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  • How Can I Generate Random Unqiue Numbers in C#

    - by peace
    public int GenPurchaseOrderNum() { Random random = new Random(); _uniqueNum = random.Next(13287, 21439); return UniqueNum; } I removed unique constraint from the PONumber column in the db because an employee should only generate P.O. # when the deal is set. Otherwise, P.O. # would have 0. P.O. Number used to have unique constraint, this forces employee to generate P.O. in all cases so the db doesn't throw unique constraint error. Since i removed the unique constraint, any quote doesn't have P.O. will carry 0 value. Otherwise, a unique value is generated for P.O. #. However, i don't have a unique constraint in db which makes it hard for me to know whether the application generated P.O. # is unique or not. What should i do? I hope my question is clear enough

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  • IP address numbers in MySQL subquery

    - by Iain Collins
    I have a problem with a subquery involving IPV4 addresses stored in MySQL (MySQL 5.0). The IP addresses are stored in two tables, both in network number format - e.g. the format output by MySQL's INET_ATON(). The first table ('events') contains lots of rows with IP addresses associated with them, the second table ('network_providers') contains a list of provider information for given netblocks. events table (~4,000,000 rows): event_id (int) event_name (varchar) ip_address (unsigned 4 byte int) network_providers table (~60,000 rows): ip_start (unsigned 4 byte int) ip_end (unsigned 4 byte int) provider_name (varchar) Simplified for the purposes of the problem I'm having, the goal is to create an export along the lines of: event_id,event_name,ip_address,provider_name If do a query along the lines of either of the following, I get the result I expect: SELECT provider_name FROM network_providers WHERE INET_ATON('192.168.0.1') >= network_providers.ip_start ORDER BY network_providers.ip_start DESC LIMIT 1 SELECT provider_name FROM network_providers WHERE 3232235521 >= network_providers.ip_start ORDER BY network_providers.ip_start DESC LIMIT 1 That is to say, it returns the correct provider_name for whatever IP I look up (of course I'm not really using 192.168.0.1 in my queries). However, when performing this same query as a subquery, in the following manner, it doesn't yield the result I would expect: SELECT event.id, event.event_name, (SELECT provider_name FROM network_providers WHERE event.ip_address >= network_providers.ip_start ORDER BY network_providers.ip_start DESC LIMIT 1) as provider FROM events Instead the a different (incorrect) value for network_provider is returned - over 90% (but curiously not all) values returned in the provider column contain the wrong provider information for that IP. Using event.ip_address in a subquery just to echo out the value confirms it contains the value I'd expect and that the subquery can parse it. Replacing event.ip_address with an actual network number also works, just using it dynamically in the subquery in this manner that doesn't work for me. I suspect the problem is there is something fundamental and important about subqueries in MySQL that I don't get. I've worked with IP addresses like this in MySQL quite a bit before, but haven't previously done lookups for them using a subquery. The question: I'd really appreciate an example of how I could get the output I want, and if someone here knows, some enlightenment as to why what I'm doing doesn't work so I can avoid making this mistake again. Notes: The actual real-world usage I'm trying to do is considerably more complicated (involving joining two or three tables). This is a simplified version, to avoid overly complicating the question. Additionally, I know I'm not using a between on ip_start & ip_end - that's intentional (the DB's can be out of date, and such cases the owner in the DB is almost always in the next specified range and 'best guess' is fine in this context) however I'm grateful for any suggestions for improvement that relate to the question. Efficiency is always nice, but in this case absolutely not essential - any help appreciated.

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  • How can I search for numbers in a varchar column

    - by dave
    I've got a simple nvarchar(25) column in an SQL database table. Most of the time, this field should contain alphanumeric text. However, due to operator error, there are many instances where it contains only a number. Can I do a simple search in SQL to identify these cases? That is, determine which rows in the table contain only digits in this column. As an extension, could I also search for those column values which contain only digits and a space and/or slash. In other languages (eg. Perl, Java) a regular expression would resolve this quickly and easily. But I haven't been able to find the equivalent in SQL.

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  • Combining Variable Numbers of Lists w/ LINQ

    - by Anthony Compton
    I have a list (List) of objects. Each of those objects contains a list (List) of strings describing them. I'm needing to create a dropdown containing all of the distinct strings used to describe the objects (Cards). To do this, I need a list of distinct strings used. Any idea how/if this can be done with LINQ?

