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  • Function that requires many parameters

    - by user877329
    I have a problem related to this: Are there guidelines on how many parameters a function should accept? In my case, I have a function that describes a rounded rectangle. The caller specifies An integer which determines how the rectangle should be merged into previously created shapes An Anchor, which is a point that is used for alignment (right, left, top, bottom etc). (0,-1) means that position (next parameter) describes the top, middle point of the rectangle. The position of the rectangle Width and height Corner radius Should I use Parameter Object pattern in this case? It is hard to see how these parameters are related

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  • python factory function best practices

    - by Jason S
    Suppose I have a file foo.py containing a class Foo: class Foo(object): def __init__(self, data): ... Now I want to add a function that creates a Foo object in a certain way from raw source data. Should I put it as a static method in Foo or as another separate function? class Foo(object): def __init__(self, data): ... # option 1: @staticmethod def fromSourceData(sourceData): return Foo(processData(sourceData)) # option 2: def makeFoo(sourceData): return Foo(processData(sourceData)) I don't know whether it's more important to be convenient for users: foo1 = foo.makeFoo(sourceData) or whether it's more important to maintain clear coupling between the method and the class: foo1 = foo.Foo.fromSourceData(sourceData)

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  • Calling a parameterized javascript function from php [migrated]

    - by Ginger
    I need to call a javascript function from php, by passing a value in php variable. My code goes like this: echo '<tr class="trlight"><td onclick="callVehicle('.$qry_vehicleid.');"><label>Call Vehicle</label>&nbsp;</td></tr>'; And in javascript file I try to execute the following code: function callVehicle(vid) { alert('Call '+vid); document.getElementById("SearchResult").style.visibility="hidden"; } and an error test is not defined occurs. test is the value that I assigned to variable $qry_vehicleid. Can someone please point out what the mistake is?

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  • PHP user created function return values problem

    - by faX
    Okay I'm new here and I have been trying to figure this out all day I have two functions one calling the other but my functions only returns the last value for example 29 when it should return multiple values. As wondering how can I fix this problem so that my functions return all the values. Here is my PHP code. function parent_comments(){ if(articles_parent_comments_info($_GET['article_id']) !== false){ foreach(articles_parent_comments_info($_GET['article_id']) as $comment_info){ $comment_id = filternum($comment_info['comment_id']); reply_comment_count($comment_id); } } } function reply_comment_count($parent_id){ if(articles_reply_comments_info($_GET['article_id']) !== false){ foreach(articles_reply_comments_info($_GET['article_id']) as $reply_info){ $comment_id = filternum($reply_info['comment_id']); $reply_id = filternum($reply_info['parent_id']); if($parent_id === $reply_id){ reply_comment_count($comment_id); } } } return $comment_id; }

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  • Double Buffering for Game objects, what's a nice clean generic C++ way?

    - by Gary
    This is in C++. So, I'm starting from scratch writing a game engine for fun and learning from the ground up. One of the ideas I want to implement is to have game object state (a struct) be double-buffered. For instance, I can have subsystems updating the new game object data while a render thread is rendering from the old data by guaranteeing there is a consistent state stored within the game object (the data from last time). After rendering of old and updating of new is finished, I can swap buffers and do it again. Question is, what's a good forward-looking and generic OOP way to expose this to my classes while trying to hide implementation details as much as possible? Would like to know your thoughts and considerations. I was thinking operator overloading could be used, but how do I overload assign for a templated class's member within my buffer class? for instance, I think this is an example of what I want: doublebuffer<Vector3> data; data.x=5; //would write to the member x within the new buffer int a=data.x; //would read from the old buffer's x member data.x+=1; //I guess this shouldn't be allowed If this is possible, I could choose to enable or disable double-buffering structs without changing much code. This is what I was considering: template <class T> class doublebuffer{ T T1; T T2; T * current=T1; T * old=T2; public: doublebuffer(); ~doublebuffer(); void swap(); operator=()?... }; and a game object would be like this: struct MyObjectData{ int x; float afloat; } class MyObject: public Node { doublebuffer<MyObjectData> data; functions... } What I have right now is functions that return pointers to the old and new buffer, and I guess any classes that use them have to be aware of this. Is there a better way?

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  • What is an overloaded operator in c++?

