Search Results

Search found 6241 results on 250 pages for 'unsigned integer'.

Page 170/250 | < Previous Page | 166 167 168 169 170 171 172 173 174 175 176 177  | Next Page >

  • Is there a PHP library that performs MySQL Data Validation and Sanitization According to Column Type

    - by JW
    Do you know of any open source library or framework that can perform some basic validation and escaping functionality for a MySQL Db. i envisage something along the lines of: //give it something to perform the quote() quoteInto() methods $lib->setSanitizor($MyZend_DBAdaptor); //tell it structure of the table - colnames/coltypes/ etc $lib->setTableDescription($tableDescArray); //use it to validate and escape according to coltype foreach ($prospectiveData as $colName => $rawValue) if ( $lib->isValid($colName, $rawValue)) { //add it to the set clause $setValuesArray[$lib->escapeIdentifier($colName);] = $lib->getEscapedValue($colName,$rawValue); } else { throw new Exception($colName->getErrorMessage()); } etc... I have looked into - Zend_Db_Table (which knows about a table's description), and - Zend_Db_Adaptor (which knows how to escape/sanitize values depending on TYPE) but they do not automatically do any clever stuff during updates/inserts Anyone know of a good PHP library to preform this kind of validation that I could use rather than writing my own? i envisage alot of this kind of stuff: ... elseif (eregi('^INT|^INTEGER',$dataset_element_arr[col_type])) { $datatype='int'; if (eregi('unsigned',$dataset_element_arr[col_type])) { $int_max_val=4294967296; $int_min_val=0; } else { $int_max_val=2147483647; $int_min_val=-2147483648; } } (p.s I know eregi is deprecated - its just an example of laborious code)

    Read the article

  • Insert a list of objects using MyBatis 3

    - by T Soares
    I've tried to insert a list in a database but I've got some the error: org.springframework.jdbc.BadSqlGrammarException: SqlSession operation; bad SQL grammar []; nested exception is java.sql.SQLException: ORA-00913: too many values (...). The code that I've used: <insert id="insertListMyObject" parameterType="java.util.List" > INSERT INTO my_table (ID_ITEM, ATT1, ATT2) VALUES <foreach collection="list" item="item" index="index" open="(" close=")" separator=","> #{item.idItem, jdbcType=BIGINT}, #{item.att1, jdbcType=INTEGER}, #{item.att2, jdbcType=STRING} </foreach> </insert> My dao cals the method: SqlSessionTemplate().insert(MAPPER+".insertListMyObject", parameterList); Where the parameterList is: List<MyObjects>. Does someone have a clue about what's this error? Or if does exists a better way to do multiples inserts operation. Many thanks!

    Read the article

  • IEnumerable.Cast<>

    - by Renato Person
    If I can implicitly cast an integer value to a double (and vice versa), like: int a = 4; double b = a; // now b holds 4.0 Why can I not do this: int[] intNumbers = {10, 6, 1, 9}; double[] doubleNumbers2 = intNumbers.Cast<double>().ToArray<double>(); I get an "Specified cast is not valid" error message. Doing the opposite (casting from double to int) results in the same error. What am I doing wrong?