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  • Designing small comparable objects

    - by Thomas Ahle
    Intro Consider you have a list of key/value pairs: (0,a) (1,b) (2,c) You have a function, that inserts a new value between two current pairs, and you need to give it a key that keeps the order: (0,a) (0.5,z) (1,b) (2,c) Here the new key was chosen as the average between the average of keys of the bounding pairs. The problem is, that you list may have milions of inserts. If these inserts are all put close to each other, you may end up with keys such to 2^(-1000000), which are not easily storagable in any standard nor special number class. The problem How can you design a system for generating keys that: Gives the correct result (larger/smaller than) when compared to all the rest of the keys. Takes up only O(logn) memory (where n is the number of items in the list). My tries First I tried different number classes. Like fractions and even polynomium, but I could always find examples where the key size would grow linear with the number of inserts. Then I thought about saving pointers to a number of other keys, and saving the lower/greater than relationship, but that would always require at least O(sqrt) memory and time for comparison. Extra info: Ideally the algorithm shouldn't break when pairs are deleted from the list.

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  • Linenumber for Exception thrown in runtime-compiled DotNET code

    - by David Rutten
    Not quite the same as this thread, but pretty close. My program allows people to enter some VB or C# code which gets compiled, loaded and executed at runtime. My CompilerParams are: CompilerParameters params = new CompilerParameters(); params.GenerateExecutable = false; params.GenerateInMemory = true; params.IncludeDebugInformation = false; params.TreatWarningsAsErrors = false; params.WarningLevel = 4; When this code throws an exception I'd like to be able to display a message box that helps users debug their code. The exception message is easy, but the line-number is where I got stuck. I suspect that in order to get at the line number, I may need to drastically change the CompilerParameters and perhaps even the way these dlls get stored/loaded. Does anyone know the least steps needed to get this to work?

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  • Trying to reduce the speed overhead of an almost-but-not-quite-int number class

    - by Fumiyo Eda
    I have implemented a C++ class which behaves very similarly to the standard int type. The difference is that it has an additional concept of "epsilon" which represents some tiny value that is much less than 1, but greater than 0. One way to think of it is as a very wide fixed point number with 32 MSBs (the integer parts), 32 LSBs (the epsilon parts) and a huge sea of zeros in between. The following class works, but introduces a ~2x speed penalty in the overall program. (The program includes code that has nothing to do with this class, so the actual speed penalty of this class is probably much greater than 2x.) I can't paste the code that is using this class, but I can say the following: +, -, +=, <, > and >= are the only heavily used operators. Use of setEpsilon() and getInt() is extremely rare. * is also rare, and does not even need to consider the epsilon values at all. Here is the class: #include <limits> struct int32Uepsilon { typedef int32Uepsilon Self; int32Uepsilon () { _value = 0; _eps = 0; } int32Uepsilon (const int &i) { _value = i; _eps = 0; } void setEpsilon() { _eps = 1; } Self operator+(const Self &rhs) const { Self result = *this; result._value += rhs._value; result._eps += rhs._eps; return result; } Self operator-(const Self &rhs) const { Self result = *this; result._value -= rhs._value; result._eps -= rhs._eps; return result; } Self operator-( ) const { Self result = *this; result._value = -result._value; result._eps = -result._eps; return result; } Self operator*(const Self &rhs) const { return this->getInt() * rhs.getInt(); } // XXX: discards epsilon bool operator<(const Self &rhs) const { return (_value < rhs._value) || (_value == rhs._value && _eps < rhs._eps); } bool operator>(const Self &rhs) const { return (_value > rhs._value) || (_value == rhs._value && _eps > rhs._eps); } bool operator>=(const Self &rhs) const { return (_value >= rhs._value) || (_value == rhs._value && _eps >= rhs._eps); } Self &operator+=(const Self &rhs) { this->_value += rhs._value; this->_eps += rhs._eps; return *this; } Self &operator-=(const Self &rhs) { this->_value -= rhs._value; this->_eps -= rhs._eps; return *this; } int getInt() const { return(_value); } private: int _value; int _eps; }; namespace std { template<> struct numeric_limits<int32Uepsilon> { static const bool is_signed = true; static int max() { return 2147483647; } } }; The code above works, but it is quite slow. Does anyone have any ideas on how to improve performance? There are a few hints/details I can give that might be helpful: 32 bits are definitely insufficient to hold both _value and _eps. In practice, up to 24 ~ 28 bits of _value are used and up to 20 bits of _eps are used. I could not measure a significant performance difference between using int32_t and int64_t, so memory overhead itself is probably not the problem here. Saturating addition/subtraction on _eps would be cool, but isn't really necessary. Note that the signs of _value and _eps are not necessarily the same! This broke my first attempt at speeding this class up. Inline assembly is no problem, so long as it works with GCC on a Core i7 system running Linux!