    - by Jeff
    I realize this is a basic question but I have searched online, been to cplusplus.com, read through my book, and I can't seem to grasp the concept of overloaded operators. A specific example from cplusplus.com is: // vectors: overloading operators example #include <iostream> using namespace std; class CVector { public: int x,y; CVector () {}; CVector (int,int); CVector operator + (CVector); }; CVector::CVector (int a, int b) { x = a; y = b; } CVector CVector::operator+ (CVector param) { CVector temp; temp.x = x + param.x; temp.y = y + param.y; return (temp); } int main () { CVector a (3,1); CVector b (1,2); CVector c; c = a + b; cout << c.x << "," << c.y; return 0; } from http://www.cplusplus.com/doc/tutorial/classes2/ but reading through it I'm still not understanding them at all. I just need a basic example of the point of the overloaded operator (which I assume is the "CVector CVector::operator+ (CVector param)"). There's also this example from wikipedia: Time operator+(const Time& lhs, const Time& rhs) { Time temp = lhs; temp.seconds += rhs.seconds; if (temp.seconds >= 60) { temp.seconds -= 60; temp.minutes++; } temp.minutes += rhs.minutes; if (temp.minutes >= 60) { temp.minutes -= 60; temp.hours++; } temp.hours += rhs.hours; return temp; } from "http://en.wikipedia.org/wiki/Operator_overloading" The current assignment I'm working on I need to overload a ++ and a -- operator. Thanks in advance for the information and sorry about the somewhat vague question, unfortunately I'm just not sure on it at all.

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  • dumping the source code for an anonymous function

    - by intuited
    I'm working with a lot of anonymous functions, ie functions declared as part of a dictionary, aka "methods". It's getting pretty painful to debug, because I can't tell what function the errors are happening in. Vim's backtraces look like this: Error detected while processing function NamedFunction..2111..2105: line 1: E730: using List as a String This trace shows that the error occurred in the third level down the stack, on the first line of anonymous function #2105. IE NamedFunction called anonymous function #2111, which called anonymous function #2105. NamedFunction is one declared through the normal function NamedFunction() ... endfunction syntax; the others were declared using code like function dict.func() ... endfunction. So obviously I'd like to find out which function has number 2105. Assuming that it's still in scope, it's possible to find out what Dictionary entry references it by dumping all of the dictionary variables that might contain that reference. This is sort of awkward and it's difficult to be systematic about it, though I guess I could code up a function to search through all of the loaded dictionaries for a reference to that function, watching out for circular references. Although to be really thorough, it would have to search not only script-local and global dictionaries, but buffer-local dictionaries as well; is there a way to access another buffer's local variables? Anyway I'm wondering if it's possible to dump the source code for the anonymous function instead. This would be a lot easier and probably more reliable.

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  • Given a main function and a cleanup function, how (canonically) do I return an exit status in Bash/Linux?

    - by Zac B
    Context: I have a bash script (a wrapper for other scripts, really), that does the following pseudocode: do a main function if the main function returns: $returncode = $? #most recent return code if the main function runs longer than a timeout: kill the main function $returncode = 140 #the semi-canonical "exceeded allowed wall clock time" status run a cleanup function if the cleanup function returns an error: #nonzero return code exit $? #exit the program with the status returned from the cleanup function else #cleanup was successful .... Question: What should happen after the last line? If the cleanup function was successful, but the main function was not, should my program return 0 (for the successful cleanup), or $returncode, which contains the (possibly nonzero and unsuccessful) return code of the main function? For a specific application, the answer would be easy: "it depends on what you need the script for." However, this is more of a general/canonical question (and if this is the wrong place for it, kill it with fire): in Bash (or Linux in general) programming, do you typically want to return the status that "means" something (i.e. $returncode) or do you ignore such subjectivities and simply return the code of the most recent function? This isn't Bash-specific: if I have a standalone executable of any kind, how, canonically should it behave in these cases? Obviously, this is somewhat debatable. Even if there is a system for these things, I'm sure that a lot of people ignore it. All the same, I'd like to know. Cheers!

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  • What does it mean to pass a &variable to a function? E.g., string& insert ( size_t pos1, const strin

    - by Bob Montgomery
    I understand passing a pointer, and returning a pointer: char * strcat ( char * destination, const char * source ); You're passing a variable that contains the address to a char; returning the same. But what does it mean to pass something using the reference operator? Or to return it? string& insert ( size_t pos1, const string& str ); I mean, I understand what actually happens, I just don't understand the notation. Why isn't the notation this instead: string * insert ( size_t pos1, const string * str ); //made up I presume it has something to do with passing/returning the instance of a class, but what? Is this syntax valid; if not why not and if so what does it mean? char & strcat ( char & destination, const char & source ); //made up (all of the function declarations, except the last made-up two, are from http://www.cplusplus.com )

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  • How to define and use a friend function to a temlate class with the same template?