    Read the article

  • Custom View embed in Gallery crashes while key press

    - by tao
    Hi there, I'd like to find some stuff to replace the Tab component, so I'd make a custom View named StringView, which has the ability to display text, and to embed it into a Gallery. But it always crashes with error "NullPointerException at InputMethodManager". I have no idea about this, any help&tip&suggest are appreciate. Detail of my issue: First I'd created a class StringView extends View: public class StringView extends View { protected final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); protected String mString; protected int mAscent; // Constructor public StringView(Context context, String string) { super(context); mPaint.setARGB(255, 255, 60, 10); mPaint.setTextSize(30); //mPaint.setFakeBoldText(true); mString = string; setPadding(20,15,20,15); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); int w = this.getPaddingLeft(); int h = this.getPaddingTop() - mAscent; canvas.drawText(mString, w, h, mPaint); } public void setString(String str) { mString = str; this.requestLayout(); this.invalidate(); } public String getString() { return mString; } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { setMeasuredDimension(measureWidth(widthMeasureSpec), measureHeight(heightMeasureSpec)); } /** * Determines the width of this view * @param measureSpec A measureSpec packed into an int * @return The width of the view, honoring constraints from measureSpec */ private int measureWidth(int measureSpec) { int result = 0; int specMode = MeasureSpec.getMode(measureSpec); int specSize = MeasureSpec.getSize(measureSpec); if (specMode == MeasureSpec.EXACTLY) { // We were told how big to be result = specSize; } else { // Measure the text result = (int) mPaint.measureText(mString) + getPaddingLeft() + getPaddingRight(); if (specMode == MeasureSpec.AT_MOST) { // Respect AT_MOST value if that was what is called for by measureSpec result = Math.min(result, specSize); } } return result; } /** * Determines the height of this view * @param measureSpec A measureSpec packed into an int * @return The height of the view, honoring constraints from measureSpec */ private int measureHeight(int measureSpec) { int result = 0; int specMode = MeasureSpec.getMode(measureSpec); int specSize = MeasureSpec.getSize(measureSpec); mAscent = (int) mPaint.ascent(); if (specMode == MeasureSpec.EXACTLY) { // We were told how big to be result = specSize; } else { // Measure the text (beware: ascent is a negative number) result = (int) (-mAscent + mPaint.descent()) + getPaddingTop() + getPaddingBottom(); if (specMode == MeasureSpec.AT_MOST) { // Respect AT_MOST value if that was what is called for by measureSpec result = Math.min(result, specSize); } } return result; } } Second I put it in to Gallery through Adapter Gallery gallery = (Gallery) findViewById(R.id.gallery); gallery.setAdapter(new ImageAdapter(this)); ImageAdapter: public class ImageAdapter extends BaseAdapter { int mGalleryItemBackground; private Context mContext; private View[] mImages = genSerielImageViews(); public ImageAdapter(Context c) { mContext = c; TypedArray a = obtainStyledAttributes(R.styleable.Gallery); mGalleryItemBackground = a.getResourceId( R.styleable.Gallery_android_galleryItemBackground, 0); a.recycle(); } private View[] genSerielImageViews() { if (true) { int N = 6; StringView[] views = new StringView[N]; for (int i=0; i<N; i++) { views[i] = new StringView(mContext, "ITEM #" + Integer.toString(i) ); } return views; } else { int N = 6; TextView[] views = new TextView[N]; for (int i=0; i<N; i++) { views[i] = new TextView( mContext ); views[i].setText("CCTV #" + Integer.toString(i) ); } return views; } } public int getCount() { return mImages.length; } public Object getItem(int position) { return position; } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { return mImages[position]; } } Then Compile&Run, press keypad RIGHT and I got a crash, It's turns out a weird InputMethodManager error: 03-18 07:22:33.568: ERROR/AndroidRuntime(958): Uncaught handler: thread main exiting due to uncaught exception 03-18 07:22:33.648: ERROR/AndroidRuntime(958): java.lang.NullPointerException 03-18 07:22:33.648: ERROR/AndroidRuntime(958): at android.view.inputmethod.InputMethodManager.startInputInner(InputMethodManager.java:940) 03-18 07:22:33.648: ERROR/AndroidRuntime(958): at android.view.inputmethod.InputMethodManager.checkFocus(InputMethodManager.java:1114) 03-18 07:22:33.648: ERROR/AndroidRuntime(958): at android.view.ViewRoot.handleMessage(ViewRoot.java:1869) 03-18 07:22:33.648: ERROR/AndroidRuntime(958): at android.os.Handler.dispatchMessage(Handler.java:99) 03-18 07:22:33.648: ERROR/AndroidRuntime(958): at android.os.Looper.loop(Looper.java:123) 03-18 07:22:33.648: ERROR/AndroidRuntime(958): at android.app.ActivityThread.main(ActivityThread.java:4310) 03-18 07:22:33.648: ERROR/AndroidRuntime(958): at java.lang.reflect.Method.invokeNative(Native Method) 03-18 07:22:33.648: ERROR/AndroidRuntime(958): at java.lang.reflect.Method.invoke(Method.java:521) 03-18 07:22:33.648: ERROR/AndroidRuntime(958): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860) 03-18 07:22:33.648: ERROR/AndroidRuntime(958): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 03-18 07:22:33.648: ERROR/AndroidRuntime(958): at dalvik.system.NativeStart.main(Native Method) Thanks.

