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  • Strange behavior with large Object Types

    - by Peter Lang
    I recognized that calling a method on an Oracle Object Type takes longer when the instance gets bigger. The code below just adds rows to a collection stored in the Object Type and calls the empty dummy-procedure in the loop. Calls are taking longer when more rows are in the collection. When I just remove the call to dummy, performance is much better (the collection still contains the same number of records): Calling dummy: Not calling dummy: 11 0 81 0 158 0 Code to reproduce: Create Type t_tab Is Table Of VARCHAR2(10000); Create Type test_type As Object( tab t_tab, Member Procedure dummy ); Create Type Body test_type As Member Procedure dummy As Begin Null; --# Do nothing End dummy; End; Declare v_test_type test_type := New test_type( New t_tab() ); Procedure run_test As start_time NUMBER := dbms_utility.get_time; Begin For i In 1 .. 200 Loop v_test_Type.tab.Extend; v_test_Type.tab(v_test_Type.tab.Last) := Lpad(' ', 10000); v_test_Type.dummy(); --# Removed this line in second test End Loop; dbms_output.put_line( dbms_utility.get_time - start_time ); End run_test; Begin run_test; run_test; run_test; End; I tried with both 10g and 11g. Can anyone explain/reproduce this behavior?

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  • How to Object Array to List

    - by Peter Black
    (C#) I have 2 classes. 1 is called Employee. The other is my "main". I am trying to take a list and assign each value in list to an array of Employee object. //Inside "Main" class int counter = NameList.Count; Employee[] employee = new Employee[counter]; for (int i = 0; i <= counter; i++) { employee[i].Name = NameList[i]; employee[i].EmpNumber = EmpNumList[i]; employee[i].DateOfHire = DOHList[i]; employee[i].Salary = SalaryList[i]; employee[i].JobDescription = JobDescList[i]; employee[i].Department = DeptList[i]; } This returns the error: An unhandled exception of type 'System.NullReferenceException' occurred in Pgm4.exe Additional information: Object reference not set to an instance of an object. I think this means that I am not calling the list properly. Any help would be much appreciated. Thank you.

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  • Function Returning Negative Value

    - by Geowil
    I still have not run it through enough tests however for some reason, using certain non-negative values, this function will sometimes pass back a negative value. I have done a lot of manual testing in calculator with different values but I have yet to have it display this same behavior. I was wondering if someone would take a look at see if I am missing something. float calcPop(int popRand1, int popRand2, int popRand3, float pERand, float pSRand) { return ((((((23000 * popRand1) * popRand2) * pERand) * pSRand) * popRand3) / 8); } The variables are all contain randomly generated values: popRand1: between 1 and 30 popRand2: between 10 and 30 popRand3: between 50 and 100 pSRand: between 1 and 1000 pERand: between 1.0f and 5500.0f which is then multiplied by 0.001f before being passed to the function above Edit: Alright so after following the execution a bit more closely it is not the fault of this function directly. It produces an infinitely positive float which then flips negative when I use this code later on: pPMax = (int)pPStore; pPStore is a float that holds popCalc's return. So the question now is, how do I stop the formula from doing this? Testing even with very high values in Calculator has never displayed this behavior. Is there something in how the compiler processes the order of operations that is causing this or are my values simply just going too high? If the later I could just increase the division to 16 I think.

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  • java /TableModel of Objects/Update Object"

    - by Tomás Ó Briain
    I've a collection of Stock objects that I'm updating about 10/15 variables for in real-time. I'm accessing each Stock by its ID in the collection. I'm also trying to display this in a JTable and have implemented an AbstractTablemodel. It's not working too well. I've a RowMap that I add each ID to as Stocks are added to the TableModel. To update the prices and variables of all the stocks in the TableModel, I want to send a Stock object to an updateModel(Stock s) method. I can find the relevant row by searching the map, but how do I handle this nicely, so I don't have to start iterating through table columns and comparing the values of the cells to the variables of the object to see whether there are any differences?? Basically, i want to send a Stock object to the TableModel and update cells if there are changes and do nothing if there aren't. Any ideas about how to implement a TableModel that might do this? Any pointeres at all would be appreciated. Thanks.