    - by Narek
    I have written the following code: #include <iostream> using namespace std; template <class T> class AA { T a; public: AA() { a = 7; } friend void print(const AA<T> & z); }; template <class T> void print(const AA<T> & z) { cout<<"Print: "<<z.a<<endl; } void main() { AA<int> a; print<int>(a); } And getting the following error: error C2248: 'AA<T>::a' : cannot access private member declared in class 'AA<T>' 1> with 1> [ 1> T=int 1> ] 1> c:\users\narek\documents\visual studio 2008\projects\aaa\aaa\a.cpp(7) : see declaration of 'AA<T>::a' 1> with 1> [ 1> T=int 1> ] 1> c:\users\narek\documents\visual studio 2008\projects\aaa\aaa\a.cpp(30) : see reference to function template instantiation 'void print<int>(const AA<T> &)' being compiled 1> with 1> [ 1> T=int 1> ] What's wrong?

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  • Oracle User definied aggregate function for varray of varchar

    - by baju
    I am trying to write some aggregate function for the varray and I get this error code when I'm trying to use it with data from the DB: ORA-00600 internal error code, arguments: [kodpunp1], [], [], [], [], [], [], [], [], [], [], [] [koxsihread1], [0], [3989], [45778], [], [], [], [], [], [], [], [] Code of the function is really simple(in fact it does nothing ): create or replace TYPE "TEST_VECTOR" as varray(10) of varchar(20) ALTER TYPE "TEST_VECTOR" MODIFY LIMIT 4000 CASCADE create or replace type Test as object( lastVector TEST_VECTOR, STATIC FUNCTION ODCIAggregateInitialize(sctx in out Test) return number, MEMBER FUNCTION ODCIAggregateIterate(self in out Test, value in TEST_VECTOR) return number, MEMBER FUNCTION ODCIAggregateMerge(self IN OUT Test, ctx2 IN Test) return number, MEMBER FUNCTION ODCIAggregateTerminate(self IN Test, returnValue OUT TEST_VECTOR, flags IN number) return number ); create or replace type body Test is STATIC FUNCTION ODCIAggregateInitialize(sctx in out Test) return number is begin sctx := Test(TEST_VECTOR()); return ODCIConst.Success; end; MEMBER FUNCTION ODCIAggregateIterate(self in out Test, value in TEST_VECTOR) return number is begin self.lastVector := value; return ODCIConst.Success; end; MEMBER FUNCTION ODCIAggregateMerge(self IN OUT Test, ctx2 IN Test) return number is begin return ODCIConst.Success; end; MEMBER FUNCTION ODCIAggregateTerminate(self IN Test, returnValue OUT TEST_VECTOR, flags IN number) return number is begin returnValue := self.lastVector; return ODCIConst.Success; end; end; create or replace FUNCTION test_fn (input TEST_VECTOR) RETURN TEST_VECTOR PARALLEL_ENABLE AGGREGATE USING Test; Next I create some test data: create table t1_test_table( t1_id number not null, t1_value TEST_VECTOR not null, Constraint PRIMARY_KEY_1 PRIMARY KEY (t1_id) ) Next step is to put some data to the table insert into t1_test_table (t1_id,t1_value) values (1,TEST_VECTOR('x','y','z')) Now everything is prepared to perform queries: Select test_fn(TEST_VECTOR('y','x')) from dual Query above work well Select test_fn(t1_value) from t1_test_table where t1_id = 1 Version of Oracle DBMS I use: 11.2.0.3.0 Does anyone tried do such a thing? What can be the reason that it does not work? How to solve it? Thanks in advance for help.

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  • Where are the function address literals in c++?

