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  • Help need to with MySQL query to join data spanning multiple tables and use data as column names

    - by gurun8
    I need a little help putting together a SQL query that will give me the following resultsets: and The data model looks like this: The tricky part for me is that the columns to the right of the "Product" in the resultset aren't really columns in the database but rather key/value pairs spanned across the data model. Table data is as follows: My apologies in advance for the image heavy question and the image quality. This just seemed like the easiest way to convey the information. It'll probably take someone less time to write the query statement to achieve the results than it did for me to assemble this question. By the way, the "product_option" table image is truncated but it illustrated the general idea of the data structure. The MySQL server version is 5.1.45.

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  • Help needed with MySQL query to join data spanning multiple tables with data used as column names

    - by gurun8
    I need a little help putting together a SQL query that will give me the following resultsets: and The data model looks like this: The tricky part for me is that the columns to the right of the "Product" in the resultset aren't really columns in the database but rather key/value pairs spanned across the data model. Table data is as follows: My apologies in advance for the image heavy question and the image quality. This just seemed like the easiest way to convey the information. It'll probably take someone less time to write the query statement to achieve the results than it did for me to assemble this question. By the way, the "product_option" table image is truncated but it illustrated the general idea of the data structure. The MySQL server version is 5.1.45.

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  • Is there any way to simplify a verbose SQL INSERT INTO(..) query?

    - by Soundar Rajan
    I have a table with one id (autonumber) field and 50 other fields. The table is normalized, these are 50 material properties etc. I want to copy a record from this table into the same table - only the autoincrement id will be different. The query I am using now is INSERT INTO tableName (field1,field2,....field50) SELECT field1,field2,....field50 from tableName WHERE autoid=1234; Note that I have to type in ALL the 50 field names, twice! Is there any way to shorten this query so I don't have to type all of them? Thanks.

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  • Mysql: i need to get the offset of a item in a query.

    - by user305270
    Mysql: i need to get the offset of a item in a query. I have a image gallery: this show 6 image per stack, so when i request image 22 it shows images from 18 to 24. It should first get the offset of the image 22, then get the images from 18 to 24. Another example: i request the image number 62(and offset 62), it will select images with offset from 60 to 66. Is possible with a single query? Thanks ;)

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  • STOP ERASING MY QUESTIONS! - VIEWING FIRST_ROWS BEFORE QUERY COMPLETES (RE-VISITED)

    - by Frank Developer
    OK, so say I have a table with 500K rows, then I ad-hoc query with unsupported indexing which requires a full table scan. I would like to immediately view the first rows returned while the full table scan continues. Then I want to scroll thru the next results. In the meantime, I would like to display the progress of the table scan, example: "SEARCHING.. FOUND 23 OF 500,000 ROWS SO FAR". If I scroll too far ahead, I want to display a message like: "REACHED LAST ROW IN LOOK-AHEAD BUFFER.. QUERY HAS NOT COMPLETED".. Can this be done? Maybe like: spawn/exec, declare scroll cursor, open, fetch, etc.?

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  • Maximum number of files one ext3 directory while still getting acceptable performance?

    - by knorv
    I have an application writing to an ext3 directory which over time has grown to roughly three million files. Needless to say, reading the file listing of this directory is unbearably slow. I don't blame ext3. The proper solution would have been to let the directory write to sub-directories such as ./a/b/c/abc.ext rather than just ./abc.ext. I'm changing to such a sub-directory structure and my question is simply: roughly how many files should I expect to store in one ext3 directory while still getting acceptable performance? Or in other words; assuming that I need to store three million files in the structure, how many levels deep should the ./a/b/c/abc.ext structure be? Obviously this is a question that cannot be answered exactly, but I'm looking for a ball park estimate.

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  • Is it OK to open a DB4o file for query, insert, update multiple times?

    - by Khnle
    This is the way I am thinking of using DB4o. When I need to query, I would open the file, read and close: using (IObjectContainer db = Db4oFactory.OpenFile(Db4oFactory.NewConfiguration(), YapFileName)) { try { List<Pilot> pilots = db.Query<Pilot>().ToList<Pilot>(); } finally { try { db.Close(); } catch (Exception) { }; } } At some later time, when I need to insert, then using (IObjectContainer db = Db4oFactory.OpenFile(Db4oFactory.NewConfiguration(), YapFileName)) { try { Pilot pilot1 = new Pilot("Michael Schumacher", 100); db.Store(pilot1); } finally { try { db.Close(); } catch (Exception) { }; } } In this way, I thought I will keep the file more tidy by only having it open when needed, and have it closed most of the time. But I keep getting InvalidCastException Unable to cast object of type 'Db4objects.Db4o.Reflect.Generic.GenericObject' to type 'Pilot' What's the correct way to use DB4o?

