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  • Error in connection in ruby.

    - by piemesons
    require 'rubygems' require 'mysql' db = Mysql.connect('localhost', 'root', '', 'mohit') //db.rb:4: undefined method `connect' for Mysql:Class (NoMethodError) //undefined method `real_connect' for Mysql:Class (NoMethodError) db.query("CREATE TABLE people ( id integer primary key, name varchar(50), age integer)") db.query("INSERT INTO people (name, age) VALUES('Chris', 25)") begin query = db.query('SELECT * FROM people') puts "There were #{query.num_rows} rows returned" query.each_hash do |h| puts h.inspect end rescue puts db.errno puts db.error end error i am geting is: undefined method `connect' for Mysql:Class (NoMethodError) OR undefined method `real_connect' for Mysql:Class (NoMethodError) EDIT return value of Mysql.methods ["private_class_method", "inspect", "name", "tap", "clone", "public_methods", "object_id", "__send__", "method_defined?", "instance_variable_defined?", "equal?", "freeze", "extend", "send", "const_defined?", "methods", "ancestors", "module_eval", "instance_method", "hash", "autoload?", "dup", "to_enum", "instance_methods", "public_method_defined?", "instance_variables", "class_variable_defined?", "eql?", "constants", "id", "instance_eval", "singleton_methods", "module_exec", "const_missing", "taint", "instance_variable_get", "frozen?", "enum_for", "private_method_defined?", "public_instance_methods", "display", "instance_of?", "superclass", "method", "to_a", "included_modules", "const_get", "instance_exec", "type", "<", "protected_methods", "<=>", "class_eval", "==", "class_variables", ">", "===", "instance_variable_set", "protected_instance_methods", "protected_method_defined?", "respond_to?", "kind_of?", ">=", "public_class_method", "to_s", "<=", "const_set", "allocate", "class", "new", "private_methods", "=~", "tainted?", "__id__", "class_exec", "autoload", "untaint", "nil?", "private_instance_methods", "include?", "is_a?"] return value of Mysql.methods(false) is []... blank array

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  • Building and rendering a bitmap from a double array

    - by Ami
    I'm new to c# and I'm sure I'm missing something simple here. I'm trying to build a bitmap from integer values (0-255) in a double array and then render it in a PictureBox. I think my Bitmap is getting generated but it isn't displaying in my PictureBox. Bitmap bmp = new Bitmap(image_width, image_height); Color pxl_color = new Color(); for (int i = 0; i < image_width; i++) { for (int j = 0; j < image_height; j++) { pxl_color = Color.FromArgb(array_bitmap[i][j]); bmp.SetPixel(i, j, pxl_color); } } PictureBox1.Image = bmp; Thanks in advance.

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  • Background Image w/Quartz Drawing

    - by James
    I'm using Quartz to do some basic drawing. I recently decided I wanted a background image for my app. So I went into my XIB file and added a UIImageView and set the background, looks good. However, when I run it, the Z-Index of the image is above my drawing. I googled a bit and found that you can do Layout Send to Back in IB...but that option is grayed out to me when I have my UIImageView selected. Is there an easy way to move this UIImageView permanently to the background? Is there perhaps an alternate method to doing this that I should consider? Thanks

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  • C++: Cannot convert from foo& to foo*

    - by Rosarch
    I have a method: odp(foo& bar); I'm trying to call it: foo baz; odp(&baz); I get a compiler error: error C2664: "odp" cannot convert parameter 1 from 'foo *' to 'foo &' What am I doing wrong? Aren't I passing in a reference to baz? UPDATE: Perhaps I have a misconception about the relationship between pointers and references. I thought that they were the same, except references couldn't be null. Is that incorrect?

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  • How to sanely read and dump structs to disk when some fields are pointers?