    - by academicRobot
    First of all, maybe literals is not the right term for this concept, but its the closest I could think of (not literals in the sense of functions as first class citizens). <UPDATE> After some reading with help from answer by Chris Dodd, what I'm looking for is literal function addresses as template parameters. Chris' answer indicates how to do this for standard functions, but how can the addresses of member functions be used as template parameters? Since the standard prohibits non-static member function addresses as template parameters (c++03 14.3.2.3), I suspect the work around is quite complicated. Any ideas for a workaround? Below the original form of the question is left as is for context. </UPDATE> The idea is that when you make a conventional function call, it compiles to something like this: callq <immediate address> But if you make a function call using a function pointer, it compiles to something like this: mov <memory location>,%rax callq *%rax Which is all well and good. However, what if I'm writing a template library that requires a callback of some sort with a specified argument list and the user of the library is expected to know what function they want to call at compile time? Then I would like to write my template to accept a function literal as a template parameter. So, similar to template <int int_literal> struct my_template {...};` I'd like to write template <func_literal_t func_literal> struct my_template {...}; and have calls to func_literal within my_template compile to callq <immediate address>. Is there a facility in C++ for this, or a work around to achieve the same effect? If not, why not (e.g. some cataclysmic side effects)? How about C++0x or another language? Solutions that are not portable are fine. Solutions that include the use of member function pointers would be ideal. I'm not particularly interested in being told "You are a <socially unacceptable term for a person of low IQ>, just use function pointers/functors." This is a curiosity based question, and it seems that it might be useful in some (albeit limited) applications. It seems like this should be possible since function names are just placeholders for a (relative) memory address, so why not allow more liberal use (e.g. aliasing) of this placeholder. p.s. I use function pointers and functions objects all the the time and they are great. But this post got me thinking about the don't pay for what you don't use principle in relation to function calls, and it seems like forcing the use of function pointers or similar facility when the function is known at compile time is a violation of this principle, though a small one. Edit The intent of this question is not to implement delegates, rather to identify a pattern that will embed a conventional function call, (in immediate mode) directly into third party code, possibly a template.

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  • Constructor Overload Problem in C++ Inheritance

    - by metdos
    Here my code snippet: class Request { public: Request(void); ……….. } Request::Request(void) { qDebug()<<"Request: "<<"Hello World"; } class LoginRequest :public Request { public: LoginRequest(void); LoginRequest(QDomDocument); …………… } LoginRequest::LoginRequest(void) { qDebug()<<"LoginRequest: "<<"Hello World"; requestType=LOGIN; requestId=-1; } LoginRequest::LoginRequest(QDomDocument doc){ qDebug()<<"LoginRequest: "<<"Hello World with QDomDocument"; LoginRequest::LoginRequest(); xmlDoc_=doc; } When call constructor of Overrided LoginRequest LoginRequest *test=new LoginRequest(doc); I came up with this result: Request: Hello World LoginRequest: Hello World with QDomDocument Request: Hello World LoginRequest: Hello World Obviously both constructor of LoginRequest called REquest constructor. Is there any way to cape with this situation? I can construct another function that does the job I want to do and have both constructors call that function. But I wonder is there any solution?

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  • Custom string class (C++)

    - by Sanctus2099
    Hey guys. I'm trying to write my own C++ String class for educational and need purposes. The first thing is that I don't know that much about operators and that's why I want to learn them. I started writing my class but when I run it it blocks the program but does not do any crash. Take a look at the following code please before reading further: class CString { private: char* cstr; public: CString(); CString(char* str); CString(CString& str); ~CString(); operator char*(); operator const char*(); CString operator+(const CString& q)const; CString operator=(const CString& q); }; First of all I'm not so sure I declared everything right. I tried googleing about it but all the tutorials about overloading explain the basic ideea which is very simple but lack to explain how and when each thing is called. For instance in my = operator the program calls CString(CString& str); but I have no ideea why. I have also attached the cpp file below: CString::CString() { cstr=0; } CString::CString(char *str) { cstr=new char[strlen(str)]; strcpy(cstr,str); } CString::CString(CString& q) { if(this==&q) return; cstr = new char[strlen(q.cstr)+1]; strcpy(cstr,q.cstr); } CString::~CString() { if(cstr) delete[] cstr; } CString::operator char*() { return cstr; } CString::operator const char* () { return cstr; } CString CString::operator +(const CString &q) const { CString s; s.cstr = new char[strlen(cstr)+strlen(q.cstr)+1]; strcpy(s.cstr,cstr); strcat(s.cstr,q.cstr); return s; } CString CString::operator =(const CString &q) { if(this!=&q) { if(cstr) delete[] cstr; cstr = new char[strlen(q.cstr)+1]; strcpy(cstr,q.cstr); } return *this; } For testing I used a code just as simple as this CString a = CString("Hello") + CString(" World"); printf(a); I tried debugging it but at a point I get lost. First it calls the constructor 2 times for "hello" and for " world". Then it get's in the + operator which is fine. Then it calls the constructor for the empty string. After that it get's into "CString(CString& str)" and now I'm lost. Why is this happening? After this I noticed my string containing "Hello World" is in the destructor (a few times in a row). Again I'm very puzzeled. After converting again from char* to Cstring and back and forth it stops. It never get's into the = operator but neither does it go further. printf(a) is never reached. I use VisualStudio 2010 for this but it's basically just standard c++ code and thus I don't think it should make that much of a difference