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  • Fire Box doesnot support program based calling function

    - by manish
    on clicking any row of the following program... i am firinf on function mail file click....function just having alert message that shoes deffrent file name on the bases of clicking... *its working properly in IE .....FireBox N other browser function doesnot call on clicking on any row.. whats problem..please help me......i am writing code for your better awareness* For Each info In fsi Response.Write("<span id=" & " 'userijd'" & " onmouseup=" & "mailfileclick('" & info.Name & "')" & ";>") Response.Write("<td width=" & "16%" & " bgcolor=" & "#FFFFFF" & " style=" & "border-bottom-style:&nbsp;solid;&nbsp;border-bottom-width:&nbsp;1px" & " bordercolor=" & "#C0C0C0" & " nowrap" & ">") Response.Write("<font face=" & "Arial" & "style=" & "font-size:&nbsp;9pt" & " color=" & "#000000" & ">" & Mid(contents, InStr(contents, "Date: ") + Len("Date:"), 17) & "</font></td>") Response.Write("</span>") Next

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  • Passing data to a jQuery click() function

    - by jakenoble
    Hi I have a simple span like so <span class="action removeAction">Remove</span> This span is within a table, each row has a remove span. And then I call a URL using AJAX when that span is clicked. The AJAX event needs to know the ID of the object for that row? What is the best way of getting that ID into the click function? I thought I could do something like this <span class="action removeAction" id="1">Remove</span> But an ID should not start with a number? Right? Then I thought I could do <span class="action removeAction" id="my1">Remove</span> Then just strip the 'my' part from the ID, but that just seems Yuk! Below is my click event and where my AJAX event is. <script type="text/javascript" language="text/javascript"> $(document).ready(function() { $(".removeAction").click(function() { //AJAX here that needs to know the ID } }); </script> I am sure there is a nice way of doing this? Thanks. Jake.

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  • Passing functor and function pointers interchangeably using a templated method in C++

    - by metroxylon
    I currently have a templated class, with a templated method. Works great with functors, but having trouble compiling for functions. Foo.h template <typename T> class Foo { public: // Constructor, destructor, etc... template <typename Func> void bar(T x, Func f); }; template <typename T> template <typename Func> Foo::bar(T x, Func f) { /* some code here */ } Main.cpp #include "Foo.h" template <typename T> class Functor { public: Functor() {} void operator()(T x) { /* ... */ } private: /* some attributes here */ }; void Function(T x) { /* ... */ } int main() { Foo<int> foo; foo.bar(2, Functor); // No problem foo.bar(2, Function); // <unresolved overloaded function type> return 0; }

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  • Work with function references

    - by Ockonal
    Hello, I have another one question about functions reference. For example, I have such definition: typedef boost::function<bool (Entity &handle)> behaviorRef; std::map< std::string, ptr_vector<behaviorRef> > eventAssociation; The first question is: how to insert values into such map object? I tried: eventAssociation.insert(std::pair< std::string, ptr_vector<behaviorRef> >(eventType, ptr_vector<behaviorRef>(callback))); But the error: no matching function for call to ‘boost::ptr_vector<boost::function<bool(Entity&)> >::push_back(Entity::behaviorRef&)’ And I undersatnd it, but can't make workable code. The second question is how to call such functions? For example, I have one object of behaviorRef, how to call it with boost::bind with passing my own values?

