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  • SQL ENQUIRY In how to Get defined number of records

    - by ramadan2050
    I have a select statement, retrieve about 1000 record I want to modify it to return only some records defined by @startIndex and @count e.g. : If I said @startIndex=20 and @count=20 the result will be : from the 21th record to 40th I try to make it, but it take the same time as if I retrieve the 1000 record what is the best way to do that

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  • mysql_fetch_row() not a valid result resource

    - by user1717305
    I am confused, I don't know what's wrong. I'm about to transfer all data from my first table to the other. Here is my code: $getdata = mysql_query("SELECT Quantity, Description, Total FROM ordercart"); while($row = mysql_fetch_row($getdata)) { foreach($row as $cell){ $query1 = mysql_query("INSERT INTO ordermem (Quantity, Description, Total) VALUES ($cell)",$connect); } mysql_free_result($getdata); } I get the error: Warning: mysql_fetch_row(): 5 is not a valid MySQL result resource.

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  • Slowing process creation under Java?

    - by oconnor0
    I have a single, large heap (up to 240GB, though in the 20-40GB range for most of this phase of execution) JVM [1] running under Linux [2] on a server with 24 cores. We have tens of thousands of objects that have to be processed by an external executable & then load the data created by those executables back into the JVM. Each executable produces about half a megabyte of data (on disk) that when read right in, after the process finishes, is, of course, larger. Our first implementation was to have each executable handle only a single object. This involved the spawning of twice as many executables as we had objects (since we called a shell script that called the executable). Our CPU utilization would start off high, but not necessarily 100%, and slowly worsen. As we began measuring to see what was happening we noticed that the process creation time [3] continually slows. While starting at sub-second times it would eventually grow to take a minute or more. The actual processing done by the executable usually takes less than 10 seconds. Next we changed the executable to take a list of objects to process in an attempt to reduce the number of processes created. With batch sizes of a few hundred (~1% of our current sample size), the process creation times start out around 2 seconds & grow to around 5-6 seconds. Basically, why is it taking so long to create these processes as execution continues? [1] Oracle JDK 1.6.0_22 [2] Red Hat Enterprise Linux Advanced Platform 5.3, Linux kernel 2.6.18-194.26.1.el5 #1 SMP [3] Creation of the ProcessBuilder object, redirecting the error stream, and starting it.

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  • Get consolidated results with following tables

    - by Ted
    I have a scenario. Here's my table structure is: ID LoginDate RemovalDate ---------------------------------------- 1 2009/08/01 NULL 2 2009/09/12 2010/01/02 3 2009/08/31 2009/10/29 4 2010/02/17 NULL 5 2009/10/18 2009/11/22 I want a consolidated results of how many ID's were not removed in a particular month. So the result set should be Date NotRemoved_ID -------------------------- 2009/08 2 2009/09 3 2009/10 3 [One ID got removed in 2009/10] 2010/02 2 [Two got removed in 2009/11 and 2010/01] Please help.

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  • can a program written in C be faster than one written in OCaml and translated to C?

    - by Ole Jak
    So I have some cool Image Processing algorithm. I have written it in OCaml. It performs well. I now I can compile it as C code with such command ocamlc -output-obj -o foo.c foo.ml (I have a situation where I am not alowed to use OCaml compiler to bild my programm for my arcetecture, I can use only specialy modified gcc. so I will compile that programm with sometyhing like gcc -L/usr/lib/ocaml foo.c -lcamlrun -lm -lncurses and Itll run on my archetecture.) I want to know in general case can a program written in C be faster than one written in OCaml and translated to C?

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  • Select Query Joined on Two Fields?