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  • Constructor Overload Problem in C++ Inherrentance

    - by metdos
    Here my code snippet: class Request { public: Request(void); ……….. } Request::Request(void) { qDebug()<<"Request: "<<"Hello World"; } class LoginRequest :public Request { public: LoginRequest(void); LoginRequest(QDomDocument); …………… } LoginRequest::LoginRequest(void) { qDebug()<<"LoginRequest: "<<"Hello World"; requestType=LOGIN; requestId=-1; } LoginRequest::LoginRequest(QDomDocument doc){ qDebug()<<"LoginRequest: "<<"Hello World with QDomDocument"; LoginRequest::LoginRequest(); xmlDoc_=doc; } When call constructor of Overrided LoginRequest LoginRequest *test=new LoginRequest(doc); I came up with this result: Request: Hello World LoginRequest: Hello World with QDomDocument Request: Hello World LoginRequest: Hello World Obviously both constructor of LoginRequest called REquest constructor. Is there any way to cape with this situation? I can construct another function that does the job I want to do and have both constructors call that function. But I wonder is there any solution?

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  • c++ specialized overload?

    - by acidzombie24
    -edit- i am trying to close the question. i solved the problem with boost::is_base_and_derived In my class i want to do two things. 1) Copy int, floats and other normal values 2) Copy structs that supply a special copy function (template T copyAs(); } the struct MUST NOT return int's unless i explicitly say ints. I do not want the programmer mistaking the mistake by doing int a = thatClass; -edit- someone mention classes dont return anything, i mean using the operator Type() overload. How do i create my copy operator in such a way i can copy both 1) ints, floats etc and the the struct restricted in the way i mention in 2). i tried doing template <class T2> T operator = (const T2& v); which would cover my ints, floats etc. But how would it differentiate from structs? so i wrote T operator = (const SomeGenericBase& v); The idea was the GenericBase would be unsed instead then i can do v.Whatever. But that backfires bc the functions i want wouldnt exist, unless i use virtual, but virtual templates dont exist. Also i would hate to use virtual I think the solution is to get rid of ints and have it convert to something that can do .as(). So i wrote something up but now i have the same problem, how does that differentiate ints and structs that have the .as() function template?

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  • Overload the behavior of count() when called on certain objects

    - by Tom
    In PHP 5, you can use magic methods, overload some classes, etc. In C++, you can implement functions that exist is STL as long as the argument types are different. Is there a way to do this in PHP? An example of what I'd like to do is this: class a { function a() { $this->list = array("1", "2"); } } $blah = new a(); count($blah); I would like blah to return 2. IE count the values of a specific array in the class. So in C++, the way I would do this might look like this: int count(a varName) { return count(varName->list); } Basically, I am trying to simplify data calls for a large application so I can call do this: count($object); rather than count($object->list); The list is going to be potentially a list of objects so depending on how it's used, it could be really nasty statement if someone has to do it the current way: count($object->list[0]->list[0]->list); So, can I make something similar to this: function count(a $object) { count($object->list); } I know PHP's count accepts a mixed var, so I don't know if I can override an individual type.

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  • SQL SERVER – Puzzle to Win Print Book – Write T-SQL Self Join Without Using FIRST _VALUE and LAST_VALUE

    - by pinaldave
    Last week we asked a puzzle SQL SERVER – Puzzle to Win Print Book – Functions FIRST_VALUE and LAST_VALUE with OVER clause and ORDER BY . This puzzle got very interesting participation. The details of the winner is listed here. In this puzzle we received two very important feedback. This puzzle cleared the concepts of First_Value and Last_Value to the participants. As this was based on SQL Server 2012 many could not participate it as they have yet not installed SQL Server 2012. I really appreciate the feedback of user and decided to come up something as fun and helps learn new feature of SQL Server 2012. Please read yesterday’s blog post SQL SERVER – Introduction to LEAD and LAG – Analytic Functions Introduced in SQL Server 2012 before continuing this puzzle as it is based on yesterday’s post. Yesterday I ran following query which uses functions LEAD and LAG. USE AdventureWorks GO SELECT s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty, FIRST_VALUE(SalesOrderDetailID) OVER (ORDER BY SalesOrderDetailID) FstValue, LAST_VALUE(SalesOrderDetailID) OVER (ORDER BY SalesOrderDetailID) LstValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty GO The above query will give us the following result: Puzzle: Now use T-SQL Self Join where same table is joined to itself and get the same result without using LEAD or LAG functions. Hint: Introduction to JOINs – Basic of JOINs Self Join A new analytic functions in SQL Server Denali CTP3 – LEAD() and LAG() Rules Leave a comment with your detailed answer by Nov 21's blog post. Open world-wide (where Amazon ships books) If you blog about puzzle’s solution and if you win, you win additional surprise gift as well. Prizes Print copy of my new book SQL Server Interview Questions Amazon|Flipkart If you already have this book, you can opt for any of my other books SQL Wait Stats [Amazon|Flipkart|Kindle] and SQL Programming [Amazon|Flipkart|Kindle]. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Function, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Removing Leading Zeros From Column in Table