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  • 2 dimensional arrays passed to a function in c++

    - by John Marcus
    I'm working on doing calculations in a two dimensional array but keep getting a nasty error. i call the function by : if(checkArray(array)) and try to pass it in like this: bool checkArray(double array[][10]) //or double *array[][10] to no avail the error is error: cannot convert ‘double ()[(((unsigned int)(((int)n) + -0x00000000000000001)) + 1)]’ to ‘double’ for argument ‘1’ to ‘bool checkArray(double*)’ code snippet //array declaration int n = 10; double array[n][n]; //function call to pass in array while(f != 25) { cout<<endl; cout<<endl; if(checkArray(array)) //this is the line of the error { cout<<"EXIT EXIT EXIT"<<endl; } f++; } //function declaration bool checkArray(double *array)//, double newArray[][10]) { double length = sizeof(array); for(int i = 0; i < length; i++) for(int j = 0; j < length;j++) { double temp = array[i][j]; } }

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  • How to create PHP method linking?

    - by Kerry
    I've seen other objects that do this: $obj->method1()->method2(); How do I do that? Is each function just modifying the pointer of an object or returning a pointer? I don't know the proper term for this style -- if anyone could help me with that, it would be great.

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  • Fatal error on a non-object

    - by Chris Leah
    Hey, so I have created a function to check the DB for unique entries, but when I call the function it doesn't seem to work and gives me a fatal error any ideas ? Thanks :) //Check for unique entries function checkUnique($table, $field, $compared) { $query = $mysqli->query('SELECT '.$mysqli->real_escape_string($field).' FROM '.$mysqli->real_escape_string($table).' WHERE "'.$mysqli->real_escape_string($field).'" = "'.$mysqli->real_escape_string($compared).'"'); if(!$query){ return TRUE; } else { return FALSE; } } The page calling it..... //Start session session_start(); //Check if the session is already set, if so re-direct to the game if(isset($_SESSION['id'], $_SESSION['logged_in'])){ Header('Location: ../main/index.php'); }; //Require database connection require_once('../global/includes/db.php'); require_once('../global/functions/functions.php'); //Check if the form has been submitted if (isset($_POST['signup'])){ //Validate input if (!empty($_POST['username']) && !empty($_POST['password']) && $_POST['password']==$_POST['password_confirm'] && !empty($_POST['email']) && validateEmail($_POST['email']) == TRUE && checkUnique('users', 'email', $_POST['email']) == TRUE && checkUnique('users', 'username', $_POST['username']) == TRUE) { //Insert user to the database $insert_user = $mysqli->query('INSERT INTO (`username, `password`, `email`, `verification_key`) VALUES ("'.$mysqli->real_escape_string($_POST['username']).'", "'.$mysqli-real_escape_string(md5($_POST['password'])).'", "'.$mysqli->real_escape_string($_POST['email']).'", "'.randomString('alnum', 32). '"') or die($mysqli->error()); //Get user information $getUser = $mysqli->query('SELECT id, username, email, verification_key FROM users WHERE username = "'.$mysqli->real_escape_string($_POST['username']).'"' or die($mysqli->error())); //Check if the $getUser returns true if ($getUser->num_rows == 1) { //Fetch associated fields to this user $row = $getUser->fetch_assoc(); //Set mail() variables $headers = 'From: [email protected]'."\r\n". 'Reply-To: [email protected]'."\r\n". 'X-Mailer: PHP/'.phpversion(); $subject = 'Activate your account (Music Battles.net)'; //Set verification email message $message = 'Dear '.$row['username'].', I would like to welcome you to Music Battles. Although in order to enjoy the gmae you must first activate your account. \n\n Click the following link: http://www.musicbattles.net/home/confirm.php?id='.$row['id'].'key='.$row['verification_key'].'\n Thanks for signing up, enjoy the game! \n Music Battles Team'; //Attempts to send the email if (mail($row['email'], $subject, $message, $headers)) { $msg = '<p class="success">Accound has been created, please go activate it from your email.</p>'; } else { $error = '<p class="error">The account was created but your email was not sent.</p>'; } } else { $error = '<p class="error">Your account was not created.</p>'; } } else { $error = '<p class="error">One or more fields contain non or invalid data.</p>'; } } Erorr.... Fatal error: Call to a member function query() on a non-object in /home/mbattles/public_html/global/functions/functions.php on line 5

