Search Results

Search found 8749 results on 350 pages for 'nullable types'.

Page 218/350 | < Previous Page | 214 215 216 217 218 219 220 221 222 223 224 225  | Next Page >

  • mysql data type confusion

    - by zen
    So this is more of a generalized question about MySQLs data types. I'd like to store a 5-digit US zip code (zip_code) properly in this example. A county has 10 different cities and 5 different zip codes. city | zip code -------+---------- city 0 | 33333 city 1 | 11111 city 2 | 22222 city 3 | 33333 city 4 | 44444 city 5 | 55555 city 6 | 33333 city 7 | 33333 city 8 | 44444 city 9 | 22222 I would typically structure a table like this as varchar(50), int(5) and not think twice about it. (1) If we wanted to ensure that this table had only one of 5 different zip codes we should use the enum data type, right? Now think of a similar scenario on a much larger scale. In a state, there are five-hundred cities with 418 different zip codes. (2) Should I store 418 zip codes as an enum data type OR as an int and create another table to reference?

    Read the article

  • Typical text encoding and EOL behavior on mobile devices

    - by Dan W
    Typical things to worry about when dealing with text are the BOM/signature, encoding, and the end of line (EOL) char/chars. I know that Windows often favours \r\n (CR+LF) and Mac/Linux favours \n (LF), but how about popular mobile devices such as the iPhone and Android? Do typical apps on those platforms favour one or the other (or maybe even \r for iOS)? I'll supply both types to the user just in case, but I'd like to choose one as default. Also, which text encodings are mobiles most likely to use - UTF-8, iso-8859-1, Windows 1252 (or other default codepage) or maybe even UTF-16? And if they use UTF-8/16, are they likely to need (or require not having) a BOM/signature? What is the typical behavior here? Once again, I'll supply a range of encodings to the user just in case, but I'd like to prioritize or use certain encodings as default if it's appropriate.

    Read the article

  • What if I put two kinds of encoded strings, say utf-8 and utf-16, in one file?

    - by jonny
    In Python, for example: f = open('test','w') f.write('this is a test\n'.encode('utf-16')) f.write('another test\n'.encode('utf-8')) f.close() That file gets messy when I re-open it: f = open("test") print f.readline().decode('utf-16') # it leads to UnicodeDecodeError print f.readline().decode('utf-8') # it works fine However if I keep the texts encoded in one style (say utf-16 only), it could read back ok. So I'm guessing mixing two types of encoding in the same file is wrong and couldn't be decoded back, even if I do know the encoding rules of each specific string? Any suggestion is welcome, thank you!

    Read the article

  • Something like System.Diagnostics.Process.Start to run a stream

    - by phenevo
    Hi, I get from server images and videos by stream. Now I'm saving it: Stream str = client.GetFile(path); using (var outStream = new FileStream(@"c:\myFile.jpg", FileMode.Create)) { var buffer = new byte[4096]; int count; while ((count = str.Read(buffer, 0, buffer.Length)) > 0) { outStream.Write(buffer, 0, count); } } I can be jpg, mpg, flv and a lot of other multimedia types (Before I get stream I know what is a extension of this file). Now I want to not save it , bu run direct from stream. Is it possible ??

    Read the article

  • MPI4Py Scatter sendbuf Argument Type?

    - by Noel
    I'm having trouble with the Scatter function in the MPI4Py Python module. My assumption is that I should be able to pass it a single list for the sendbuffer. However, I'm getting a consistent error message when I do that, or indeed add the other two arguments, recvbuf and root: File "code/step3.py", line 682, in subbox_grid i = mpi_communicator.Scatter(station_range, station_data) File "Comm.pyx", line 427, in mpi4py.MPI.Comm.Scatter (src/ mpi4py_MPI.c:44993) File "message.pxi", line 321, in mpi4py.MPI._p_msg_cco.for_scatter (src/mpi4py_MPI.c:14497) File "message.pxi", line 232, in mpi4py.MPI._p_msg_cco.for_cco_send (src/mpi4py_MPI.c:13630) File "message.pxi", line 36, in mpi4py.MPI.message_simple (src/ mpi4py_MPI.c:11904) ValueError: message: expecting 2 or 3 items Here is the relevant code snipped, starting a few lines above 682 mentioned above. for station in stations #snip--do some stuff with station station_data = [] station_range = range(1,len(station)) mpi_communicator = MPI.COMM_WORLD i = mpi_communicator.Scatter(station_range, nsm) #snip--do some stuff with station[i] nsm = combine(avg, wt, dnew, nf1, nl1, wti[i], wtm, station[i].id) station_data = mpi_communicator.Gather(station_range, nsm) I've tried a number of combinations initializing station_range, but I must not be understanding the Scatter argument types properly. Does a Python/MPI guru have a clarification this?