    Read the article

  • Enum in Hibernate, persisting as an enum

    - by niklassaers
    In my MySQL database, there's the column "gender enum('male','female')" I've created my enum "com.mydomain.myapp.enums.Gender", and in my Person entity I'm defined "Gender gender". Now I'd want to keep the enum type in my MySQL database, but when I launch my application I get: Wrong column type in MyApp.Person for column Gender. Found: enum, expected: integer Why is this? This would be the equivalent as if I'd annotated my "Gender gender" with "@Enumerated(EnumType.ORDINAL)", which I haven't. EnumType seems only to be able to be either ORDINAL or STRING, so how do I specify that it should treat the field as an enum, not as an int? (not that there's much difference, but enough for it to get upset about it.)

    Read the article

  • Querying a Single Column with LINQ

    - by Hossein Margani
    Hi Every one! I want to fetch array of values of a single column in a table, for example, I have a table named Customer(ID,Name), and want to fetch ids of all customers. my query in LINQ is: var ids = db.Customers.Select(c=>c.ID).ToList(); The answer of this query is correct, but I ran SQL Server Profiler, and saw the query which was like this: SELECT [t0].[ID], [t0].[Name] FROM [dbo].[Customer] AS [t0] I understood that LINQ selects all columns and then creates the integer array of ID fields. How can I write a LINQ query which generates this query in SQL Server: SELECT [t0].[ID] FROM [dbo].[Customer] AS [t0] Thank you.

    Read the article

  • Why is this an invalid Turing machine?

    - by Danny King
    Whilst doing exam revision I am having trouble answering the following question from the book, "An Introduction to the Theory of Computation" by Sipser. Unfortunately there's no solution to this question in the book. Explain why the following is not a legitimate Turing machine. M = { The input is a polynomial p over variables x1, ..., xn Try all possible settings of x1, ..., xn to integer values Evaluate p on all of these settings If any of these settings evaluates to 0, accept; otherwise reject. } This is driving me crazy! I suspect it is because the set of integers is infinite? Does this somehow exceed the alphabet's allowable size? Thanks!

    Read the article

  • What is the length of time to send a list of 200,000 integers from a client's browser to an internet

    - by indiehacker
    Over the connections that most people in the USA have in their homes, what is the approximate length of time to send a list of 200,000 integers from a client's browser to an internet sever (say Google app engine)? Does it change much if the data is sent from an iPhone? How does the length of time increase as the size of the integer list increases (say with a list of a million integers) ? Context: I wasn't sure if I should write code to do some simple computations and sorting of such lists for the browser in javascript or for the server in python, so I wanted to explore this issue of how long it takes to send the output data from a browser to a server over the web in order to help me decide where (client's browser or app engine server) is the best place for such computations to be processed.

    Read the article

  • Display a gallery of images that are stored as Drawables in a List

    - by Tyler
    Hello - I am trying to modify this example: http://developer.android.com/resources/tutorials/views/hello-gridview.html But instead of displaying images that are resources, I want to display Drawables that I currently am storing in a List. Can anyone instruct me on how I would modify private Integer[] mThumbIds = { R.drawable.sample_2, R.drawable.sample_3, R.drawable.sample_4, R.drawable.sample_5, R.drawable.sample_6, R.drawable.sample_7, R.drawable.sample_0, R.drawable.sample_1, R.drawable.sample_2, R.drawable.sample_3, R.drawable.sample_4, R.drawable.sample_5, R.drawable.sample_6, R.drawable.sample_7, R.drawable.sample_0, R.drawable.sample_1, R.drawable.sample_2, R.drawable.sample_3, R.drawable.sample_4, R.drawable.sample_5, R.drawable.sample_6, R.drawable.sample_7 }; To display my drawable items instead? Thanks!

    Read the article

  • Why is it bad to use boolean flags in databases? And what should be used instead?

    - by David Chanin
    I've been reading through some of guides on database optimization and best practices and a lot of them suggest not using boolean flags at all in the DB schema (ex http://forge.mysql.com/wiki/Top10SQLPerformanceTips). However, they never provide any reason as to why this is bad. Is it a peformance issue? is it hard to index or query properly? Furthermore, if boolean flags are bad, what should you use to store boolean values in a database? Is it better to store boolean flags as an integer and use a bitmask? This seems like it would be less readable.