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  • Template problems: No matching function for call

    - by Nick Sweet
    I'm trying to create a template class, and when I define a non-member template function, I get the "No matching function for call to randvec()" error. I have a template class defined as: template <class T> class Vector { T x, y, z; public: //constructors Vector(); Vector(const T& x, const T& y, const T& z); Vector(const Vector& u); //accessors T getx() const; T gety() const; T getz() const; //mutators void setx(const T& x); void sety(const T& y); void setz(const T& z); //operations void operator-(); Vector plus(const Vector& v); Vector minus(const Vector& v); Vector cross(const Vector& v); T dot(const Vector& v); void times(const T& s); T length() const; //Vector<T>& randvec(); //operators Vector& operator=(const Vector& rhs); friend std::ostream& operator<< <T>(std::ostream&, const Vector<T>&); }; and the function in question, which I've defined after all those functions above, is: //random Vector template <class T> Vector<double>& randvec() { const int min=-10, max=10; Vector<double>* r = new Vector<double>; int randx, randy, randz, temp; const int bucket_size = RAND_MAX/(max-min +1); temp = rand(); //voodoo hackery do randx = (rand()/bucket_size)+min; while (randx < min || randx > max); r->setx(randx); do randy = (rand()/bucket_size)+min; while (randy < min || randy > max); r->sety(randy); do randz = (rand()/bucket_size)+min; while (randz < min || randz > max); r->setz(randz); return *r; } Yet, every time I call it in my main function using a line like: Vector<double> a(randvec()); I get that error. However, if I remove the template and define it using 'double' instead of 'T', the call to randvec() works perfectly. Why doesn't it recognize randvec()? P.S. Don't mind the bit labeled voodoo hackery - this is just a cheap hack so that I can get around another problem I encountered.

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  • C++ function will not return

    - by Mike
    I have a function that I am calling that runs all the way up to where it should return but doesn't return. If I cout something for debugging at the very end of the function, it gets displayed but the function does not return. fetchData is the function I am referring to. It gets called by outputFile. cout displays "done here" but not "data fetched" I know this code is messy but can anyone help me figure this out? Thanks //Given an inode return all data of i_block data char* fetchData(iNode tempInode){ char* data; data = new char[tempInode.i_size]; this->currentInodeSize = tempInode.i_size; //Loop through blocks to retrieve data vector<unsigned int> i_blocks; i_blocks.reserve(tempInode.i_blocks); this->currentDataPosition = 0; cout << "currentDataPosition set to 0" << std::endl; cout << "i_blocks:" << tempInode.i_blocks << std::endl; int i = 0; for(i = 0; i < 12; i++){ if(tempInode.i_block[i] == 0) break; i_blocks.push_back(tempInode.i_block[i]); } appendIndirectData(tempInode.i_block[12], &i_blocks); appendDoubleIndirectData(tempInode.i_block[13], &i_blocks); appendTripleIndirectData(tempInode.i_block[14], &i_blocks); //Loop through all the block addresses to get the actual data for(i=0; i < i_blocks.size(); i++){ appendData(i_blocks[i], data); } cout << "done here" << std::endl; return data; } void appendData(int block, char* data){ char* tempBuffer; tempBuffer = new char[this->blockSize]; ifstream file (this->filename, std::ios::binary); int entryLocation = block*this->blockSize; file.seekg (entryLocation, ios::beg); file.read(tempBuffer, this->blockSize); //Append this block to data for(int i=0; i < this->blockSize; i++){ data[this->currentDataPosition] = tempBuffer[i]; this->currentDataPosition++; } data[this->currentDataPosition] = '\0'; } void outputFile(iNode file, string filename){ char* data; cout << "File Transfer Started" << std::endl; data = this->fetchData(file); cout << "data fetched" << std::endl; char *outputFile = (char*)filename.c_str(); ofstream myfile; myfile.open (outputFile,ios::out|ios::binary); int i = 0; for(i=0; i < file.i_size; i++){ myfile << data[i]; } myfile.close(); cout << "File Transfer Completed" << std::endl; return; }

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  • Pipelined function calling another pipelined function.