    - by bp
    Hello, I'm writing a FUSE plugin in C. I'm keeping track of data structures in the filesystem through structs like: typedef struct { block_number_t inode; filename_t filename; //char[SOME_SIZE] some_other_field_t other_field; } fs_directory_table_item_t; Obviously, I have to read (write) these structs from (to) disk at some point. I could treat the struct as a sequence of bytes and do something like this: read(disk_fd, directory_table_item, sizeof(fs_directory_table_item_t)); ...except that cannot possibly work as filename is actually a pointer to the char array. I'd really like to avoid having to write code like: read(disk_df, *directory_table_item.inode, sizeof(block_number_t)); read(disk_df, directory_table_item.filename, sizeof(filename_t)); read(disk_df, *directory_table_item.other_field, sizeof(some_other_field_t)); ...for each struct in the code, because I'd have to replicate code and changes in no less than three different places (definition, reading, writing). Any DRYer but still maintainable ideas?

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  • Java cannot find symbol enum

    - by JDelage
    Hi, I'm modeling a chess game on Java, and I'm having some problem. Here's what the code looks like (the relevant parts): Enum class Couleur.java: public enum Couleur {BLANC, NOIR} Piece.java: public abstract class Piece { (...) public Piece(Couleur couleurParam){ this.couleurPiece = couleurParam; } (...) } And finally Tour.java: public class Tour extends Piece { (...) public Tour(Couleur couleurParam){ super(couleurParam); } (...) } All the .java files are in the same folder. Yet at compile I get a "cannot find symbol symbol : variable NOIR location: class Plateau" (Plateau is the class that instantiates Tour.) Can anyone help me figure out what's wrong here? Many thanks, JDelage

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  • Right rotate of tree in Haskell: how is it work?

    - by Roman
    I don't know haskell syntax, but I know some FP concepts (like algebraic data types, pattern matching, higher-order functions ect). Can someone explain please, what does this code mean: data Tree ? = Leaf ? | Fork ? (Tree ?) (Tree ?) rotateR tree = case tree of Fork q (Fork p a b) c -> Fork p a (Fork q b c) As I understand, first line is something like Tree-type declaration (but I don't understand it exactly). Second line includes pattern matching (I don't understand as well why do we need to use pattern matching here). And third line does something absolutely unreadable for non-haskell developer. I've found definition of Fork as fork (f,g) x = (f x, g x) but I can't move further anymore.

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  • What is a really simple explanation of unit testing?

    - by ensnare
    I've never done any unit testing before, and would like to learn what it is and how it can be useful in my Python code. I've read through a few Python unit testing tutorials online but they're all so complicated and assume an extended programming background. I'm using Python with Pylons to create a simple web app. Any simple examples would be greatly appreciated. Thanks!

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  • Java: how to have global values inside a class?

    - by HH
    I want less methods. I want a common global TestClass from which I could use any of its value inside the class. import java.util.*; import java.io.*; public class TestClass { TestClass(String hello){ String hallo = hello; String halloSecond = "Saluto!"; } public static void main(String[] args) { TestClass test = new TestClass("Tjena!"); System.out.println("I want "Tjena!": " + test.hallo); TestClass testSecond = new TestClass("1"); System.out.println("I want Saluto!:" + test.halloSecond); System.out.println("I want Saluto!:" + testSecond.halloSecond); // How can I get glob.vars like the "Saluto!"? } }

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  • Question about Radio button/PHP/MySQL

    - by Marcelo
    Hi, I'm an engineering student and I'm developing a simple software based on HTML, PHP and mysql. I learned this topics on w3schools. I know only the basics. I tried to search about this in this website but I found questions about PHP, MySQL and HTML radio buttons which were much more complex than I need and that I could understand. Sorry for the English. (Q1) Ex: $email=$_REQUEST['email'] , in this case the input is text, if it where like a radio button for ex: sex: male or female, how would it be? (Q2) what would be the type of this field (for exemple sex in question 1) in the database: text, int, varchar ? Thanks for the attention

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  • Why won't the following haskell code compile?