    - by btollett
    I've got a few tables in an access database: ID | LocationName 1 | Location1 2 | Location2 ID | LocationID | Date | NumProductsDelivered 1 | 1 | 12/10 | 3 2 | 1 | 01/11 | 2 3 | 1 | 02/11 | 2 4 | 2 | 11/10 | 1 5 | 2 | 12/10 | 1 ID | LocationID | Date | NumEmployees | EmployeeType 1 | 1 | 12/10 | 10 | 1 (=Permanent) 2 | 1 | 12/10 | 3 | 2 (=Temporary) 3 | 1 | 12/10 | 1 | 3 (=Support) 4 | 2 | 10/10 | 1 | 1 5 | 2 | 11/10 | 2 | 1 6 | 2 | 11/10 | 1 | 2 7 | 2 | 11/10 | 1 | 3 8 | 2 | 12/10 | 2 | 1 9 | 2 | 12/10 | 1 | 3 What I want to do is pass in the LocationID as a parameter and get back something like the following table. So, if I pass in 2 as my LocationID, I should get: Date | NumProductsDelivered | NumPermanentEmployees | NumSupportEmployees 10/10 | | 1 | 11/10 | 1 | 2 | 1 12/10 | 1 | 2 | 1 It seems like this should be a pretty simple query. I really don't even need the first table except as a way to fill in the combo box on the form from which the user chooses which location they want a report for. Unfortunately, everything I've done has resulted in me getting a lot more data than I should be getting. My confusion is in how to set up the join (presumably that's what I'm looking for here) given that I want both the date and locationID to be the same for each row in the result set. Any help would be much appreciated. Thanks.

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  • F# why my recursion is faster than Seq.exists?

    - by user38397
    I am pretty new to F#. I'm trying to understand how I can get a fast code in F#. For this, I tried to write two methods (IsPrime1 and IsPrime2) for benchmarking. My code is: // Learn more about F# at http://fsharp.net open System open System.Diagnostics #light let isDivisible n d = n % d = 0 let IsPrime1 n = Array.init (n-2) ((+) 2) |> Array.exists (isDivisible n) |> not let rec hasDivisor n d = match d with | x when x < n -> (n % x = 0) || (hasDivisor n (d+1)) | _ -> false let IsPrime2 n = hasDivisor n 2 |> not let SumOfPrimes max = [|2..max|] |> Array.filter IsPrime1 |> Array.sum let maxVal = 20000 let s = new Stopwatch() s.Start() let valOfSum = SumOfPrimes maxVal s.Stop() Console.WriteLine valOfSum Console.WriteLine("IsPrime1: {0}", s.ElapsedMilliseconds) ////////////////////////////////// s.Reset() s.Start() let SumOfPrimes2 max = [|2..max|] |> Array.filter IsPrime2 |> Array.sum let valOfSum2 = SumOfPrimes2 maxVal s.Stop() Console.WriteLine valOfSum2 Console.WriteLine("IsPrime2: {0}", s.ElapsedMilliseconds) Console.ReadKey() IsPrime1 takes 760 ms while IsPrime2 takes 260ms for the same result. What's going on here and how I can make my code even faster?

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  • SQL query doesn't get inserted

    - by Deejdd
    I've been trying to get my query to work for some time it runs but doesn't insert anything nor does it return any errors. The database connection is open and is successfuly connection. The Table is called errorlog and holds the following data - id (int autoincremental, Primary key, Unique) - exception (varchar) - time (DateTime) exception = String(error message) time = DateTime.Now Here's the code: public void insertError(string error, DateTime time) { SqlCeParameter[] sqlParams = new SqlCeParameter[] { new SqlCeParameter("@exception", error), new SqlCeParameter("@time", time) }; try { cmd = new SqlCeCommand(); cmd.Connection = connection; cmd.CommandType = CommandType.Text; cmd.CommandText = "INSERT INTO errorlog (exception, time) VALUES(@exception, @time)"; cmd.Parameters.AddRange(sqlParams); cmd.ExecuteNonQuery(); } catch (Exception e) { Console.WriteLine(e.Message); } } Any help would be appreciated, Thanks in advance. EDIT Removed quotes around @exception Heres the connection: protected DataController() { try { string appPath = System.IO.Path.GetDirectoryName(Assembly.GetAssembly(typeof(DataController)).CodeBase).Replace(@"file:\", "") + @"\"; string strCon = @"Data Source = " + appPath + @"Data\EasyShop.sdf"; connection = new SqlCeConnection(strCon); } catch (Exception e) { } connection.Open(); } Finally the way it gets called: public bool log(string msg, bool timestamp = true) { DataController dc = DataController.Instance(); dc.insertError(msg, DateTime.Today); return true; }