    - by René Nyffenegger
    Here's a package with two pipelined functions: create or replace type tq84_line as table of varchar2(25); / create or replace package tq84_pipelined as function more_rows return tq84_line pipelined; function go return tq84_line pipelined; end tq84_pipelined; / Ant the corresponding package body: create or replace package body tq84_pipelined as function more_rows return tq84_line pipelined is begin pipe row('ist'); pipe row('Eugen,'); return; end more_rows; function go return tq84_line pipelined is begin pipe row('Mein'); pipe row('Name'); /* start */ for next in ( select column_value line from table(more_rows) ) loop pipe row(next.line); end loop; /* end */ pipe row('ich'); pipe row('weiss'); pipe row('von'); pipe row('nichts.'); end go; end tq84_pipelined; / The important thing is that go sort of calls more_rows with the for next in ... between /* start */ and /* end */ I can use the package as follows: select * from table(tq84_pipelined.go); This is all fine and dandy, but I hoped I could replace the lines between /* start */ and /* end */ with a simple call of more_rows. However, this is obviously not possible, as it generetes a PLS-00221: 'MORE_ROWS' is not a procedure or is undefined. So, my question: is there really no way to shortcut the loop?

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  • "Function object is unsubscriptable" in basic integer to string mapping function

    - by IanWhalen
    I'm trying to write a function to return the word string of any number less than 1000. Everytime I run my code at the interactive prompt it appears to work without issue but when I try to import wordify and run it with a test number higher than 20 it fails as "TypeError: 'function' object is unsubscriptable". Based on the error message, it seems the issue is when it tries to index numString (for example trying to extract the number 4 out of the test case of n = 24) and the compiler thinks numString is a function instead of a string. since the first line of the function is me defining numString as a string of the variable n, I'm not really sure why that is. Any help in getting around this error, or even just help in explaining why I'm seeing it, would be awesome. def wordify(n): # Convert n to a string to parse out ones, tens and hundreds later. numString = str(n) # N less than 20 is hard-coded. if n < 21: return numToWordMap(n) # N between 21 and 99 parses ones and tens then concatenates. elif n < 100: onesNum = numString[-1] ones = numToWordMap(int(onesNum)) tensNum = numString[-2] tens = numToWordMap(int(tensNum)*10) return tens+ones else: # TODO pass def numToWordMap(num): mapping = { 0:"", 1:"one", 2:"two", 3:"three", 4:"four", 5:"five", 6:"six", 7:"seven", 8:"eight", 9:"nine", 10:"ten", 11:"eleven", 12:"twelve", 13:"thirteen", 14:"fourteen", 15:"fifteen", 16:"sixteen", 17:"seventeen", 18:"eighteen", 19:"nineteen", 20:"twenty", 30:"thirty", 40:"fourty", 50:"fifty", 60:"sixty", 70:"seventy", 80:"eighty", 90:"ninety", 100:"onehundred", 200:"twohundred", 300:"threehundred", 400:"fourhundred", 500:"fivehundred", 600:"sixhundred", 700:"sevenhundred", 800:"eighthundred", 900:"ninehundred", } return mapping[num] if __name__ == '__main__': pass

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  • Object value not getting updated in the database using hibernate

