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  • Exceptions handling in SQL?

    - by Vineet
    Is there any way to handle exceptions in sql(ORACLE 9i)? Since I was trying to divide values of a column that contains both numbers and literals ,I need to fetch out only numbers from it ,as if it divisible by any number then its number else if contains literals it would not get divided it will generate error. how to handle those errors? Please suggest!!

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  • What is the time complexity of LinkedList.getLast() in Java?

    - by i.
    I have a private LinkedList in a Java class & will frequently need to retrieve the last element in the list. The lists need to scale, so I'm trying to decide whether I need to keep a reference to the last element when I make changes (to achieve O(1)) or if the LinkedList class does that already with the getLast() call. What is the big-O cost of LinkedList.getLast() and is it documented? (i.e. can I rely on this answer or should I make no assumptions & cache it even if it's O(1)?)

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  • PHP Try and Catch for SQL Insert

    - by meme
    I have a page on my website (high traffic) that does an insert on every page load. I am curious of the fastest and safest way to (catch an error) and continue if the system is not able to do the insert into MySQL. Should I use try/catch or die or something else. I want to make sure the insert happens but if for some reason it can't I want the page to continue to load anyway. ... $db = mysql_select_db('mobile', $conn); mysql_query("INSERT INTO redirects SET ua_string = '$ua_string'") or die('Error #10'); mysql_close($conn); ...

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  • which one is a faster/better sql practice?

    - by artsince
    Suppose I have a 2 column table (id, flag) and id is sequential. I expect this table to contain a lot of records. I want to periodically select the first row not flagged and update it. Some of the records on the way may have already been flagged, so I want to skip them. Does it make more sense if I store the last id I flagged and use it in my select statement, like select * from mytable where id > my_last_id order by id asc limit 1 or simply get the first unflagged row, like: select * from mytable where flagged = 'F' order by id asc limit 1 Thank you!

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  • MySQL: List rows who have one but not another many-to-many relationship

    - by Svish
    Not quite sure how to ask or define this, but can't figure it out. I have three tables like this: persons person_id, first_name, last_name hobbies hobby_id, name persons_hobbies person_id, hobby_id I need to make two lists. Persons that have both hobby A and B, and persons that have hobby A but not B. How can I write these two queries? Can't figure out how to do this with joining and all...

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  • Start all tab's activities for pre-cache

    - by Pentium10
    I have a TabActivity with three tabs defined. The first tab is light-weight and renders in acceptable time. But the 2nd and 3rd tab, does need a couple of seconds to get visually rendered, after I click them. I would like to launch them, after I've loaded my first tab, in background for pre-cache. Once they are loaded, I can switch quickly between them. So I am wondering how can I launch the 2nd and 3rd tab. They are intents loaded in the view area.

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  • Help optimizing a query with 16 subqueries