    - by pinaldave
    Some questions surprises me and make me write code which I have never explored before. Today was similar experience as well. I have always received the question regarding how to reserve leading zeroes in SQL Server while displaying them on the SSMS or another application. I have written articles on this subject over here. SQL SERVER – Pad Ride Side of Number with 0 – Fixed Width Number Display SQL SERVER – UDF – Pad Ride Side of Number with 0 – Fixed Width Number Display SQL SERVER – Preserve Leading Zero While Coping to Excel from SSMS Today I received a very different question where the user wanted to remove leading zero and white space. I am using the same sample sent by user in this example. USE tempdb GO -- Create sample table CREATE TABLE Table1 (Col1 VARCHAR(100)) INSERT INTO Table1 (Col1) SELECT '0001' UNION ALL SELECT '000100' UNION ALL SELECT '100100' UNION ALL SELECT '000 0001' UNION ALL SELECT '00.001' UNION ALL SELECT '01.001' GO -- Original data SELECT * FROM Table1 GO -- Remove leading zeros SELECT SUBSTRING(Col1, PATINDEX('%[^0 ]%', Col1 + ' '), LEN(Col1)) FROM Table1 GO -- Clean up DROP TABLE Table1 GO Here is the resultset of above script. It will remove any leading zero or space and will display the number accordingly. This problem is a very generic problem and I am confident there are alternate solutions to this problem as well. If you have an alternate solution or can suggest a sample data which does not satisfy the SUBSTRING solution proposed, I will be glad to include them in follow up blog post with due credit. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Function, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Removing Leading Zeros From Column in Table – Part 2

    - by pinaldave
    Earlier I wrote a blog post about Remvoing Leading Zeros from Column In Table. It was a great co-incident that my friend Madhivanan (no need of introduction for him) also post a similar article over on BeyondRelational.com. I strongly suggest to read his blog as well as he has suggested some cool solutions to the same problem. On original blog post asked two questions 1) if my sample for testing is correct and 2) If there is any better method to achieve the same. The response was amazing. I am proud on our SQL Community that we all keep on improving on each other’s contribution. There are some really good suggestions as a comment. Let us go over them right now. Improving the ResultSet I had missed including all zeros in my sample set which was an overlook. Here is the new sample which includes all zero values as well. USE tempdb GO -- Create sample table CREATE TABLE Table1 (Col1 VARCHAR(100)) INSERT INTO Table1 (Col1) SELECT '0001' UNION ALL SELECT '000100' UNION ALL SELECT '100100' UNION ALL SELECT '000 0001' UNION ALL SELECT '00.001' UNION ALL SELECT '01.001' UNION ALL SELECT '0000' GO Now let us go over some of the fantastic solutions which we have received. Response from Rainmaker SELECT CASE PATINDEX('%[^0 ]%', Col1 + ' ‘') WHEN 0 THEN '' ELSE SUBSTRING(Col1, PATINDEX('%[^0 ]%', Col1 + ' '), LEN(Col1)) END FROM Table1 Response from Harsh Solution 1 SELECT SUBSTRING(Col1, PATINDEX('%[^0 ]%', Col1 + 'a'), LEN(Col1)) FROM Table1 Response from Harsh Solution 2 SELECT RIGHT(Col1, LEN(Col1)+1 -PATINDEX('%[^0 ]%', Col1 + 'a' )) FROM Table1 Response from lucazav SELECT T.Col1 , label = CAST( CAST(REPLACE(T.Col1, ' ', '') AS FLOAT) AS VARCHAR(10)) FROM Table1 AS T Response from iamAkashSingh SELECT REPLACE(LTRIM(REPLACE(col1,'0',' ')),' ','0') FROM table1 Here is the resultset of above scripts. It will remove any leading zero or space and will display the number accordingly. If you believe there is a better solution, please leave a comment. I am just glad to see so many various responses and all of them teach us something new. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Function, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • I'd like to know why a function executes fine when called from x but not when called from y