    - by user1662917
    I am using Spring,hibernate,jsf with jquery in my application. I am inserting a Question object in the database through the hibernate save query . The question object contains id ,question,answertype and reference to a form object using form_id. Now I want to alter the values of Question object stored in the database by altering the value stored in the list of Question objects at the specified index position. If I alter the value in the list the value in the database is not getting altered by update query . Could you please advise. Question.java package com.otv.model; import java.io.Serializable; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.ManyToOne; import javax.persistence.Table; import org.apache.commons.lang.builder.ToStringBuilder; @Entity @Table(name = "questions") public class Question implements Serializable { @Id @GeneratedValue @Column(name = "id", unique = true, nullable = false) private int id; @Column(name = "question", nullable = false) private String text; @Column(name = "answertype", nullable = false) private String answertype; @ManyToOne(fetch = FetchType.EAGER) @JoinColumn(name = "form_id") private Form form; // @JoinColumn(name = "form_id") // private int formId; public Question() { } public Question(String text, String answertype) { this.text = text; this.answertype = answertype; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getQuestion() { return text; } public void setQuestion(String question) { this.text = question; } public String getAnswertype() { return answertype; } public void setAnswertype(String answertype) { this.answertype = answertype; } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + ((answertype == null) ? 0 : answertype.hashCode()); result = prime * result + id; result = prime * result + ((text == null) ? 0 : text.hashCode()); return result; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; Question other = (Question) obj; if (answertype == null) { if (other.answertype != null) return false; } else if (!answertype.equals(other.answertype)) return false; if (id != other.id) return false; if (text == null) { if (other.text != null) return false; } else if (!text.equals(other.text)) return false; return true; } public void setForm(Form form) { this.form = form; } @Override public String toString() { return ToStringBuilder.reflectionToString(this); } } Form.java package com.otv.model; import java.io.Serializable; import java.util.ArrayList; import java.util.List; import javax.persistence.CascadeType; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.OneToMany; import javax.persistence.Table; import org.apache.commons.lang.builder.ToStringBuilder; @Entity @Table(name = "FORM") public class Form implements Serializable { @Id @GeneratedValue @Column(name = "id", unique = true, nullable = false) private int id; @Column(name = "name", nullable = false) private String name; @Column(name = "description", nullable = false) private String description; @OneToMany(mappedBy = "form", fetch = FetchType.EAGER, cascade = CascadeType.ALL) List<Question> questions = new ArrayList<Question>(); public Form(String name) { super(); this.name = name; } public Form() { super(); } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public List<Question> getQuestions() { return questions; } public void setQuestions(List<Question> formQuestions) { this.questions = formQuestions; } public void addQuestion(Question question) { questions.add(question); question.setForm(this); } public void removeQuestion(Question question) { questions.remove(question); question.setForm(this); } @Override public String toString() { return ToStringBuilder.reflectionToString(this); } public void replaceQuestion(int index, Question question) { Question prevQuestion = questions.get(index); // prevQuestion.setQuestion(question.getQuestion()); // prevQuestion.setAnswertype(question.getAnswertype()); question.setId(prevQuestion.getId()); question.setForm(this); questions.set(index, question); } } QuestionDAO.java package com.otv.user.dao; import java.util.List; import org.hibernate.SessionFactory; import com.otv.model.Question; public class QuestionDAO implements IQuestionDAO { private SessionFactory sessionFactory; public SessionFactory getSessionFactory() { return sessionFactory; } public void setSessionFactory(SessionFactory sessionFactory) { this.sessionFactory = sessionFactory; } public void addQuestion(Question question) { getSessionFactory().getCurrentSession().save(question); } public void deleteQuestion(Question question) { getSessionFactory().getCurrentSession().delete(question); } public void updateQuestion(Question question) { getSessionFactory().getCurrentSession().update(question); } public Question getQuestionById(int id) { List list = getSessionFactory().getCurrentSession().createQuery("from Questions where id=?") .setParameter(0, id).list(); return (Question) list.get(0); } }

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  • PHP - Calling function inside another class -> function