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  • SOAP - Why do I need to query for the values for an update?

    - by Phill Pafford
    I'm taking over a project and wanted to understand if this is common practice using SOAP. The process that is currently in place I have to query all the values before I do an update cause I need to pass back all the values that are not being updated. Does this sound right? Example Values: fname=phill lname=pafford address=123 main phone:222-555-1212 So if I just wanted to update the phone number I need to query for the record, get all the values and submit these values for an update. Example Update Values: fname=phill lname=pafford address=123 main phone:111-555-1212 I just want to know if this is common practice or should I change the functionality of this?

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  • How to solve the performance decay of a VB.NET 1.1 application?

    - by marco.ragogna
    I have single-thread windows form application written with VB.NET and targeting Framework 1.1. The software communicates with external boards through a serial interface, and it mainly consist of a state machine that run some tests, driven in a loop done with a Timer and an Interval of 50ms. The feedback on the user interface is done through some custom events raised during the tests. The problem that is driving me crazy is that the performance slightly decrease over time, and in particular after 1200/1300 test operations. The memory occupied does not increase over time, it is only the CPU that seems interested by this problem. The strange thing is that, targeting framework 2.0 and using the same identical code, I do not have this problem. I know that is difficult without looking at the code, but do you have suggestions how can I approach the problem?

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  • Chaning coding style due to Android GC performance, how far is too far?

    - by Benju
    I keep hearing that Android applications should try to limit the number of objects created in order to reduce the workload on the garbage collector. It makes sense that you may not want to created massive numbers of objects to track on a limited memory footprint, for example on a traditional server application created 100,000 objects within a few seconds would not be unheard of. The problem is how far should I take this? I've seen tons of examples of Android applications relying on static state in order supposedly "speed things up". Does increasing the number of instances that need to be garbage collected from dozens to hundreds really make that big of a difference? I can imagine changing my coding style to now created hundreds of thousands of objects like you might have on a full-blown Java-EE server but relying on a bunch of static state to (supposedly) reduce the number of objects to be garbage collected seems odd. How much is it really necessary to change your coding style in order to create performance Android apps?

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  • Which SQL query is faster? Filter on Join criteria or Where clause?

    - by Jon Erickson
    Compare these 2 queries. Is it faster to put the filter on the join criteria or in the were clause. I have always felt that it is faster on the join criteria because it reduces the result set at the soonest possible moment, but I don't know for sure. I'm going to build some tests to see, but I also wanted to get opinions on which would is clearer to read as well. Query 1 SELECT * FROM TableA a INNER JOIN TableXRef x ON a.ID = x.TableAID INNER JOIN TableB b ON x.TableBID = b.ID WHERE a.ID = 1 /* <-- Filter here? */ Query 2 SELECT * FROM TableA a INNER JOIN TableXRef x ON a.ID = x.TableAID AND a.ID = 1 /* <-- Or filter here? */ INNER JOIN TableB b ON x.TableBID = b.ID

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  • When does a MySQL Query actually execute in PHP?

    - by MJB
    This sounds like a really simple question, but I am new to PHP. If I have a statement like this: $r =& $db->query("insert into table (col1, col2) values (10, 20)"); Do I have to still execute it, or does it get executed when I reference it? I have another case where I have a select query, which seems logically to run only when I call fetchrow, but the code I am presented with (to fix) does not call execute or fetch.I would have expected it to, so I cannot tell if it is just that I don't get it, or that the missing execute statement is the problem. It also does not insert the record, but it does not throw an error I can find. Also, I am a little confused by the =& notation. I looked it up on google, and found a few mentions of it, but I am still not clear on it. Thanks.

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  • java System.nanoTime is really slow. Is it possible to implement a high performance java profiler?

    - by willpowerforever
    I did a test and found the overhead of a function call to System.nanoTime() is at least 500 ns on my machine. Seemed that it is very hard to have a high performance java profiler. For enterprise software, suppose a function takes about 350 seconds and has 12,500,000,000 times of method calls. Therefore, the number of calls to System.nanoTime() is: 12,500,000,000 * 2 = 25,000,000,000 (one for start timestamp, one for end timestamp) And the overhead of System.nanoTime in total is: 500 ns * 25,000,000,000 = 500 * 25000 s = 12500000s. Note: all data from real case. Any better way to acquire the timestamp?