    - by Roland
    When called from archive(), readcont(char *filename) executes fine! Called from runoptions() though, it fails to list the files "archived"! why is this? The program must run in terminal. Use -h as a parameter to view the usage. This program is written to "archive" text files into ".rldzip" files. readcont( char *x) should show the files archived in file (*x) a) Successful call Use the program to archive 3 text files: rldzip.exe a.txt b.txt c.txt FILEXY -a archive() will call readcont and it will work showing the files archived after the binary FILEXY will be created. b) Unsuccessful call After the file is created, use: rldzip.exe FILEXY.rldzip -v You can see that the function crashes! I'd like to know why is this happening! /* Sa se scrie un program care: a) arhiveaza fisiere b) dezarhiveaza fisierele athivate */ #include<stdio.h> #include<stdlib.h> #include<conio.h> #include<string.h> struct content{ char *text; char *flname; }*arc; FILE *f; void readcont(char *x){ FILE *p; if((p = fopen(x, "rb")) == NULL){ perror("Critical error: "); exit(EXIT_FAILURE); } content aux; int i; fread(&i, sizeof(int), 1, p); printf("\nFiles in %s \n\n", x); while(i-- >1 && fread(&aux, sizeof(struct content), 1, p) != 0) printf("%s \n", aux.flname); fclose(p); printf("\n\n"); } void archive(int argc, char **argv){ int i; char inttext[5000], textline[1000]; //Allocate dynamic memory for the content to be archived! arc = (content*)malloc(argc * sizeof(content)); for(i=1; i< argc; i++) { if((f = fopen(argv[i], "r")) == NULL){ printf("%s: ", argv[i]); perror(""); exit(EXIT_FAILURE); } while(!feof(f)){ fgets(textline, 5000, f); strcat(inttext, textline); } arc[i-1].text = (char*)malloc(strlen(inttext) + 1); strcpy(arc[i-1].text, inttext); arc[i-1].flname = (char*)malloc(strlen(argv[i]) + 1); strcpy(arc[i-1].flname, argv[i]); fclose(f); } char *filen; filen=(char*)malloc(strlen(argv[argc])+1+7); strcpy(filen, argv[argc]); strcat(filen, ".rldzip"); f = fopen(filen, "wb"); fwrite(&argc, sizeof(int), 1, f); fwrite(arc, sizeof(content), argc, f); fclose(f); printf("Success! "); for(i=1; i< argc; i++) { (i==argc-1)? printf("and %s ", argv[i]) : printf("%s ", argv[i]); } printf("compressed into %s", filen); readcont(filen); free(filen); } void help(char *v){ printf("\n\n----------------------RLDZIP----------------------\n\nUsage: \n\n Archive n files: \n\n%s $file[1] $file[2] ... $file[n] $output -a\n\nExample:\n%s a.txt b.txt c.txt output -a\n\n\n\nView files:\n\n %s $file.rldzip -v\n\nExample:\n %s fileE.rldzip -v\n\n", v, v, v, v); } void runoptions(int c, char **v){ int i; if(c < 2){ printf("Arguments missing! Use -h for help"); } else{ for(i=0; i<c; i++) if(strcmp(v[i], "-h") == 0){ help(v[0]); exit(2); } for(i=0; i<c; i++) if(strcmp(v[i], "-v") == 0){ if(c != 3){ printf("Arguments misused! Use -h for help"); exit(2); } else { printf("-%s-", v[1]); readcont(v[1]); } } } if(strcmp(v[c-1], "-a") == 0) archive(c-2, v); } main(int argc, char **argv) { runoptions(argc, argv); }

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  • return the result of a query and the total number of rows in a single function