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  • mysql extra columns with same name from two tables

    - by salmane
    Table 1 has columns : entry_id user_id ... Table 2 has columns : entry_id user_id ... the user_id entry is not always the same so I would like to extract both of them so I can later on compare them in my script SELECT * FROM table1 as t1 INNER JOIN table2 as t2 on t1.entry_id=t2.entry_id WHERE t1.user_id='%s' I would like to extract t1.user_id and t2.user_id ...the problem is the result array has only user_id thank you

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  • Sort MySQL query result by a alphanumeric field

    - by Jason Shultz
    I'm querying a table in a db using php. one of the fields is a column called "rank" and has data like the following: none 1-bronze 2-silver 3-gold ... 10-ambassador 11-president I want to be able to sort the results based on that "rank" column. any results where the field is "none" get excluded, so those don't factor in. As you can already guess, right now the results are coming back like this: 1-bronze 10-ambassador 11-president 2-silver 3-gold Of course, I would like for it to be sorted so it is like the following: 1-bronze 2-silver 3-gold ... 10-ambassador 11-president Right now the query is being returned as an object. I've tried different sort options like natsort, sort, array_multisort but haven't got it to work the way I'm sure it can. I would prefer keeping the results in an object form if possible. I'm passing the data on to a view in the next step. although, it's perfectly acceptable to pass the object to the view and then do the work there. so it's not an issue after all. :) thank you for your help. i'm hoping I'm making sense.

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  • Time calculations with MySQL TIMEDIFF

    - by Oli
    Hi there, I have the following table: mysql> SELECT id,start1,stop1,start2,stop2 FROM times; +----+---------------------+---------------------+---------------------+---------------------+ | id | start1 | stop1 | start2 | stop2 | +----+---------------------+---------------------+---------------------+---------------------+ | 4 | 2010-04-23 08:05:00 | 2010-04-23 12:15:00 | 2010-04-23 12:45:00 | 2010-04-23 16:50:00 | | 2 | 2010-04-26 09:30:00 | 2010-04-26 12:10:00 | 2010-04-26 12:50:00 | 2010-04-26 16:50:00 | | 7 | 2010-04-28 08:45:00 | 2010-04-28 11:45:00 | 2010-04-28 13:10:00 | 2010-04-28 17:29:00 | | 6 | 2010-04-27 09:30:00 | 2010-04-27 12:15:00 | 2010-04-27 12:55:00 | 2010-04-27 18:44:00 | +----+---------------------+---------------------+---------------------+---------------------+ I want to sum total worktime and the difference to the "needed work hours". It works pretty well with the statement below, but for unknown reasons it doesn't work for id 6. start*/stop* fields are in format datetime. SELECT *, TIME_FORMAT(TIMEDIFF(totaltime,'08:24'),'%H:%i') AS diff, totaltime > '08:24' AS redorgreen FROM ( SELECT DATE_FORMAT(start1,'%a %e. %M %Y') AS date, TIME_FORMAT(SUM(TIMEDIFF(stop1,start1) + TIMEDIFF(stop2,start2)),'%H:%i') AS totaltime, TIME_FORMAT(start1,'%H:%i') AS start1, TIME_FORMAT(stop1,'%H:%i') AS stop1, TIME_FORMAT(start2,'%H:%i') AS start2, TIME_FORMAT(stop2,'%H:%i') AS stop2, id as id FROM times GROUP BY id ASC ) AS somethingwedontneed; This is the result: select id, TIME_FORMAT(SUM(TIMEDIFF(stop1,start1) + TIMEDIFF(stop2,start2)),'%H:%i') AS totaltime from times group by id; +----+-----------+ | id | totaltime | +----+-----------+ | 2 | 06:40 | | 4 | 08:15 | | 6 | NULL | | 7 | 07:19 | +----+-----------+ Thanks in advance for every hint.

