http://stackoverflow.com/questions/2035449/why-is-oop-hard-for-me class Form { protected $inputs = array(); public function makeInput($type, $name) { echo '<input type="'.$type.'" name="'.$name.'">'; } public function addInput($type, $name) { $this->inputs[] = array("type" => $type, "name" => $name); } public function run() { foreach($this->inputs as $array) { $this->makeInput($array['type'], $array['name']; } } } $form = new form(); $this->addInput("text", "username"); $this->addInput("text", "password");** Can I get a better explanation of what the $this->input[] is doing in this part: public function addInput($type, $name) { $this->inputs[] = array("type" => $type, "name" => $name); }

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 158 159 160 161 162 163 164 165 166 167 168 169  | Next Page >