    Read the article

  • Cherokee rule failover

    - by phretor
    I have a Cherokee virtual host configured as follows: 1st rule: "Directory /" -> HTTP Reverse Proxy 2nd rule: "Directory /" -> uWSGI I know the second rule is useless because it's never triggered. However, the first rule seldom returns a 504 Gateway Timeout error so I was thinking of failing over the second rule, yet I don't know how to achieve this. Is it possible? Unfortunately, I cannot use only one rule with load balanced information sources, because I use two different types of information sources (i.e., pure HTTP and WSGI).

    Read the article

  • Database Design: A proper table design for large number of column values.

    - by Jake
    I wish to perform an experiment many different times. After every trial, I am left with a "large" set of output statistics -- let's say, 1000. I would like to store the outputs of my experiments in a table, but what's the best way...? Option 1 Have a table with 1000 columns. Seems like a bad idea. What if the number of statistics one day exceeds the maximum number of columns? Option 2 Have a table with three columns. Let's say, ID, StatisticType, and StatisticValue. That way, you can have as many statistics as you want. However, reading a single experiments statistics becomes more complicated. Moreover, what if different statistics are different data types?? Any suggestions?

    Read the article

  • IEnumerable and IEnumerator in the same class, bad idea?

    - by David Rutten
    Is this a bad idea? Private Class GH_DataStructureEnumerator(Of Q As Types.IGH_Goo) Implements IEnumerable(Of Q) Implements IEnumerator(Of Q) .... .... 'Current, MoveNext, Reset etc.' .... .... Public Function GetEnumerator_Generic() As IEnumerator(Of Q) _ Implements IEnumerable(Of Q).GetEnumerator Return Me End Function End Class This class is only visible as an IEnumerable(Of T) readonly property, and it saves me an additional class that wraps IEnumerator(Of T). But somehow it just seems wrong. Is there a better way?

    Read the article

  • PHP specifying a fixed include source for scripts in different directories

    - by Extrakun
    I am currently doing unit testing, and use folders to organize my test cases. All cases pertaining to managing of user accounts, for example, go under \tests\accounts. Over time, there are more test cases, and I begin to seperate the cases by types, such as \tests\accounts\create, \tests\account\update and etc. However, one annoying problem is I have to specify the path to a set of common includes. I have to use includes like this: include_once ("../../../../autoload.php"); include_once ("../../../../init.php"); A test case in tests\accounts\ would require change to the include (one less directory level down). Is there anyway to have them somehow locating my two common includes? I understand I could set include paths within my PHP's configurations, or use server environment variables, but I would like to avoid such solutions as they make the application less portable and coupled with another layer which the programmer can't control (some web-host doesn't allow configuration of PHP's configuration settings, for example)

    Read the article

  • iOS Facebook Access Token To Get User Wall Feed (status)

    - by Felix
    [DISCLAIMER : None of the access token or ID below here are real] I've done research for three solid days and no result on how to get user wall feed(post). I have used https://graph.facebook.com/oauth/access_token?client_id=YOUR_APP_ID&client_secret=YOUR_APP_SECRET&grant_type=client_credentials and get the access token which is something like this access_token=454345994651138|bAMGfuW-ueNXGCahley7ga125HN and then https://graph.facebook.com/100005939123542/feed?access_token=454345994651138|bAMGfuW-ueNXGCahley7ga125HN It gives me general information such as user's likes, name, id, current city... but NOT user's wall posts. I've learned that there are three types of access token, which is App Token, User Token, and Page Token. In order to get user/feed by using graphAPI, I need to request to get User Token, but there's NO information in the lousy Facebook Doc! (Which frustrated me the most!) In order to generate the user access token, we need to set some permission, generate the access token, and GET the user's wall feed, which is in JSON format. My question is : How do I get the User Access Token in order to get user wall post in iOS Xcode?

    Read the article

  • How does this "&" work in this statement?

    - by aquaibm
    I know how bitwise AND works,but I don't understand how does (sourceDragMask & NSDragOperationGeneric) work here,I don't get the point.Is there anyone can explain to me?Thanks a lot. (NSDragOperation)draggingEntered:(id )sender { NSPasteboard *pboard; NSDragOperation sourceDragMask; sourceDragMask = [sender draggingSourceOperationMask]; pboard = [sender draggingPasteboard]; if ( [[pboard types] containsObject:NSColorPboardType] ) { if (sourceDragMask & NSDragOperationGeneric) { return NSDragOperationGeneric; } } return NSDragOperationNone; }

    Read the article

  • design using a readonly class in c#

    - by edosoft
    Hi Small design question here. I'm trying to develop a calculation app in C#. I have a class, let's call it InputRecord, which holds 100s of fields (multi dimensional arrays) This InputRecordclass will be used in a number of CalculationEngines. Each CalculcationEngine can make changes to a number of fields in the InputRecord. These changes are steps needed for it's calculation. Now I don't want the local changes made to the InputRecord to be used in other CalculcationEngine's classes. The first solution that comes to mind is using a struct: these are value types. However I'd like to use inheritance: each CalculationEngine needs a few fields only relevant to that engine: it's has it's own InputRecord, based on BaseInputRecord. Can anyone point me to a design that will help me accomplish this?