    Read the article

  • Implementing parts of rfc4226 (HOTP) in mysql

    - by Moose Morals
    Like the title says, I'm trying to implement the programmatic parts of RFC4226 "HOTP: An HMAC-Based One-Time Password Algorithm" in SQL. I think I've got a version that works (in that for a small test sample, it produces the same result as the Java version in the code), but it contains a nested pair of hex(unhex()) calls, which I feel can be done better. I am constrained by a) needing to do this algorithm, and b) needing to do it in mysql, otherwise I'm happy to look at other ways of doing this. What I've got so far: -- From the inside out... -- Concatinate the users secret, and the number of time its been used -- find the SHA1 hash of that string -- Turn a 40 byte hex encoding into a 20 byte binary string -- keep the first 4 bytes -- turn those back into a hex represnetation -- convert that into an integer -- Throw away the most-significant bit (solves signed/unsigned problems) -- Truncate to 6 digits -- store into otp -- from the otpsecrets table select (conv(hex(substr(unhex(sha1(concat(secret, uses))), 1, 4)), 16, 10) & 0x7fffffff) % 1000000 into otp from otpsecrets; Is there a better (more efficient) way of doing this?

    Read the article

  • How to make Databinding type safe and support refactoring

    - by Ian Ringrose
    When I wish to bind a control to a property of my object, I have to provide the name of the property as a string. This is not very good because: If the property is removed or renamed, I don’t get a compiler warning. If a rename the property with a refactoring tool, it is likely the data binding will not be updated. I don’t get an error until runtime if the type of the property is wrong, e.g. binding an integer to a date chooser. Is there a design-paten that gets round this, but still has the ease of use of data-binding? (This is a problem in WinForm, Asp.net and WPF and most likely lots of other systems) I have now found "workarounds for nameof() operator in C#: typesafe databinding" that also has a good starting point for a solution.

    Read the article

  • Automating Visual Studio 2010 from a console app

    - by JoelFan
    I am trying to run the following code (which I got from here). The code just creates a new "Output" pane in Visual Studio and writes a few lines to it. Public Sub WriteToMyNewPane() Dim win As Window = _ DTE.Windows.Item(EnvDTE.Constants.vsWindowKindOutput) Dim ow As OutputWindow = win.Object Dim owPane As OutputWindowPane Dim cnt As Integer = ow.OutputWindowPanes.Count owPane = ow.OutputWindowPanes.Add("My New Output Pane") owPane.Activate() owPane.OutputString("My text1" & vbCrLf) owPane.OutputString("My text2" & vbCrLf) owPane.OutputString("My text3" & vbCrLf) End Sub Instead of running it as a Macro, I want to run it as an independent console application that connects to a currently running instance of Visual Studio 2010. I'm having a hard time figuring out how to set the value of DTE. I think I may need to call GetActiveObject, but I'm not sure how. Any pointers?

    Read the article

  • How to write to a varchar(max) column using ODBC

    - by andyjohnson
    Summary: I'm trying to write a text string to a column of type varchar(max) using ODBC and SQL Server 2005. It fails if the length of the string is greater than 8000. Help! I have some C++ code that uses ODBC (SQL Native Client) to write a text string to a table. If I change the column from, say, varchar(100) to varchar(max) and try to write a string with length greater than 8000, the write fails with the following error [Microsoft][ODBC SQL Server Driver]String data, right truncation So, can anyone advise me on if this can be done, and how? Some example (not production) code that shows what I'm trying to do: SQLHENV hEnv = NULL; SQLRETURN iError = SQLAllocEnv(&hEnv); HDBC hDbc = NULL; SQLAllocConnect(hEnv, &hDbc); const char* pszConnStr = "Driver={SQL Server};Server=127.0.0.1;Database=MyTestDB"; UCHAR szConnectOut[SQL_MAX_MESSAGE_LENGTH]; SWORD iConnectOutLen = 0; iError = SQLDriverConnect(hDbc, NULL, (unsigned char*)pszConnStr, SQL_NTS, szConnectOut, (SQL_MAX_MESSAGE_LENGTH-1), &iConnectOutLen, SQL_DRIVER_COMPLETE); HSTMT hStmt = NULL; iError = SQLAllocStmt(hDbc, &hStmt); const char* pszSQL = "INSERT INTO MyTestTable (LongStr) VALUES (?)"; iError = SQLPrepare(hStmt, (SQLCHAR*)pszSQL, SQL_NTS); char* pszBigString = AllocBigString(8001); iError = SQLSetParam(hStmt, 1, SQL_C_CHAR, SQL_VARCHAR, 0, 0, (SQLPOINTER)pszBigString, NULL); iError = SQLExecute(hStmt); // Returns SQL_ERROR if pszBigString len > 8000 The table MyTestTable contains a single colum defined as varchar(max). The function AllocBigString (not shown) creates a string of arbitrary length. I understand that previous versions of SQL Server had an 8000 character limit to varchars, but not why is this happening in SQL 2005? Thanks, Andy

    Read the article

  • How to prevent "Local transaction already has 1 non-XA Resource" exception?