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  • Can somone help fix up my simple regex query, please?

    - by Pure.Krome
    Hi folks, yep - another noob regex query, which I can't seem to get. I'm trying to get all matches for the string foo.mydomain.com/ or foo.mydomain.com:1234/ or foo.mydomain.com:<random port>/ but any other paths do not match, ie. foo.mydomain.com/bar or foo.mydomain.com/bar/pewpew I tried to use: foo.mydomain.com(.*)/$ ( starts with anything, then foo.mydomain.com, then any thing after that .. until a slash. then end. (this search query is anchored to the end of the line). but that doesn't work. It doesn't match when i pass in foo.mydomain.com:1234 but it correct says foo.mydomain.com/bar/pewpew is not a match (as expected). any ideas?

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  • How do I display a field's hidden characters in the result of a query in Oracle?

    - by Chris Williams
    I have two rows that have a varchar column that are different according to a Java .equals(). I can't easily change or debug the Java code that's running against this particular database but I do have access to do queries directly against the database using SQLDeveloper. The fields look the same to me (they are street addresses with two lines separated by some new line or carriage feed/new line combo). Is there a way to see all of the hidden characters as the result of a query?I'd like to avoid having to use the ascii() function with substr() on each of the rows to figure out which hidden character is different. I'd also accept some query that shows me which character is the first difference between the two fields.

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  • Is there limit of "join" or the "where" or length of SQL query ?

    - by Chetan sharma
    Actually i was trying to get data from elgg database based on multiple joins. It generated very big query with lots of JOIN statements and query never respond back. SELECT distinct e.* from test_entities e JOIN test_metadata m1 on e.guid = m1.entity_guid JOIN test_metastrings ms1 on ms1.id = m1.name_id JOIN test_metastrings mv1 on mv1.id = m1.value_id JOIN test_objects_entity obj on e.guid = obj.guid JOIN test_metadata m2 on e.guid = m2.entity_guid JOIN test_metastrings ms2 on ms2.id = m2.name_id JOIN test_metastrings mv2 on mv2.id = m2.value_id JOIN test_metadata m3 on e.guid = m3.entity_guid JOIN test_metastrings ms3 on ms3.id = m3.name_id JOIN test_metastrings mv3 on mv3.id = m3.value_id JOIN test_metadata m4 on e.guid = m4.entity_guid JOIN test_metastrings ms4 on ms4.id = m4.name_id JOIN test_metastrings mv4 on mv4.id = m4.value_id JOIN test_metadata m5 on e.guid = m5.entity_guid JOIN test_metastrings ms5 on ms5.id = m5.name_id JOIN test_metastrings mv5 on mv5.id = m5.value_id JOIN test_metadata m6 on e.guid = m6.entity_guid JOIN test_metastrings ms6 on ms6.id = m6.name_id JOIN test_metastrings mv6 on mv6.id = m6.value_id where ms1.string='expire_date' and mv1.string <= 1272565800 and ms2.string='homecity' and mv2.string LIKE "%dasf%" and ms3.string='schoolname' and mv3.string LIKE "%asdf%" and ms4.string='award_amount' and mv4.string <= 123 and ms5.string='no_of_awards' and mv5.string <= 7 and ms6.string='avg_rating' and mv6.string <= 2 and e.type = 'object' and e.subtype = 5 and e.site_guid = 1 and (obj.title like '%asdf%') OR (obj.description like '%asdf%') and ( (e.access_id = -2 AND e.owner_guid IN ( SELECT guid_one FROM test_entity_relationships WHERE relationship='friend' AND guid_two=5 )) OR (e.access_id IN (2,1) OR (e.owner_guid = 5) OR ( e.access_id = 0 AND e.owner_guid = 5 ) ) and e.enabled='yes') and ( (m1.access_id = -2 AND m1.owner_guid IN ( SELECT guid_one FROM test_entity_relationships WHERE relationship='friend' AND guid_two=5 )) OR (m1.access_id IN (2,1) OR (m1.owner_guid = 5) OR ( m1.access_id = 0 AND m1.owner_guid = 5 ) ) and m1.enabled='yes') and ( (m2.access_id = -2 AND m2.owner_guid IN ( SELECT guid_one FROM test_entity_relationships WHERE relationship='friend' AND guid_two=5 )) OR (m2.access_id IN (2,1) OR (m2.owner_guid = 5) OR ( m2.access_id = 0 AND m2.owner_guid = 5 ) ) and m2.enabled='yes') and ( (m3.access_id = -2 AND m3.owner_guid IN ( SELECT guid_one FROM test_entity_relationships WHERE relationship='friend' AND guid_two=5 )) OR (m3.access_id IN (2,1) OR (m3.owner_guid = 5) OR ( m3.access_id = 0 AND m3.owner_guid = 5 ) ) and m3.enabled='yes') and ( (m4.access_id = -2 AND m4.owner_guid IN ( SELECT guid_one FROM test_entity_relationships WHERE relationship='friend' AND guid_two=5 )) OR (m4.access_id IN (2,1) OR (m4.owner_guid = 5) OR ( m4.access_id = 0 AND m4.owner_guid = 5 ) ) and m4.enabled='yes') and ( (m5.access_id = -2 AND m5.owner_guid IN ( SELECT guid_one FROM test_entity_relationships WHERE relationship='friend' AND guid_two=5 )) OR (m5.access_id IN (2,1) OR (m5.owner_guid = 5) OR ( m5.access_id = 0 AND m5.owner_guid = 5 ) ) and m5.enabled='yes') and ( (m6.access_id = -2 AND m6.owner_guid IN ( SELECT guid_one FROM test_entity_relationships WHERE relationship='friend' AND guid_two=5 )) OR (m6.access_id IN (2,1) OR (m6.owner_guid = 5) OR ( m6.access_id = 0 AND m6.owner_guid = 5 ) ) and m6.enabled='yes') order by obj.title limit 0, 10 this is the query that i am running.