    Read the article

  • FileInputStream for a generic file System

    - by Akhil
    I have a file that contains java serialized objects like "Vector". I have stored this file over Hadoop Distributed File System(HDFS). Now I intend to read this file (using method readObject) in one of the map task. I suppose FileInputStream in = new FileInputStream("hdfs/path/to/file"); wont' work as the file is stored over HDFS. So I thought of using org.apache.hadoop.fs.FileSystem class. But Unfortunately it does not have any method that returns FileInputStream. All it has is a method that returns FSDataInputStream but I want a inputstream that can read serialized java objects like vector from a file rather than just primitive data types that FSDataInputStream would do. Please help!

    Read the article

  • printing uid of a file on linux system

    - by neo730
    i am learning c programming. I am trying to make my own program similar to ls command but with less options.what i am doing is taking input directory/file name as argument and then gets all directory entry with dirent struct(if it is directory) . After it i use stat() to take all information of the file but here is my problem when i use write() to print these value its fine but when i want to print these with printf() i get warninng : format ‘%ld’ expects type ‘long int’, but argument 2 has type ‘__uid_t’. I don't know what should use at place of %ld and also for other special data types.

    Read the article

  • WCF - (Custom) binary serialisation.

    - by Barguast
    I want to be able to query my database over the web, and I am wanting to use a WCF service to handle the requests and results. The problem is that due to the amount of data that can potentially be returned from these queries, I'm worried about how these results will be serialised over the network. For example, I can imagine the XML serialisation looking like: <Results> <Person Name="Adam" DateOfBirth="01/02/1985" /> <Person Name="Bob" DateOfBirth="04/07/1986" /> </Results> And the binary serialisation containing types names and other (unnecessary) metadata. Perhaps even the type name for each element in a collection? o_o Ideally, I'd like to perform the serialisation of certain 'DataContract'-s myself so I can make it super-compact. Does anyone know if this is possible, or of any articles which explain how to do custom serialisation with WCF? Thanks in advance

    Read the article

  • Read VB binary file with c# (knowing the structure)

    - by Kai
    I'd like to read a file that has been binary saved by a vb prog. the file should be read line by line, 'cause every single line represents an object with many attributes. a link looks the following: 999011011/10/1 ELW the structure of data types is: Public Type FahrzeugDAT Kennung As String * 8 Name As String * 30 Info As String * 50 StatusFzg As Integer DatumFzg As Date StatusLst As Integer DatumLst As Date TKI As Integer Folgetlg As Integer LstKurztext As String * 100 FME1 As String * 5 FME2 As String * 5 FME3 As String * 5 DME1 As String * 8 DME2 As String * 8 DME3 As String * 8 Bemerkung As String * 256 Art As Long Standort As Long End Type

    Read the article

  • Worst side effects from chars signedness. (Explanation of signedness effects on chars and casts)

    - by JustSmith
    I frequently work with libraries that use char when working with bytes in C++. The alternative is to define a "Byte" as unsigned char but that not the standard they decided to use. I frequently pass bytes from C# into the C++ dlls and cast them to char to work with the library. When casting ints to chars or chars to other simple types what are some of the side effects that can occur. Specifically, when has this broken code that you have worked on and how did you find out it was because of the char signedness? Lucky i haven't run into this in my code, used a char signed casting trick back in an embedded systems class in school. I'm looking to better understand the issue since I feel it is relevant to the work I am doing.

    Read the article

  • Android EditText within a ListView

    - by metalideath
    I have created a custom Array Adapter to bind a custom row that contains some static text and an editable EditText. I am trying to register to be notified when the user changes the text within the edit text and when notified to determine which ArrayList row the modified EditText corresponds to. In the past with other types of views such as a Spinner I could simply put a reference to the parent view and the row number into the tag for the Spinner view. And then when I was notified that the value changed I read the tag to determine how to correlate it back to the master ArrayList. The problem with registering to be notifed with an EditText change is that you do not get back a view but instead get a TextWatcher and I have no way to correlate back to the parent view or ArrayList row. What is the technique that you need to use in this circumstance?

    Read the article

  • Should I use implicit conversions to enforce preconditions?