    - by Kolind
    I'm trying to do this: class database { function editProvider($post) { $sql = "UPDATE tbl SET "; foreach($post as $key => $val): if($key != "providerId") { $val = formValidate($val); $sqlE[] = "`$key`='$val'"; } endforeach; $sqlE = implode(",", $sqlE); $where = ' WHERE `id` = \''.$post['id'].'\''; $sql = $sql . $sqlE . $where; $query = mysql_query($sql); if($query){ return true; } } // }//end class And then use this function * INSIDE of another class *: function formValidate($string){ $string = trim($string); $string = mysql_real_escape_string($string); return $string; } // .. on $val. Why doesn't this work? if I write in a field of the form, it's not escaping anything at all. How can that be? * UPDATE * handler.php: if(isset($_GET['do'])){ if($_GET['do'] == "addLogin") { $addLogin = $db->addLogin($_POST); } if($_GET['do'] == "addProvider") { $addProvider = $db->addProvider($_POST); } if($_GET['do'] == "editProfile") { $editProfile = $db->editProfile($_POST); } if($_GET['do'] == "editProvider") { $editProvider = $db->editProvider($_POST); } } //end if isset get do ** The editProvider function works fine except for this :-) **

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  • Ongoing confusion about ivars and properties in objective C

    - by Earl Grey
    After almost 8 months being in ios programming, I am again confused about the right approach. Maybe it is not the language but some OOP principle I am confused about. I don't know.. I was trying C# a few years back. There were fields (private variables, private data in an object), there were getters and setters (methods which exposed something to the world) ,and properties which was THE exposed thing. I liked the elegance of the solution, for example there could be a class that would have a property called DailyRevenue...a float...but there was no private variable called dailyRevenue, there was only a field - an array of single transaction revenues...and the getter for DailyRevenue property calculated the revenue transparently. If somehow the internals of daily revenue calculation would change, it would not affect somebody who consumed my DailyRevenue property in any way, since he would be shielded from getter implementation. I understood that sometimes there was , and sometimes there wasn't a 1-1 relationship between fields and properties. depending on the requirements. It seemed ok in my opinion. And that properties are THE way to acces the data in object. I know the difference betweeen private, protected, and public keyword. Now lets get to objectiveC. On what factor should I base my decision about making someting only an ivar or making it as a property? Is the mental model the same as I describe above? I know that ivars are "protected" by default, not "private" asi in c#..But thats ok I think, no big deal for my presnet level of understanding the whole ios development. The point is ivars are not accesible from outside (given i don't make them public..but i won't). The thing that clouds my clear understanding is that I can have IBOutlets from ivars. Why am I seeing internal object data in the UI? *Why is it ok?* On the other hand, if I make an IBOutlet from property, and I do not make it readonly, anybody can change it. Is this ok too? Let's say I have a ParseManager object. This object would use a built in Foundation framework class called NSXMLParser. Obviously my ParseManager will utilize this nsxmlparser's capabilities but will also do some additional work. Now my question is, who should initialize this NSXMLParser object and in which way should I make a reference to it from the ParseManager object, when there is a need to parse something. A) the ParseManager -1) in its default init method (possible here ivar - or - ivar+ppty) -2) with lazyloading in getter (required a ppty here) B) Some other object - who will pass a reference to NSXMLParser object to the ParseManager object. -1) in some custom initializer (initWithParser:(NSXMLPArser *) parser) when creating the ParseManager object.. A1 - the problem is, we create a parser and waste memory while it is not yet needed. However, we can be sure that all methods that are part ot ParserManager object, can use the ivar safely, since it exists. A2 - the problem is, the nsxmlparser is exposed to outside world, although it could be read only. Would we want a parser to be exposed in some scenario? B1 - this could maybe be useful when we would want to use more types of parsers..i dont know... I understand that architectural requirements and and language is not the same. But clearly the two are in relation. How to get out of that mess of my? Please bear with me, I wasn't able to come up with a single ultimate question. And secondly, it's better to not scare me with some superadvanced newspeak that talks about some crazy internals (what the compiler does) and edge cases.