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  • Does the number of busy worker threads in the CLR ThreadPool affect performance of I/O threads?

    - by andrej351
    We have a Windows Service which hosts a number of WCF services and, in an unrelated part of the app, makes extensive use of the TPL Task class to asynchronously do relatively short bits of work. It is my understanding that WCF uses managed I/O threads from the ThreadPool to execute requests. I noticed that after deploying a feature which significantly raised the applications use of Tasks, and as such the use of ThreadPool worker threads as well, performance of a couple of web services has become very slow. We're talking minutes instead of less than a second. The number of Tasks actually trying to run at any one time can range between 20 and 1000, which makes me think that any new (last in) work needing some CPU time could be forced to wait for quite some time. Does the (in my case extremely large) number of busy ThreadPool worker threads affect the ThreadPool's managed I/O threads? Or could these two be connected in any way? Thanks!

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  • How do I get query string value from script path?

    - by TruMan1
    I am adding my Javsacript file in pages with different query strings in the script path like this: Page1: <script type="text/javascript" src="file.js?abc=123"></script> Page2: <script type="text/javascript" src="file.js?abc=456"></script> Page3: <script type="text/javascript" src="file.js?abc=789"></script> In my Javascript file, how can I get the value of the "abc" param? I tried using window.location for this, but that does not work. In case it helps, below is a function I use to find the value of a query string param: function getQuerystring(key, defaultValue) { if (defaultValue == null) defaultValue = ""; key = key.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]"); var regex = new RegExp("[\\?&]" + key + "=([^&#]*)"); var qs = regex.exec(window.location.href); if (qs == null) return defaultValue; else return qs[1]; }

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  • How to show the elapsed time on a long Query execution?

    - by Salvador
    i need to show a popup window before the a query execution, and close that windows when the query ends. actually i do something like this var frm : tFrmPopupElapsed; // this form have a ttimer and a tlabel to show the elapsed time //but the tlabel is not updated, i tried using update; and refresh; but nothing happens //the timer is enabled. begin frm:=tform.create(nil); frm.Init;//this procedure set the timer to enabled:=true try frm.Show(); ExecuteMyVeryLongQuery(); finally frm.Close; end; end; wich is the best way using a ttimer? a Tthread ? thanks in advance.

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  • How to salvage SQL server 2008 query from KILLED/ROLLBACK state without waiting half a day?