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  • excel turning my numbers to floats

    - by femi
    Hello, i have a bit of asp.net code that exports data in a datagrid into excel but i noticed that it messes up a particular field when exporting. eg .. i have the value of something like 89234010000725515875 in a column in the datagrid but when exported, it turns it into 89234+19. Is there any excel formatting that will bring back my original number? thanks

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  • Find a repeated numbers out of 3 boxes

    - by james1
    I have 3 boxes, each box contain 10 piece of numbered paper (1 - 10) but there is a number the same in all 3 boxes eg: box1 has number 4 and box2 has number 4 and box3 also has number 4. How to find that repeated number in java with an efficient/fastest way possible?

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  • More efficient comparison of numbers

    - by Pez Cuckow
    I have an array which is part of a small JS game I am working on I need to check (as often as reasonable) that each of the elements in the array haven't left the "stage" or "playground", so I can remove them and save the script load I have coded the below and was wondering if anyone knew a faster/more efficient way to calculate this. This is run every 50ms (it deals with the movement). Where bots[i][1] is movement in X and bots[i][2] is movement in Y (mutually exclusive). for (var i in bots) { var left = parseInt($("#" + i).css("left")); var top = parseInt($("#" + i).css("top")); var nextleft = left + bots[i][1]; var nexttop = top + bots[i][2]; if(bots[i][1]>0&&nextleft>=PLAYGROUND_WIDTH) { remove_bot(i); } else if(bots[i][1]<0&&nextleft<=-GRID_SIZE) { remove_bot(i); } else if(bots[i][2]>0&&nexttop>=PLAYGROUND_HEIGHT) { remove_bot(i); } else if(bots[i][2]<0&&nexttop<=-GRID_SIZE) { remove_bot(i); } else { //alert(nextleft + ":" + nexttop); $("#" + i).css("left", ""+(nextleft)+"px"); $("#" + i).css("top", ""+(nexttop)+"px"); } } On a similar note the remove_bot(i); function is as below, is this correct (I can't splice as it changes all the ID's of the elements in the array. function remove_bot(i) { $("#" + i).remove(); bots[i] = false; } Many thanks for any advice given!

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  • How to generate a random but unique number and display that number within the source of my image tag

    - by Matthew
    Hello guys, I have done some searching but really haven't found what I'm looking for. What I would like to do is generate a random BUT unique 5 digit number and push whatever number into an img tag on my page. For example when people come to my page this number would generate and get pushed into this image tag: <img src="http://www.sample.com?randomNUM=12345" height="1" width="1" /> I have a mySQL DB and am looking to do this in PHP. Thank, Matt

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  • Storing float numbers as strings in android database

    - by sandis
    So I have an app where I put arbitrary strings in a database and later extract them like this: Cursor DBresult = myDatabase.query(false, Constant.DATABASE_NOTES_TABLE_NAME, new String[] {"myStuff"}, where, null, null, null, null, null); DBresult.getString(0); This works fine in all cases except for when the string looks like a float number, for example "221.123123123". After saving it to the database I can extract the database to my computer and look inside it with a DB-viewer, and the saved number is correct. However, when using cursor.getString() the string "221.123" is returned. I cant for the life of me understand how I can prevent this. I guess I could do a cursor.getDouble() on every single string to see if this gives a better result, but that feels sooo ugly and inefficient. Any suggestions? Cheers, edit: I just made a small test program. This program prints "result: 123.123", when I would like it to print "result: 123.123123123" SQLiteDatabase database = openOrCreateDatabase("databas", Context.MODE_PRIVATE, null); database.execSQL("create table if not exists tabell (nyckel string primary key);"); ContentValues value = new ContentValues(); value.put("nyckel", "123.123123123"); database.insert("tabell", null, value); Cursor result = database.query("tabell", new String[]{"nyckel"}, null, null, null, null, null); result.moveToFirst(); Log.d("TAG","result: " + result.getString(0));

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  • multi-shop orders table and sequential order numbers based on shop

    - by imanc
    Hey, I am looking at building a shop solution that needs to be scalable. Currently it retrieves 1-2000 orders on average per day across multiple country based shops (e.g. uk, us, de, dk, es etc.) but this order could be 10x this amount in two years. I am looking at either using separate country-shop databases to store the orders tables, or looking to combine all into one order table. If all orders exist in one table with a global ID (auto num) and country ID (e.g uk,de,dk etc.), each countries orders would also need to have sequential ordering. So in essence, we'd have to have a global ID and a country order ID, with the country order ID being sequential for countries only, e.g. global ID = 1000, country = UK, country order ID = 1000 global ID = 1001, country = DE, country order ID = 1000 global ID = 1002, country = DE, country order ID = 1001 global ID = 1003, country = DE, country order ID = 1002 global ID = 1004, country = UK, country order ID = 1001 THe global ID would be DB generated and not something I would need to worry about. But I am thinking that I'd have to do a query to get the current country order based ID+1 to find the next sequential number. Two things concern me about this: 1) query times when the table has potentially millions of rows of data and I'm doing a read before a write, 2) the potential for ID number clashes due to simultaneous writes/reads. With a MyISAM table the entire table could be locked whilst the last country order + 1 is retrieved, to prevent ID number clashes. I am wondering if anyone knows of a more elegant solution? Cheers, imanc