    - by csotelo
    This is a question as might be focused on working in the best way, if there are other alternatives or is the only way: Using Codeigniter ... I have the typical 2 functions of list records and show total number of records (using the page as an alternative). The problem is that they are rather large. Sample 2 functions in my model: count Rows: function get_all_count() { $this->db->select('u.id_user'); $this->db->from('user u'); if($this->session->userdata('detail') != '1') { $this->db->join('management m', 'm.id_user = u.id_user', 'inner'); $this->db->where('id_detail', $this->session->userdata('detail')); if($this->session->userdata('management') === '1') { $this->db->or_where('detail', 1); } else { $this->db->where("id_profile IN ( SELECT e2.id_profile FROM profile e, profile e2, profile_path p, profile_path p2 WHERE e.id_profile = " . $this->session->userdata('profile') . " AND p2.id_profile = e.id_profile AND p.path LIKE(CONCAT(p2.path,'%')) AND e2.id_profile = p.id_profile )", NULL, FALSE); $this->db->where('MD5(u.id_user) <>', $this->session->userdata('id_user')); } } $this->db->where('u.id_user <>', 1); $this->db->where('flag <>', 3); $query = $this->db->get(); return $query->num_rows(); } results per page function get_all($limit, $offset, $sort = '') { $this->db->select('u.id_user, user, email, flag'); $this->db->from('user u'); if($this->session->userdata('detail') != '1') { $this->db->join('management m', 'm.id_user = u.id_user', 'inner'); $this->db->where('id_detail', $this->session->userdata('detail')); if($this->session->userdata('management') === '1') { $this->db->or_where('detail', 1); } else { $this->db->where("id_profile IN ( SELECT e2.id_profile FROM profile e, profile e2, profile_path p, profile_path p2 WHERE e.id_profile = " . $this->session->userdata('profile') . " AND p2.id_profile = e.id_profile AND p.path LIKE(CONCAT(p2.path,'%')) AND e2.id_profile = p.id_profile )", NULL, FALSE); $this->db->where('MD5(u.id_user) <>', $this->session->userdata('id_user')); } } $this->db->where('u.id_user <>', 1); $this->db->where('flag <>', 3); if($sort) $this->db->order_by($sort); $this->db->limit($limit, $offset); $query = $this->db->get(); return $query->result(); } You see, I repeat the most of the functions, the difference is that only the number of fields and management pages. I wonder if there is any alternative to get as much results as the query in a single function. I have seen many tutorials, and all create 2 functions: one to count and another to show results ... Will there be more optimal?

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  • SQL SERVER – Implementing IF … THEN in SQL SERVER with CASE Statements

    - by Pinal Dave
    Here is the question I received the other day in email. “I have business logic in my .net code and we use lots of IF … ELSE logic in our code. I want to move the logic to Stored Procedure. How do I convert the logic of the IF…ELSE to T-SQL. Please help.” I have previously received this answer few times. As data grows the performance problems grows more as well. Here is the how you can convert the logic of IF…ELSE in to CASE statement of SQL Server. Here are few of the examples: Example 1: If you are logic is as following: IF -1 < 1 THEN ‘TRUE’ ELSE ‘FALSE’ You can just use CASE statement as follows: -- SQL Server 2008 and earlier version solution SELECT CASE WHEN -1 < 1 THEN 'TRUE' ELSE 'FALSE' END AS Result GO -- SQL Server 2012 solution SELECT IIF ( -1 < 1, 'TRUE', 'FALSE' ) AS Result; GO If you are interested further about how IIF of SQL Server 2012 works read the blog post which I have written earlier this year . Well, in our example the condition which we have used is pretty simple but in the real world the logic can very complex. Let us see two different methods of how we an do CASE statement when we have logic based on the column of the table. Example 2: If you are logic is as following: IF BusinessEntityID < 10 THEN FirstName ELSE IF BusinessEntityID > 10 THEN PersonType FROM Person.Person p You can convert the same in the T-SQL as follows: SELECT CASE WHEN BusinessEntityID < 10 THEN FirstName WHEN BusinessEntityID > 10 THEN PersonType END AS Col, BusinessEntityID, Title, PersonType FROM Person.Person p However, if your logic is based on multiple column and conditions are complicated, you can follow the example 3. Example 3: If you are logic is as following: IF BusinessEntityID < 10 THEN FirstName ELSE IF BusinessEntityID > 10 AND Title IS NOT NULL THEN PersonType ELSE IF Title = 'Mr.' THEN 'Mister' ELSE 'No Idea' FROM Person.Person p You can convert the same in the T-SQL as follows: SELECT CASE WHEN BusinessEntityID < 10 THEN FirstName WHEN BusinessEntityID > 10 AND Title IS NOT NULL THEN PersonType WHEN Title = 'Mr.' THEN 'Mister' ELSE 'No Idea' END AS Col, BusinessEntityID, Title, PersonType FROM Person.Person p I hope this solution is good enough to convert the IF…ELSE logic to CASE Statement in SQL Server. Let me know if you need further information about the same. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Function, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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