    - by Zeratul
    Hi, I'm using 2 PU in stateless EJB and each of them is invoked on one method: @PersistenceContext(unitName="PU") private EntityManager em; @PersistenceContext(unitName="PU2") private EntityManager em2; @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW ) public void getCandidates(final Integer eventId) throws ControllerException { ElectionEvent electionEvent = em.find(ElectionEvent.class, eventId); ... Person person = getPerson(candidate.getLogin()); ... } @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW ) private Person getPerson(String login) throws ControllerException { Person person = em2.find(Person.class, login); return person; } Those methods are annotated with REQUIRES_NEW transcaction to avoid this exception. When I was calling these method from javaFX applet, all worked as expected. Now I'm trying to call them from JAX-RS webservice (I don't see any logical difference as in both cases ejb was looked up in initial context) and I keep getting this exception. When I set up XADatasource in glassfish 2.1 connection pools, I got nullpointer exception on em2. Any ideas what to try next? Regards

    Read the article

  • Convert C# event handling to VB.NET

    - by Quandary
    Question: The following C# code: public event RemoteAPI.NotifyCallback Notify { add { s_notify = value; } remove { Console.WriteLine("TODO : Notify remove."); } } How do I convert this to VB.NET ? It implements an interface: Public Interface ICallsToServer ''' <summary> ''' Function to call the server from the client ''' </summary> ''' <param name="n">Some number</param> ''' <returns>Some interesting text</returns> Function SomeSimpleFunction(ByVal n As Integer) As String ''' <summary> ''' Add or remove callback destinations on the client ''' </summary> Event Notify As NotifyCallback End Interface The VB.NET automatically generated code was: Public Event Notify(ByVal s As String) Implements RemoteAPI.ICallsToServer.Notify

    Read the article

  • Yet another date formatting problem :(

    - by Jonesy
    Hi folks, I seem to have a date formatting problem every day! I am querying a table and am getting a date back in the format dd/mm/yyyy (as a string btw). Brilliant! thats what I want. But, now I want to convert that string to a date so i can do dim dayNumber as integer = day.DayOfWeek But when I convert it to a date it changes it to #m/dd/yyyy#. AHHHH! how can I change this? Cheers

    Read the article

  • I have a having a a matrix index bounds in matlab

    - by Ben Fossen
    I keep getting the error( this is in Matlab) Attempted to access r(0,0); index must be a positive integer or logical. Error in == Romberg at 15 I ran it with Romberg(1.3, 2.19,8) I think the problem is the statment is not logical because I made it positive and still got the same error. anyone got some ideas of what i could do? function Romberg(a, b, n) h = b - a; r = zeros(n,n); for i = 1:n h = h/2; sum1 = 0; for k = 1:2:2^(i) sum1 = sum1 + f(a + k*h); end r(i,0) = (1/2)*r(i-1,0) + (sum1)*h; for j = 1:i r(i,j) = r(i,j-1) + (r(i,j-1) - r(i-1,j-1))/((4^j) - 1); end end disp(r); end function f_of_x = f(x) f_of_x = sin(x)/x; end

    Read the article

  • Hibernate Subquery and DetachedCriteria

    - by dawez
    I have created a DetachedCriteria that is retrieving estates that have the isApproved and isPublished set to true. It is defined in this way: DetachedCriteria activePublishedCriteria = DetachedCriteria.forClass(Estate.class) .add(Restrictions.eq("isApproved", true)) .add(Restrictions.eq("isPublished", true)) .setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY); I would like to reuse this criteria in some of the queries. In this case I would like to replace the isApproved and isPublished restrictions with the DetachedCriteria Criteria criteria = getSession().createCriteria(Estate.class) .createAlias("city", "c") .add(Restrictions.eq("c.id", cityID)) // the following 2 lines should be use the DetachedCriteria .add(Restrictions.eq("isApproved", true)) .add(Restrictions.eq("isPublished", true)) .setProjection(Projections.rowCount()); return (Integer) criteria.list().get(0); Is there a way to do this ? Tried to use .add.Subqueries.geAll(.... But cannot make it work properly. I could not find proper documentation on the Subqueries in Hibernate. Tips are welcomed.