    - by voxcogitatio
    I'm in the process of writing a small lisp interpreter in haskell. In the process i defined this datatype, to get a less typed number; data Number = _Int Integer | _Rational Rational | _Float Double deriving(Eq,Show) Compiling this fails with the following error: ERROR "types.hs":16 - Syntax error in data type declaration (unexpected `|') Line 16 is the line w. the first '|' in the code above.

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  • [Python] OR in regular expression?

    - by www.yegorov-p.ru
    Hello. I have text file with several thousands lines. I want to parse this file into database and decided to write a regexp. Here's part of file: blablabla checked=12 unchecked=1 blablabla unchecked=13 blablabla checked=14 As a result, I would like to get something like (12,1) (0,13) (14,0) Is it possible?

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  • Another dynamic memory allocation bug.

    - by m4design
    I'm trying to allocate memory for a multidimensional array (8 rows, 3 columns). Here's the code for the allocation (I'm sure the error is clear for you) char **ptr = (char **) malloc( sizeof(char) * 8); for (i = 0; i < 3; i++) ptr[i] = (char *) malloc( sizeof(char) * 3); The crash happens when I reference this: ptr[3][0]; Unhandled exception at 0x0135144d in xxxx.exe: 0xC0000005: Access violation writing location 0xabababab. Are there any recommended references/readings for this kind of subject? Thanks.

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  • run multiple programs in linux

    - by Betamoo
    I am trying to write a .sh file that runs many programs simultaneously I tried this prog1 prog2 But that runs prog1 then waits until prog1 ends and then starts prog2... So how can I run them in parallel? Thanks

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  • vector related memory allocation question

    - by memC
    hi all, I am encountering the following bug. I have a class Foo . Instances of this class are stored in a std::vector vec of class B. in class Foo, I am creating an instance of class A by allocating memory using new and deleting that object in ~Foo(). the code compiles, but I get a crash at the runtime. If I disable delete my_a from desstructor of class Foo. The code runs fine (but there is going to be a memory leak). Could someone please explain what is going wrong here and suggest a fix? thank you! class A{ public: A(int val); ~A(){}; int val_a; }; A::A(int val){ val_a = val; }; class Foo { public: Foo(); ~Foo(); void createA(); A* my_a; }; Foo::Foo(){ createA(); }; void Foo::createA(){ my_a = new A(20); }; Foo::~Foo(){ delete my_a; }; class B { public: vector<Foo> vec; void createFoo(); B(){}; ~B(){}; }; void B::createFoo(){ vec.push_back(Foo()); }; int main(){ B b; int i =0; for (i = 0; i < 5; i ++){ std::cout<<"\n creating Foo"; b.createFoo(); std::cout<<"\n Foo created"; } std::cout<<"\nDone with Foo creation"; std::cout << "\nPress RETURN to continue..."; std::cin.get(); return 0; }

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  • Unexpected behaviour of Order by clause

    - by Newbie
    I have a table which looks like Col1 col2 col3 col4 col5 1 5 1 4 6 1 4 0 3 7 0 1 5 6 3 1 8 2 1 5 4 3 2 1 4 The script is declare @t table(col1 int, col2 int, col3 int,col4 int,col5 int) insert into @t select 1,5,1,4,6 union all select 1,4,0,3,7 union all select 0,1,5,6,3 union all select 1,8,2,1,5 union all select 4,3,2,1,4 If I do a sorting (ascending), the output is Col1 col2 col3 col4 col5 0 1 5 6 3 1 4 0 3 7 1 5 1 4 6 1 8 2 1 5 4 3 2 1 4 The query is Select * from @t order by col1,col2,col3,col4,col5 But as can be seen that the sorting output is wrong (col2 to col5). I want the output to be every column being sorted in ascending order i.e. Col1 col2 col3 col4 col5 0 1 0 1 3 1 3 1 1 4 1 4 2 3 5 1 5 2 4 6 4 8 5 6 7 Why so and how to overcome this? Thanks in advance

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  • database connection OK,result not appear