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  • how to compare the values inside a table in sql

    - by Ranjana
    how to compare the values of same table(say for eg: Order table) each and every time the record get inserted , if the record with same values get inserted already in same table i should not insert the new record with same values. how to do that exactly in sql server 2008

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  • How can I get a list of the most recent tags in a wordpress database?

    - by Failpunk
    I am not familiar with the wordpress schema at all and I need to get back a list, or array of the most recent tags from any post in the wordpress database. I just need the data available on the home page so I can then manipulate it. All the functions seem to be designed to work on a per-post basis. (Wordpress really makes me feel sorry for frequent wordpress programmers.)

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  • mysql count(*) left join group by - the number of files in a folder

    - by Flavius
    Hi I have the following tables CREATE TABLE `files` ( `fileid` int(11) NOT NULL AUTO_INCREMENT, `filename` varchar(255) NOT NULL, `filesize` int(11) NOT NULL, `folder` int(11) NOT NULL, PRIMARY KEY (`fileid`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8; CREATE TABLE `folders` ( `directoryid` int(11) NOT NULL AUTO_INCREMENT, `directoryname` varchar(255) NOT NULL, PRIMARY KEY (`directoryid`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8; How to get a list of all folders and the number of files they hold, including folders who have no (zero) files? Recursion must not be taken into account. Found it select folders.directoryid, folders.directoryname, count(files.fileid) as no_files from folders left join files on files.folder = folders.directoryid group by folders.directoryid, folders.directoryname I hope it will help someone.

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  • PHP : flatten array - fastest way?

    - by Industrial
    Is there any fast way to flatten an array and select subkeys ('key'&'value' in this case) without running a foreach loop, or is the foreach always the fastest way? Array ( [0] => Array ( [key] => string [value] => a simple string [cas] => 0 ) [1] => Array ( [key] => int [value] => 99 [cas] => 0 ) [2] => Array ( [key] => array [value] => Array ( [0] => 11 [1] => 12 ) [cas] => 0 ) ) To: Array ( [int] => 99 [string] => a simple string [array] => Array ( [0] => 11 [1] => 12 ) )

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  • What is microbenchmarking?

    - by polygenelubricants
    I've heard this term used, but I'm not entirely sure what it means, so: What DOES it mean and what DOESN'T it mean? What are some examples of what IS and ISN'T microbenchmarking? What are the dangers of microbenchmarking and how do you avoid it? (or is it a good thing?)

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  • Query table value aliasing in Oracle SQL

    - by Strata
    I have a homework assignment in SQL for Oracle 10g where I have to apply union to two different select statements, to return two columns. I need the values of each cell under vendor_state to indicate CA and every other value in another state to return "Outside CA", to indicate they're elsewhere. I applied the union and produced the two columns and the listings for CA, but many other state IDs were listed and I couldn't find an explanation for how to change the actual values in the query itself. Eventually, I stumbled on an answer, but I can't explain why this works. The code is as follows: SELECT vendor_name, vendor_state FROM vendors WHERE vendor_state IN 'CA' UNION SELECT vendor_name, 'Outside CA' AS vendor_state FROM vendors WHERE vendor_state NOT IN 'CA' ORDER BY vendor_name This gives me the exact answer I need, but I don't know why the aliasing in the second select statement can behave this way....no explanation is given in my textbook and nothing I've read indicates that column aliasing can be done like this. But, by switching the column name and the alias value, I have replaced the value being returned rather than the column name itself...I'm not complaining about the result, but it would help if I knew how I did it.

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