    Read the article

  • Round prices up to nearest 5 after conversion in oscommerce

    - by Rhyso
    Hi there, A conversion question relating to prices in oscommerce: I am needing for a custom currency conversion to round the USD prices up to the nearest 5$ to avoid prices being displayed at silly prices such as $263. I am trying to convert to an int and round the following line : $curr-display_price($listing['products_price'], tep_get_tax_rate($listing['products_tax_class_id'])); ( as for some reason the price is displayed as a string, im guessing to include the currency sign) However not having much luck. Does anybody know where the root conversion takes place as it might be easier for me to round() or ceil() from there when it is a raw integer Or any other ideas of how I can round the conversion? Thanks for any help Rhys Thomas

    Read the article

  • How to determine the data type of a CvMat

    - by Chris
    When using the CvMat type, the type of data is crucial to keeping your program running. For example, depending on whether your data is type float or unsigned char, you would choose one of these two commands: cvmGet(mat, row, col); cvGetReal2D(mat, row, col); Is there a universal approach to this? If the wrong data type matrix is passed to these calls, they crash at runtime. This is becoming an issue, since a function I have defined is getting passed several different types of matrices. How do you determine the data type of a matrix so you can always access its data? I tried using the "type()" function as such. CvMat* tmp_ptr = cvCreateMat(t_height,t_width,CV_8U); std::cout << "type = " << tmp_ptr->type() << std::endl; This does not compile, saying "term does not evaluate to a function taking 0 arguments". If I remove the brackets after the word type, I get a type of 1111638032 EDIT minimal application that reproduces this... int main( int argc, char** argv ) { CvMat *tmp2 = cvCreateMat(10,10, CV_32FC1); std::cout << "tmp2 type = " << tmp2->type << " and CV_32FC1 = " << CV_32FC1 << " and " << (tmp2->type == CV_32FC1) << std::endl; } Output: tmp2 type = 1111638021 and CV_32FC1 = 5 and 0

    Read the article

  • mysql fulltext search as level2 index

    - by Nir
    lets say I have a table with product details. one of the fields is category (integer). I want to do fulltext search on product name in specific category. Unfortunately Mysql does not allow me to specify index that includes category and product name as fulltext. It looks like I can use fulltext only on product_name and theefore any fulltext search will search product names in all categories. Is there any way to solve this (allow fulltext search/index only on products in category)?

    Read the article

  • Unable to reverse seemingly simple rails migration - getting "altered_table.column may not be NULL"

    - by brad
    I have a table 'invoices' in my development database (sqlite3) populated with a small amount of test data. I wanted to add a column 'invoice_number' to it and set up a migration like so: class AddInvoiceNumberColumnToInvoices < ActiveRecord::Migration def self.up add_column :invoices, :invoice_number, :integer end def self.down remove_column :invoices, :invoice_number end end I ran rake db:migrate and it seemed to migrate just fine. However, when I tried to access this column through ActiveRecord it didn't seem to be there. I decided to undo this migration and try again (not sure what I was going to try but I thought I'd start by undoing it) with rake db:migrate VERSION='whatever_the_migration_before_this_one_was_called'. This failed with the error message == AddInvoiceNumberColumnToInvoices: reverting =============================== -- remove_column(:invoices, :invoice_number) rake aborted! An error has occurred, this and all later migrations canceled: altered_invoices.invoice_number may not be NULL I can't find any documentation of this error. Is anyone able to explain what I have done wrong, and more importantly how I can fix this?

    Read the article

  • How to use derived class shared variables in shared methods of base class

    - by KoolKabin
    Hi guys, I am trying to add shared members in derived classes and use that values in base classes... I have base class DBLayer public shared function GetDetail(byval UIN as integer) dim StrSql = string.format("select * from {0} where uin = {1}", tablename, uin) .... end function end class my derived class class User inherits dblayer public shared tabledname as string = "users" end class class item inherits dblayer public shared tabledname as string = "item" end class class category inherits dblayer public shared tabledname as string = "category" end class currently there is error using the tablename variable of derived class in base class but i want to use it... coz i dun know other techniques... if other solutions are better then u can post it or u can say how can i make it work? confused...