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  • How to pass object from one activity to another in android

    - by kaibuki
    Hi I am trying to work on sending an object of my "Customer" class from one activity and display on other activity. the code for the customer class : `package com.kaibuki; public class Customer { private String firstName, lastName, Address; int Age; public Customer(String fname, String lname, int age, String address) { firstName = fname; lastName = lname; Age = age; Address = address; } public String printValues() { String data = null; data = "First Name :" + firstName + " Last Name :" + lastName + " Age : " + Age + " Address : " + Address; return data; } } I want to send its object from one activity to another and then display the data on the other activity. Please need urgent help. Thanks alot Kai`

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  • Is learning the Caché database hard coming from relational databases and object oriented programming

    - by Edelcom
    I am currently running the local version of Caché on my system in order to determine if I can (and will) take on a new possible project. The current project uses Delphi 7 as a front end calling a Caché dll where the business logic is stored in the database. I have a background of Sqlserver and Firebird (and before Access and Paradox) as databases. I use Delphi 7 for 95% of my Windows development, so I know about object programming. I would like to recieve opinions from persons having used Caché and either SqlServer, Firebird or Oracle and having developed in Delphi (or C++ or C# - an object oriented language). I have read the pro's and con's from other questions, but I am not asking for this, I need input from Caché developers. Thanks in advance.

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  • javascript summary function

    - by Phil Jackson
    Hello, im trying to make a small name summary function depending on the size of the elements container, here's what I have; function shorten_text(str, size){ size = size.match( /[0-9]*/ ); var endValue = Math.floor( Number(size) / 10 ); var number; var newStr; for ( number = 0; number <= endValue; number++ ) { if( str[number].length != 0 ) { newStr += str[number]; } } return newStr + '...'; } shorten_text('Phil Jackson', '94px'); // output should be 'Phil Jack...' What I seem to get is undefinedundef... can anyone see where I am going wrong?

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  • VB.NET 2008 - Anonymous Function

    - by James Brauman
    Hi, On Form Load I populate a menu with all possible colors so they user can pick a color. However when they pick a color the forecolor of my label is not changed. Private Sub MainForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load ' When the form loads, we want to populate the color menu item with all the possible colors that we could change the label to. For Each currentColor As KnownColor In [Enum].GetValues(GetType(KnownColor)) ' Declare the knowColor again - we must do this to be able to do anonymous delegates in VB.NET Dim actualCurrentColor As KnownColor = currentColor ' Get the name for this color Dim colorName As String = [Enum].GetName(GetType(KnownColor), actualCurrentColor) ' Create a new menu item for this color Dim newMenuItem As ToolStripMenuItem = New ToolStripMenuItem(colorName) ' Add a handler to this menu item so when it is clicked, we change the heading color AddHandler newMenuItem.Click, Function(s As System.Object, events As System.EventArgs) (HeadingLabel.ForeColor = Color.FromKnownColor(actualCurrentColor)) ' Add the menu item to the colors menu ColorToolStripMenuItem.DropDownItems.Add(newMenuItem) Next End Sub What am I doing wrong? Thanks

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  • Constructing a hash table/hash function.

    - by nn
    Hi, I would like to construct a hash table that looks up keys in sequences (strings) of bytes ranging from 1 to 15 bytes. I would like to store an integer value, so I imagine an array for hashing would suffice. I'm having difficulty conceptualizing how to construct a hash function such that given the key would give an index into the array. Any assistance would be much appreiated. The maximum number of entries in the hash is: 4081*15 + 4081*14 + ... 4081 = 4081((15*(16))/2) = 489720. So for example: int table[489720]; int lookup(unsigned char *key) { int index = hash(key); return table[index]; } How can I compute hash(key). I'd preferably like to get a perfect hash function. Thanks.

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