    - by Malvolio
    It occurs to me that I could use use implicit conversions to both announce and enforce preconditions. Consider this: object NonNegativeDouble { implicit def int2nnd(d : Double) : NonNegativeDouble = new NonNegativeDouble(d) implicit def nnd2int(d : NonNegativeDouble) : Double = d.v def sqrt(n : NonNegativeDouble) : NonNegativeDouble = scala.math.sqrt(n) } class NonNegativeDouble(val v : Double ) { if (v < 0) { throw new IllegalArgumentException("negative value") } } object Test { def t1 = { val d : Double = NonNegativeDouble.sqrt(3.0); printf("%f\n", d); val n : Double = NonNegativeDouble.sqrt(-3.0); } } Ignore for the moment the actual vacuity of the example: my point is, the subclass NonNegativeDouble expresses the notion that a function only takes a subset of the entire range of the class's values. First is this: A good idea, a bad idea, or an obvious idea everybody else already knows about Second, this would be most useful with basic types, like Int and String. Those classes are final, of course, so is there a good way to not only use the restricted type in functions (that's what the second implicit is for) but also delegate to all methods on the underlying value (short of hand-implementing every delegation)?

    Read the article

  • Comparing two java objects on fly (data type not known)

    - by Narendra
    Hi All, I need to compare different data objects. Can any one tell me how can i do this. I don't know what are the data types i will get priorly. If i need to use any util from apache commons then please give reference to it. At present I am using .equals() for comparing equality of objects .It is working fine when I am comparing quality for two strings. If i am comparing java.sql.date data type then it is showing unequal even though both contains same values. Can any one suggest me on this regard. Thanks, Narendra

    Read the article

  • Ignoring generated files when using "Treat warnings as errors"

    - by krystan honour
    We have started a new project but also have this problem for an existing project. The problem is that when we compile with a warning level of 4 we also want to switch on 'Treat all warnings as errors' We are unable to do this at the moment because generated files (in particular reference.cs files) are missing things like XML comments and this generates a warning, we do not want to suppress the xml comment warnings totally out of all files just for specific types of files (namely generated code). I have thought of a way this could be achieved but am not sure if these are the best way to do this or indeed where to start :) My thinking is that we need to do something with T4 templates for the code that is generated such that it does fill in XML documentation for generated code. Does anyone have any ideas, currently I'm at well over 2k warnings (its a big project) :(

    Read the article

  • UTF-8 conversion

    - by leachianus
    Hey guys, I am grabbing a JSON array and storing it in a NSArray, however it includes JSON encoded UTF-8 strings, for example pass\u00e9 represents passé. I need a way of converting all of these different types of strings into the actual character. I have an entire NSArray to convert. Or I can convert it when it is being displayed, which ever is easiest. I found this chart http://tntluoma.com/sidebars/codes/ is there a convenience method for this or a library I can download? thanks, BTW, there is no way I can find to change the server so I can only fix it on my end...

    Read the article

  • Should I use DTOs as my data models in MVVM?

    - by JonC
    I'm currently working on what will be my first real foray into using MVVM and have been reading various articles on how best to implement it. My current thoughts are to use my data models effectively as data transfer objects, make them serializable and have them exist on both the client and server sides. It seems like a logical step given that both object types are really just collections of property getters and setters and another layer in between seems like complete overkill. Obviously there would be issues with INotifyPropertyChanged not working correctly on the server side as there is no ViewModel to which to communicate, but as long as we are careful about constructing our proper domain model objects from data models in the service layer and not dealing the the data models on the server side I don't think it should be a big issue. I haven't found too much info about this approach in my reading, so I would like to know if this is a pretty standard thing, is this just assumed to be the de facto way of doing MVVM in a multi-tier environment? If I've got completely the wrong idea about things then thoughts on other approaches would be appreciated too.

    Read the article

  • Google analytics-style custom report builder UI

    - by gregmac
    I'm looking for a reporting engine/UI that can be integrated into a product, which has a UI along the lines of Google Analytics' Custom Reports builder. Is anyone aware of such a thing? The data is in our case is not page views/visitors/etc, but is similar in nature, in that there are limited entities or types of data, but each entity has many attributes/columns and many different ways of aggregating data (or in GA-style speak, metrics and dimensions). The analytics-style UI is very intuitive and allows many reports to be created in powerful ways, without having to know SQL. I have preference for a web-based tool (seeing that it is 2010 and this is a web app -- I mention only because it seems the vast majority of reporting tools still have only a non-web-based creation tool).

    Read the article

  • Creating a method that is simultaneously an instance and class method

    - by Mike Axiak
    In Python, I'd like to be able to create a function that behaves both as a class function and an instance method, but with the ability to change behaviors. The use case for this is for a set of serializable objects and types. As an example: >>> class Thing(object): #... >>> Thing.to_json() 'A' >>> Thing().to_json() 'B' I know that given the definition of classmethod() in funcobject.c in the Python source, this looks like it'd be simple with a C module. Is there a way to do this from within python? Thanks!

    Read the article

< Previous Page | 214 215 216 217 218 219 220 221 222 223 224 225  | Next Page >