    Read the article

  • improving conversions to binary and back in C#

    - by Saad Imran.
    I'm trying to write a general purpose socket server for a game I'm working on. I know I could very well use already built servers like SmartFox and Photon, but I wan't to go through the pain of creating one myself for learning purposes. I've come up with a BSON inspired protocol to convert the the basic data types, their arrays, and a special GSObject to binary and arrange them in a way so that it can be put back together into object form on the client end. At the core, the conversion methods utilize the .Net BitConverter class to convert the basic data types to binary. Anyways, the problem is performance, if I loop 50,000 times and convert my GSObject to binary each time it takes about 5500ms (the resulting byte[] is just 192 bytes per conversion). I think think this would be way too slow for an MMO that sends 5-10 position updates per second with a 1000 concurrent users. Yes, I know it's unlikely that a game will have a 1000 users on at the same time, but like I said earlier this is supposed to be a learning process for me, I want to go out of my way and build something that scales well and can handle at least a few thousand users. So yea, if anyone's aware of other conversion techniques or sees where I'm loosing performance I would appreciate the help. GSBitConverter.cs This is the main conversion class, it adds extension methods to main datatypes to convert to the binary format. It uses the BitConverter class to convert the base types. I've shown only the code to convert integer and integer arrays, but the rest of the method are pretty much replicas of those two, they just overload the type. public static class GSBitConverter { public static byte[] ToGSBinary(this short value) { return BitConverter.GetBytes(value); } public static byte[] ToGSBinary(this IEnumerable<short> value) { List<byte> bytes = new List<byte>(); short length = (short)value.Count(); bytes.AddRange(length.ToGSBinary()); for (int i = 0; i < length; i++) bytes.AddRange(value.ElementAt(i).ToGSBinary()); return bytes.ToArray(); } public static byte[] ToGSBinary(this bool value); public static byte[] ToGSBinary(this IEnumerable<bool> value); public static byte[] ToGSBinary(this IEnumerable<byte> value); public static byte[] ToGSBinary(this int value); public static byte[] ToGSBinary(this IEnumerable<int> value); public static byte[] ToGSBinary(this long value); public static byte[] ToGSBinary(this IEnumerable<long> value); public static byte[] ToGSBinary(this float value); public static byte[] ToGSBinary(this IEnumerable<float> value); public static byte[] ToGSBinary(this double value); public static byte[] ToGSBinary(this IEnumerable<double> value); public static byte[] ToGSBinary(this string value); public static byte[] ToGSBinary(this IEnumerable<string> value); public static string GetHexDump(this IEnumerable<byte> value); } Program.cs Here's the the object that I'm converting to binary in a loop. class Program { static void Main(string[] args) { GSObject obj = new GSObject(); obj.AttachShort("smallInt", 15); obj.AttachInt("medInt", 120700); obj.AttachLong("bigInt", 10900800700); obj.AttachDouble("doubleVal", Math.PI); obj.AttachStringArray("muppetNames", new string[] { "Kermit", "Fozzy", "Piggy", "Animal", "Gonzo" }); GSObject apple = new GSObject(); apple.AttachString("name", "Apple"); apple.AttachString("color", "red"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)1.5); GSObject lemon = new GSObject(); apple.AttachString("name", "Lemon"); apple.AttachString("color", "yellow"); apple.AttachBool("inStock", false); apple.AttachFloat("price", (float)0.8); GSObject apricoat = new GSObject(); apple.AttachString("name", "Apricoat"); apple.AttachString("color", "orange"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)1.9); GSObject kiwi = new GSObject(); apple.AttachString("name", "Kiwi"); apple.AttachString("color", "green"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)2.3); GSArray fruits = new GSArray(); fruits.AddGSObject(apple); fruits.AddGSObject(lemon); fruits.AddGSObject(apricoat); fruits.AddGSObject(kiwi); obj.AttachGSArray("fruits", fruits); Stopwatch w1 = Stopwatch.StartNew(); for (int i = 0; i < 50000; i++) { byte[] b = obj.ToGSBinary(); } w1.Stop(); Console.WriteLine(BitConverter.IsLittleEndian ? "Little Endian" : "Big Endian"); Console.WriteLine(w1.ElapsedMilliseconds + "ms"); } Here's the code for some of my other classes that are used in the code above. Most of it is repetitive. GSObject GSArray GSWrappedObject

    Read the article

< Previous Page | 166 167 168 169 170 171 172 173 174 175 176 177  | Next Page >