    - by littlegreen
    I have a stored procedure that inserts batches of millions of rows, emerging from a certain query, into an SQL database. It has one parameter selecting the batch; when this parameter is omitted, it will gather a list of batches and recursively call itself, in order to iterate over batches. In (pseudo-)code, it looks something like this: CREATE PROCEDURE spProcedure AS BEGIN IF @code = 0 BEGIN ... WHILE @@Fetch_Status=0 BEGIN EXEC spProcedure @code FETCH NEXT ... INTO @code END END ELSE BEGIN -- Disable indexes ... INSERT INTO table SELECT (...) -- Enable indexes ... Now it can happen that this procedure is slow, for whatever reason: it can't get a lock, one of the indexes it uses is misdefined or disabled. In that case, I want to be able kill the procedure, truncate and recreate the resulting table, and try again. However, when I try and kill the procedure, the process frequently oozes into a KILLED/ROLLBACK state from which there seems to be no return. From Google I have learned to do an sp_lock, find the spid, and then kill it with KILL <spid>. But when I try to kill it, it tells me SPID 75: transaction rollback in progress. Estimated rollback completion: 0%. Estimated time remaining: 554 seconds. I did find a forum message hinting that another spid should be killed before the other one can start a rollback. But that didn't work for me either, plus I do not understand, why that would be the case... could it be because I am recursively calling my own stored procedure? (But it should be having the same spid, right?) In any case, my process is just sitting there, being dead, not responding to kills, and locking the table. This is very frustrating, as I want to go on developing my queries, not waiting hours on my server sitting dead while pretending to be finishing a supposed rollback. Is there some way in which I can tell the server not to store any rollback information for my query? Or not to allow any other queries to interfere with the rollback, so that it will not take so long? Or how to rewrite my query in a better way, or how kill the process successfully without restarting the server?

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  • Does the order of case in Switch statement can vary the performance?

    - by Bipul
    Let say I have a switch statement as below Switch(alphabet){ case "f": //do something break; case "c": //do something break; case "a": //do something break; case "e": //do something break; } Now suppose I know that the frequency of having Alphabet e is highest followed by a, c and f respectively. So, I just restructured the case statement order and made them as follows. Switch(alphabet){ case "e": //do something break; case "a": //do something break; case "c": //do something break; case "f": //do something break; } Will the second Switch statement better perform(means faster) than the first switch statement? If yes and if in my program I need to call this switch statement say many times, will that be a substantial improvement? Or if not in any how can I use my frequency knowledge to improve the performance? Thanks

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  • How to do query auto-completion/suggestions in Lucene?

    - by Mat Mannion
    I'm looking for a way to do query auto-completion/suggestions in Lucene. I've Googled around a bit and played around a bit, but all of the examples I've seen seem to be setting up filters in Solr. We don't use Solr and aren't planning to move to using Solr in the near future, and Solr is obviously just wrapping around Lucene anyway, so I imagine there must be a way to do it! I've looked into using EdgeNGramFilter, and I realise that I'd have to run the filter on the index fields and get the tokens out and then compare them against the inputted Query... I'm just struggling to make the connection between the two into a bit of code, so help is much appreciated! To be clear on what I'm looking for (I realised I wasn't being overly clear, sorry) - I'm looking for a solution where when searching for a term, it'd return a list of suggested queries. When typing 'inter' into the search field, it'll come back with a list of suggested queries, such as 'internet', 'international', etc.

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  • MySQL Query, how to group and count in one row ?

    - by Akarun
    Hi All, To simplify, I have tree tables: products, products-vs-orders, orders products fields : 'ProductID', 'Name', 'isGratis', ... products-vs-orders fields : 'ProductID', 'OrderID' orders fields : 'OrderID', 'Title', ... Actually, I have a query like this: SELECT orders.OrderID, orders.Title, COUNT(`products`.`isGratis`) AS "Quantity", `products`.`isGratis` FROM `orders`, `products-vs-orders`, `products` WHERE `orders`.`OrderID` = `products-vs-orders`.`OrderID` AND `products-vs-orders`.`ProductID` = `products`.`ProductID` GROUP BY `products`.`PackID`, `products`.`isGratis` This query works and return this surch of result: OrderID, Title, Quantity, isGratis 1 My Order 20 0 1 My Order 3 1 2 An other 8 0 2 An other 1 1 How can I retrieve the count of products 'gratis' and 'paid' in to separate cols ? OrderID, Title, Qt Paid, Qt Gratis 1 My Order 20 3 2 An other 8 1 Thanks for your help

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  • How do I use comma-separated-value file received from a URL query in Objective-c?

    - by chiemekailo
    How do I use comma-separated-value file received from a URL query in Objective-c? when I query the URL I get csv such as "OMRUAH=X",20.741,"3/16/2010","1:52pm",20.7226,20.7594. How do I capture and use this for my application? My problem is creating/initializing that NSString object in the first place. An example is this link "http://download.finance.yahoo.com/d/quotes.csv?s=GBPEUR=X&f=sl1d1t1ba&e=.csv" which returns csv. I dont know how to capture this as an object since I cannot use an NSXMLParser object.

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