    - by Webnet
    I have indexes/primaries on all appropriate ID fields for each type. I'm wondering though how I could make this more efficient. It takes a while to load the page with only 15,000 rows and that'll quickly grow to 500k. The $whereSql variable simply has a few more parameters for the main ebay_archive_listing table. NOTE: This is all done in a single query because I have ASC/DESC sorting for each subquery value. NOTE: I've converted some of the sub queries to INNER JOIN's SELECT product_master.product_id, ( SELECT COUNT(listing_id) FROM ebay_archive_product_listing_assoc '.$listingCountJoin.' WHERE ebay_archive_product_listing_assoc.product_id = product_master.product_id) as listing_count, sku, type_id, ( SELECT AVG(ebay_archive_listing.current_price) FROM ebay_archive_listing INNER JOIN ebay_archive_product_listing_assoc ON ( ebay_archive_product_listing_assoc.listing_id = ebay_archive_listing.id AND ebay_archive_product_listing_assoc.product_id = product_master.product_id ) WHERE '.$whereSql.' AND ebay_archive_listing.current_price > 0 ) as average_bid_price, ( SELECT AVG(ebay_archive_listing.buy_it_now_price) FROM ebay_archive_listing INNER JOIN ebay_archive_product_listing_assoc ON ( ebay_archive_product_listing_assoc.listing_id = ebay_archive_listing.id AND ebay_archive_product_listing_assoc.product_id = product_master.product_id ) WHERE '.$whereSql.' AND ebay_archive_listing.buy_it_now_price > 0 ) as average_buyout_price, ( SELECT MIN(ebay_archive_listing.current_price) FROM ebay_archive_listing INNER JOIN ebay_archive_product_listing_assoc ON ( ebay_archive_product_listing_assoc.listing_id = ebay_archive_listing.id AND ebay_archive_product_listing_assoc.product_id = product_master.product_id ) WHERE '.$whereSql.' AND ebay_archive_listing.current_price > 0 ) as lowest_bid_price, ( SELECT MAX(ebay_archive_listing.current_price) FROM ebay_archive_listing INNER JOIN ebay_archive_product_listing_assoc ON ( ebay_archive_product_listing_assoc.listing_id = ebay_archive_listing.id AND ebay_archive_product_listing_assoc.product_id = product_master.product_id ) WHERE '.$whereSql.' AND ebay_archive_listing.current_price > 0 ) as highest_bid_price, ( SELECT MIN(ebay_archive_listing.buy_it_now_price) FROM ebay_archive_listing INNER JOIN ebay_archive_product_listing_assoc ON ( ebay_archive_product_listing_assoc.listing_id = ebay_archive_listing.id AND ebay_archive_product_listing_assoc.product_id = product_master.product_id ) WHERE '.$whereSql.' AND ebay_archive_listing.current_price > 0 ) as lowest_buyout_price, ( SELECT MAX(ebay_archive_listing.buy_it_now_price) FROM ebay_archive_listing INNER JOIN ebay_archive_product_listing_assoc ON ( ebay_archive_product_listing_assoc.listing_id = ebay_archive_listing.id AND ebay_archive_product_listing_assoc.product_id = product_master.product_id ) WHERE '.$whereSql.' AND ebay_archive_listing.current_price > 0 ) as highest_buyout_price, round((( SELECT COUNT(ebay_archive_listing.id) FROM ebay_archive_listing INNER JOIN ebay_archive_product_listing_assoc ON ( ebay_archive_product_listing_assoc.listing_id = ebay_archive_listing.id AND ebay_archive_product_listing_assoc.product_id = product_master.product_id ) WHERE '.$whereSql.' AND ebay_archive_listing.status_id = 2 ) / ( SELECT COUNT(listing_id) FROM ebay_archive_product_listing_assoc '.$listingCountJoin.' WHERE ebay_archive_product_listing_assoc.product_id = product_master.product_id ) * 100), 1) as sold_percent FROM product_master '.$joinSql.' WHERE product_master.product_id IN ( SELECT product_id FROM ebay_archive_product_listing_assoc INNER JOIN ebay_archive_listing ON ( ebay_archive_listing.id = ebay_archive_product_listing_assoc.listing_id AND '.$whereSql.' ) )

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  • Replace BIT values with some text

    - by nihi_l_ist
    I have a BIT column with gender (0,1) and want to replace 0 and 1 in the resulting view with the words "man" and "woman". Can i do this right in the view with some system finction or i have to write my own function to do that?

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  • Delete from empty table taking forver

    - by Will
    Hello, I have an empty table that previously had a large amount of rows. The table has about 10 columns and indexes on many of them, as well as indexes on multiple columns. DELETE FROM item WHERE 1=1 This takes approximately 40 seconds to complete SELECT * FROM item this takes 4 seconds. The execution plan of SELECT * FROM ITEM shows the following; SQL> select * from midas_item; no rows selected Elapsed: 00:00:04.29 Execution Plan ---------------------------------------------------------- 0 SELECT STATEMENT Optimizer=CHOOSE (Cost=19 Card=123 Bytes=73 80) 1 0 TABLE ACCESS (FULL) OF 'MIDAS_ITEM' (Cost=19 Card=123 Byte s=7380) Statistics ---------------------------------------------------------- 0 recursive calls 0 db block gets 5263 consistent gets 5252 physical reads 0 redo size 1030 bytes sent via SQL*Net to client 372 bytes received via SQL*Net from client 1 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 0 rows processed any idea why these would be taking so long and how to fix it would be greatly appreciated!!

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  • How to set up a specific registration on Database

    - by ymorenz
    I'm creating a database so I can access names of people from a university. But I would like to create a registration ID for each person like 1012607, of which the first 2 numbers would be the year (11 for 2011) and the third digit would be the semester they registered (1 in the beginning of the year and 2 in the end of the year). The other 4 digits would be incremental. I don't know how to code a prefixed number in MySQL that can change only the last 4 digits and after a year change the first 2 digits every time you have a new registration. Can someone please help me?

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  • What does `?` stand for in SQL?

    - by user295189
    I have this SQL by a programmer: $sql = " INSERT INTO `{$database}`.`table` ( `my_id`, `xType`, `subType`, `recordID`, `textarea` ) VALUES ( {$my_id}, ?xType, ?subType, {$recordID}, ?areaText ) "; My question is why is he using ? before values? How do I see what values are coming in? I did echo and it shows ?xType as ?xType. No values. What does ? stand for in SQL?