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  • Java Regex for matching hexadecimal numbers in a file

    - by Ranman
    So I'm reading in a file (like java program < trace.dat) which looks something like this: 58 68 58 68 40 c 40 48 FA If I'm lucky but more often it has several whitespace characters before and after each line. These are hexadecimal addresses that I'm parsing and I basically need to make sure that I can get the line using a scanner, buffered reader... whatever and make sure I can then convert the hexadecimal to an integer. This is what I have so far: Scanner scanner = new Scanner(System.in); int address; String binary; Pattern pattern = Pattern.compile("^\\s*[0-9A-Fa-f]*\\s*$", Pattern.CASE_INSENSITIVE); while(scanner.hasNextLine()) { address = Integer.parseInt(scanner.next(pattern), 16); binary = Integer.toBinaryString(address); //Do lots of other stuff here } //DO MORE STUFF HERE... So I've traced all my errors to parsing input and stuff so I guess I'm just trying to figure out what regex or approach I need to get this working the way I want.

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  • Rounding values up or down in C#

    - by c11ada
    Hey all, I've created a game which gives a score at the end of the game, but the problem is that this score is sometimes a number with a lot of digits after the decimal point (like 87.124563563566). How would I go about rounding up or down the value so that I could have something like 87.12? Thanks!

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  • Algorithm for assigning a unique series of bits for each user?

    - by Mark
    The problem seems simple at first: just assign an id and represent that in binary. The issue arises because the user is capable of changing as many 0 bits to a 1 bit. To clarify, the hash could go from 0011 to 0111 or 1111 but never 1010. Each bit has an equal chance of being changed and is independent of other changes. What would you have to store in order to go from hash - user assuming a low percentage of bit tampering by the user? I also assume failure in some cases so the correct solution should have an acceptable error rate. I would an estimate the maximum number of bits tampered with would be about 30% of the total set. I guess the acceptable error rate would depend on the number of hashes needed and the number of bits being set per hash. I'm worried with enough manipulation the id can not be reconstructed from the hash. The question I am asking I guess is what safe guards or unique positioning systems can I use to ensure this happens.

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  • Printing out series of numbers in java

    - by Jay
    hi guys i am just doing some reading for myself to learn java and came across this problem and is currently stuck. i need to print out series of number based on the input given by the user. for example, if input = 5, the output should be as follows @1@22@333@4444@55555 import java.util.*; public class ex5{ public static void main(String[] args){ Scanner kb = new Scanner(System.in); System.out.println("Please type a #: "); int input = kb.nextInt(); for(int i=0;i<input;i++){ if(input==1){ System.out.print("@1"); } if(input==2){ System.out.print("@1@22"); } } } } this doesnt seem to be working because this is the output i get Please type a #: 2 @1@22@1@22 im not sure what to put inside the for loop right now and i dont think i am using the for loop here very well either... any help guys?

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  • Visual Studio Question: How to go to a specific file path and line number programmatically?

    - by Jack
    In the Visual Studio output window, you can double click a line that contains a file path and line number and it automatically takes you to that location. In my program, I need to mimic this behavior and be able to click something (a button for example) and do go to a specific file and line number that I tell it to go to. Any help/suggestions would be appreciated. I am working in C#.

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  • sum of logarithams of prime numbers

    - by nadi
    Write a program that computes the sum of the logarithms of all the primes from 2 to some number n, and print out the sum of the logs of the primes, the number n, and the ratio of these two quantities. Test this for different values of n.

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  • How to create list of numbers and append its reverse to it efficiently in Ruby

    - by Kiwi
    Given a minimum integer and maximum integer, I want to create an array which counts from the minimum to the maximum by two, then back down (again by two, repeating the maximum number). For example, if the minimum number is 1 and the maximum is 9, I want [1, 3, 5, 7, 9, 9, 7, 5, 3, 1]. I'm trying to be as concise as possible, which is why I'm using one-liners. In Python, I would do this: range(1, 10, 2) + range(9, 0, -2) In Ruby, which I'm just beginning to learn, all I've come up with so far is: (1..9).inject([]) { |r, num| num%2 == 1 ? r << num : r }.reverse.inject([]) { |r, num| r.unshift(num).push(num) } Which works, but I know there must be a better way. What is it?

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