    - by klox
    hi..all.for now i'm already connected to database but the result not appear at Tuner range is"+res+"this is my code: var str=data[0]; var matches=str.match(/[EE|EJU].*D/i); $.ajax({ type:"post", url:"process1.php", data:"tversion="+matches+"&action=tunermatches", cache:false, async:false, success: function(res){ $('#value').replacewith("<div id='value'><h6>Tuner range is"+res+".</h6></div>"); } }); }); and this is my process file: //connect to database $dbc=mysql_connect(_SRV,_ACCID,_PWD) or die(_ERROR15.": ".mysql_error()); $db=mysql_select_db("qdbase",$dbc) or die(_ERROR17.": ".mysql_error()); switch(postVar('action')) { case 'tunermatches' : tunermatches(postVar('tversion')); break; function tunermatches($tversion)){ $Tuner=mysql_real_escape_string($tversion); $sql= "SELECT remark FROM settingdata WHERE itemname='Tuner_range' AND itemdata='".$Tunermatches."'"; $res=mysql_query($sql) or die (_ERROR26.":".mysql_error()); $dat=mysql_fetch_array($res,MYSQL_NUM); if($dat[0]>0) { echo $dat[0]; } mysql_close($dbc); }

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  • Does everything after my try statement have to be encompassed in that try statement to access variab

    - by Mithrax
    I'm learning java and one thing I've found that I don't like, is generally when I have code like this: import java.util.*; import java.io.*; public class GraphProblem { public static void main(String[] args) { if (args.length < 2) { System.out.println("Error: Please specify a graph file!"); return; } FileReader in = new FileReader(args[1]); Scanner input = new Scanner(in); int size = input.nextInt(); WeightedGraph graph = new WeightedGraph(size); for(int i = 0; i < size; i++) { graph.setLabel(i,Character.toString((char)('A' + i))); } for(int i = 0; i < size; i++) { for(int j = 0; j < size; j++) { graph.addEdge(i, j, input.nextInt()); } } // .. lots more code } } I have an uncaught exception around my FileReader. So, I have to wrap it in a try-catch to catch that specific exception. My question is does that try { } have to encompass everything after that in my method that wants to use either my FileReader (in) or my Scanner (input)? If I don't wrap the whole remainder of the program in that try statement, then anything outside of it can't access the in/input because it may of not been initialized or has been initialized outside of its scope. So I can't isolate the try-catch to just say the portion that intializes the FileReader and close the try statement immediately after that. So, is it the "best practice" to have the try statement wrapping all portions of the code that are going to access variables initialized in it? Thanks!

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  • Should I invest time in learning Java language these days? (question from a greenhorn)

    - by dave-keiture
    Hi experts, Assuming you've already had a chance to look through the lambda syntax proposed for Java7 (and the other things that have happened with Java, after Oracle has bought Sun + obvious problems in Java Community Process), what do you think is the future of Java language? Should I, as a Java greenhorn, invest time in learning Java language (not talking about the core JVM, which definitely will survive anything, and worth investments), or concentrate on Scala, Groovy, or other hybrid languages on the JVM platform (I've came into Java world from PHP/Ruby). Thanks in advance.

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  • Get absolute (base) url in sinatra.

    - by berkes
    Right now, I do a get '/' do set :base_url, "#{request.env['rack.url_scheme']}://#{request.env['HTTP_HOST']}" # ... haml :index end to be able to use options.base_url in the HAML index.haml. But I am sure there is a far better, DRY, way of doing this. Yet I cannot see, nor find it. (I am new to Sinatra :)) Somehow, outside of get, I don't have request.env available, or so it seems. So putting it in an include did not work. How do you get your base url?

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  • Java method: retrieve the inheriting type

    - by DrDro
    I have several classes that extend C and I would need a method that accepts any argument of type C. But in this method I would like to know if I'm dealing with A or B. * public A extends C public B extends C public void goForIt(C c)() If I cast how can I retrieve the type in a clean way (I just read using getClass or instanceof is often not the best way). *Sorry but I can't type closing braces

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