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  • SQL - Link to more table information

    - by BioXhazard
    I have a datagrid with 3 of 5 fields from a SQL table. The first databound was changed to an asp:hyperlink so the field can be clicked. What I want to do is, when the user clicks an object in the field, it sends the ID to another page. From there, it uses the request in order to display the required information which is found in the same SQL table. For example: User clicks on a cell in the first column, it brings them to a page with more information on that cell.

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  • Show the specific field on mysql table based on active date

    - by mrjimoy_05
    Suppose that I have 3 tables: A) Table UsrHeader ----------------- UsrID | UsrName ----------------- 1 | Abc 2 | Bcd B) Table UsrDetail ------------------------------- UsrID | UsrLoc | Date ------------------------------- 1 | LocA | 10 Aug 2012 1 | LocB | 15 Aug 2012 2 | LocA | 10 Aug 2012 C) Table Trx ----------------------------- TrxID | TrxDate | UsrID ----------------------------- 1 | 10 Aug 2012 | 1 2 | 16 Aug 2012 | 1 3 | 11 Aug 2012 | 2 What I want to do is to show the table like: --------------------------------------- TrxID | TrxDate | UsrID | UsrLoc --------------------------------------- 1 | 10 Aug 2012 | 1 | LocA 2 | 16 Aug 2012 | 1 | LocB 3 | 11 Aug 2012 | 2 | LocA Notice that there is one user but different location. That's based on the UsrDetail table that the user on a specified date has moved to another location. So, it should be show the user specific location on that date on every transaction. I have try this code but it is no luck: SELECT trx.TrxID, trx.TrxDate, trx.UsrID, User.UsrName, User.UsrLoc FROM trx INNER JOIN ( SELECT UsrHeader.UsrID, UsrHeader.UsrName, UserDetail.UsrLoc FROM UsrHeader INNER JOIN ( SELECT UsrDetail.UsrID, UsrDetail.UsrLoc, UsrDetail.Date FROM UsrDetail ) AS UserDetail ON UserDetail.UsrID = UsrHeader.UsrID ) AS User ON User.UsrID = trx.UsrID AND trx.TrxDate >= User.Date How to do that? Thanks..

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  • What's wrong with this inner query (MySQL)...

    - by stuboo
    ...besides the fact that I am a total amateur? My table is set up like this: CREATE TABLE `messages` ( `id` int(6) unsigned NOT NULL AUTO_INCREMENT, `patient_id` int(6) unsigned NOT NULL, `message` varchar(255) NOT NULL, `savedate` int(10) unsigned NOT NULL, `senddate` int(10) unsigned NOT NULL, `SmsSid` varchar(40) NOT NULL COMMENT 'where we store the cookies from twilio', `sendorder` tinyint(3) unsigned NOT NULL COMMENT 'the order we want the msg sent in', `sent` tinyint(1) NOT NULL COMMENT '0=queued, 1=sent, 2=sent-unqueued,4=rec-unread,5=recd-read', PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=143 ; I need a query that will SELECT * FROM `messages` WHERE `senddate` < $now AND `sent` = 0 (AND LIMIT TO ONLY ONE RECORD PER `patient_id`) I've tried the following: SELECT * FROM `messages` WHERE `senddate` IN (SELECT `patient_id`, max(`senddate`) GROUP by `patient_id`) AND `senddate` < $now AND `sent` = 0 ; But I get this error: MySQL client version: 5.1.37 `#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'GROUP by patient_id) AND senddate < 1270093898 AND sent = 0 LIMIT 0, 30' at line 5

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  • PHP - Get value of imput box, without a form?

    - by Dodi300
    Hello. Does anyone know how I can get the value of an imput box, without having a form? I want a sumbit button, but instead of submiting a form, I want it to change data in a MySQL database. Something like this maybe? $img1="WHAT DO I PUT HERE?" $idx=1 $sql="INSERT INTO games SET img1='$img1' WHERE id=$idx"; $result=mysql_query($sql); Could I use that code on a "onclick" event? The imput box is named "img1". Thanks for the help!

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  • Detecting when Javascript is performing poorly

    - by what-the-crap
    I'm working on a webapp in jquery that, on older machines or machines without much resources, may perform poorly. To get around this I'd like to make a degraded version that disables some of the features, particularly those that rely on large images. How can I tell if my app is running poorly on the user's computer in jquery or javascript in general? I just need a way to call a function that will degrade the app. (especially when the user may run low on system memory) The only way I can think of is for manual user intervention, but the option would add clutter for users that don't need it and users that do need it may not notice it. Thanks!

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  • SELECT DISTINCT multiple field search?

    - by Patrick
    I'm trying to search multiple fields zc_city and zc_zip for when user input and then return row results for zc_city zc_state and zc_zip $q = strtolower($_GET["q"]); if (!$q) return; $sql = "SELECT DISTINCT zc_city AS zcity FROM search_zipcodes WHERE zc_city LIKE '$q%'"; $rsd = mysql_query($sql); while($rs = mysql_fetch_array($rsd)) { $zcity = $rs['zcity']; echo "$zcity\n"; }

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  • Problem with mysql_query() ;Says resource expected .

    - by user364651
    I have this php file. The lines marked as bold are showing up the error :"mysql_query() expecets parameter 2 to be a resources. Well, the similar syntax on the line on which I have commented 'No error??' is working just fine. function checkAnswer($answerEntered,$quesId) { //This functions checks whether answer to question having ques_id = $quesId is satisfied by $answerEntered or not $sql2="SELECT keywords FROM quiz1 WHERE ques_id=$quesId"; **$result2=mysql_query($sql2,$conn);** $keywords=explode(mysql_result($result2,0)); $matches=false; foreach($keywords as $currentKeyword) { if(strcasecmp($currentKeyword,$answerEntered)==0) { $matches=true; } } return $matches; } $sql="SELECT answers FROM user_info WHERE user_id = $_SESSION[user_id]"; $result=mysql_query($sql,$conn); // No error?? $answerText=mysql_result($result,0); //Retrieve answers entered by the user $answerText=str_replace('<','',$answerText); $answerText=str_replace('>',',',$answerText); $answerText=substr($answerText,0,(strlen($answerText)-1)); $answers=explode(",",$answerText); //Get the questions that have been assigned to the user. $sql1="SELECT questions FROM user_info WHERE user_id = $_SESSION[user_id]"; **$result1=mysql_query($sql1,$conn);** $quesIdList=mysql_result($result1,0); $quesIdList=substr($quesIdList,0,(strlen($quesIdList)-1)); $quesIdArray=explode(",",$quesIdList); $reportCard=""; $i=0; foreach($quesIdArray as $currentQuesId) { $answerEnteredByUser=$answers[$i]; if(checkAnswer($answerEnteredByUser,$currentQuesId)) { $reportCard=$reportCard+"1"; } else { $reportCard=$reportCard+"0"; } $i++; } echo $reportCard; ?> Here is the file connect.php. It is working just fine for other PHP documents. <?php $conn= mysql_connect("localhost","root","password"); mysql_select_db("quiz",$conn); ?>

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  • How much faster is C++ than C#?

    - by Trap
    Or is it now the other way around? From what I've heard there are some areas in which C# proves to be faster than C++, but I've never had the guts to test it by myself. Thought any of you could explain these differences in detail or point me to the right place for information on this.

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  • Why is casting and comparing in PHP faster than is_*?

    - by tstenner
    While optimizing a function in PHP, I changed if(is_array($obj)) foreach($obj as $key=$value { [snip] } else if(is_object($obj)) foreach($obj as $key=$value { [snip] } to if($obj == (array) $obj) foreach($obj as $key=$value { [snip] } else if($obj == (obj) $obj) foreach($obj as $key=$value { [snip] } After learning about ===, I changed that to if($obj === (array) $obj) foreach($obj as $key=$value { [snip] } else if($obj === (obj) $obj) foreach($obj as $key=$value { [snip] } Changing each test from is_* to casting resulted in a major speedup (30%). I understand that === is faster than == as no coercion has to be done, but why is casting the variable so much faster than calling any of the is_*-functions?

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  • mysql select when matching multiple rows

    - by user1735943
    I have a project where I need to select only the users that answered to some questions in a certain way (based on a filter). The filter table (filter) looks like this question | answer Q1 | A Q2 | B The user table (answers) looks like this user | question | answer 1 | Q1 | A 1 | Q2 | D 2 | Q1 | A 2 | Q2 | B How can I select from the user table only the user(s) that match the filter? I tried "SELECT user FROM answers WHERE (question = Q1 AND answer = A) AND (question = Q2 AND answer = B)" and it doesn't work -- I get an empty result. Thank you.

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  • Which of these queries is more efficient?

    - by Brian
    Which of these queries are more efficient? select 1 as newAndClosed from sysibm.sysdummy1 where exists ( select 1 from items where new = 1 ) and not exists ( select 1 from status where open = 1 ) select 1 as newAndClosed from items where new = 1 and not exists ( select 1 from status where open = 1 )

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