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  • How to reference other documents in a couchDB view (joining like functionality)

    - by Surfrdan
    We have a CouchDB representation of an XML database which we use to power a javascript based frontend for manipulating the XML documents. The basic structure is a simple 3 level hierachy. i.e. A - B - C A: Parent doucument (type A) B: any number of child documents of parent type A C: any number of child documents of parent type B We represent these 3 document types in CouchDB with a 'type' attribute: e.g. { "_id":"llgc-id:433", "_rev":"1-3760f3e01d7752a7508b047e0d094301", "type":"A", "label":"Top Level A document", "logicalMap":{ "issues":{ "1":{ "URL":"http://hdl.handle.net/10107/434-0", "FILE":"llgc-id:434" }, "2":{ "URL":"http://hdl.handle.net/10107/467-0", "FILE":"llgc-id:467" etc... } } } } { "_id":"llgc-id:433", "_rev":"1-3760f3e01d7752a7508b047e0d094301", "type":"B", "label":"a B document", } What I want to do is produce a view which returns documents just like the A type but includes the label attribute from the B document within the logicalMap list e.g. { "_id":"llgc-id:433", "_rev":"1-3760f3e01d7752a7508b047e0d094301", "type":"A", "label":"Top Level A document", "logicalMap":{ "issues":{ "1":{ "URL":"http://hdl.handle.net/10107/434-0", "FILE":"llgc-id:434", "LABEL":"a B document" }, "2":{ "URL":"http://hdl.handle.net/10107/467-0", "FILE":"llgc-id:467", "LABEL":"another B document" etc... } } } } I'm struggling to get my head around the best way to perform this. It looks like it should be fairly simple though!

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  • Efficient algorithm to distribute work?

    - by Zwei Steinen
    It's a bit complicated to explain but here we go. We have problems like this (code is pseudo-code, and is only for illustrating the problem. Sorry it's in java. If you don't understand, I'd be glad to explain.). class Problem { final Set<Integer> allSectionIds = { 1,2,4,6,7,8,10 }; final Data data = //Some data } And a subproblem is: class SubProblem { final Set<Integer> targetedSectionIds; final Data data; SubProblem(Set<Integer> targetedSectionsIds, Data data){ this.targetedSectionIds = targetedSectionIds; this.data = data; } } Work will look like this, then. class Work implements Runnable { final Set<Section> subSections; final Data data; final Result result; Work(Set<Section> subSections, Data data) { this.sections = SubSections; this.data = data; } @Override public void run(){ for(Section section : subSections){ result.addUp(compute(data, section)); } } } Now we have instances of 'Worker', that have their own state sections I have. class Worker implements ExecutorService { final Map<Integer,Section> sectionsIHave; { sectionsIHave = {1:section1, 5:section5, 8:section8 }; } final ExecutorService executor = //some executor. @Override public void execute(SubProblem problem){ Set<Section> sectionsNeeded = fetchSections(problem.targetedSectionIds); super.execute(new Work(sectionsNeeded, problem.data); } } phew. So, we have a lot of Problems and Workers are constantly asking for more SubProblems. My task is to break up Problems into SubProblem and give it to them. The difficulty is however, that I have to later collect all the results for the SubProblems and merge (reduce) them into a Result for the whole Problem. This is however, costly, so I want to give the workers "chunks" that are as big as possible (has as many targetedSections as possible). It doesn't have to be perfect (mathematically as efficient as possible or something). I mean, I guess that it is impossible to have a perfect solution, because you can't predict how long each computation will take, etc.. But is there a good heuristic solution for this? Or maybe some resources I can read up before I go into designing? Any advice is highly appreciated!

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  • MySQL query puzzle - finding what WOULD have been the most recent date

    - by Hank
    I've looked all over and haven't yet found an intelligent way to handle this, though I feel sure one is possible: One table of historical data has quarterly information: CREATE TABLE Quarterly ( unique_ID INT UNSIGNED NOT NULL, date_posted DATE NOT NULL, datasource TINYINT UNSIGNED NOT NULL, data FLOAT NOT NULL, PRIMARY KEY (unique_ID)); Another table of historical data (which is very large) contains daily information: CREATE TABLE Daily ( unique_ID INT UNSIGNED NOT NULL, date_posted DATE NOT NULL, datasource TINYINT UNSIGNED NOT NULL, data FLOAT NOT NULL, qtr_ID INT UNSIGNED, PRIMARY KEY (unique_ID)); The qtr_ID field is not part of the feed of daily data that populated the database - instead, I need to retroactively populate the qtr_ID field in the Daily table with the Quarterly.unique_ID row ID, using what would have been the most recent quarterly data on that Daily.date_posted for that data source. For example, if the quarterly data is 101 2009-03-31 1 4.5 102 2009-06-30 1 4.4 103 2009-03-31 2 7.6 104 2009-06-30 2 7.7 105 2009-09-30 1 4.7 and the daily data is 1001 2009-07-14 1 3.5 ?? 1002 2009-07-15 1 3.4 && 1003 2009-07-14 2 2.3 ^^ then we would want the ?? qtr_ID field to be assigned '102' as the most recent quarter for that data source on that date, and && would also be '102', and ^^ would be '104'. The challenges include that both tables (particularly the daily table) are actually very large, they can't be normalized to get rid of the repetitive dates or otherwise optimized, and for certain daily entries there is no preceding quarterly entry. I have tried a variety of joins, using datediff (where the challenge is finding the minimum value of datediff greater than zero), and other attempts but nothing is working for me - usually my syntax is breaking somewhere. Any ideas welcome - I'll execute any basic ideas or concepts and report back.

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  • How can I use SQL to select duplicate records, along with counts of related items?

    - by mipadi
    I know the title of this question is a bit confusing, so bear with me. :) I have a (MySQL) database with a Person record. A Person also has a slug field. Unfortunately, slug fields are not unique. There are a number of duplicate records, i.e., the records have different IDs but the same first name, last name, and slug. A Person may also have 0 or more associated articles, blog entries, and podcast episodes. If that's confusing, here's a diagram of the structure: I would like to produce a list of records that match this criteria: duplicate records (i.e., same slug field) for people who also have at least 1 article, blog entry, or podcast episode. I have a SQL query that will list all records with the same slug fields: SELECT id, first_name, last_name, slug, COUNT(slug) AS person_records FROM people_person GROUP BY slug HAVING (COUNT(slug) > 1) ORDER BY last_name, first_name, id; But this includes records for people that may not have at least 1 article, blog entry, or podcast. Can I tweak this to fit the second criteria?

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  • Oracle (Old?) Joins - A tool/script for conversion?

    - by Grasper
    I have been porting oracle selects, and I have been running across a lot of queries like so: SELECT e.last_name, d.department_name FROM employees e, departments d WHERE e.department_id(+) = d.department_id; ...and: SELECT last_name, d.department_id FROM employees e, departments d WHERE e.department_id = d.department_id(+); Are there any guides/tutorials for converting all of the variants of the (+) syntax? What is that syntax even called (so I can scour google)? Even better.. Is there a tool/script that will do this conversion for me (Preferred Free)? An optimizer of some sort? I have around 500 of these queries to port.. When was this standard phased out? Any info is appreciated.

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  • how to Solve the "Digg" problem in MongoDB

    - by user193116
    A while back,a Digg developer had posted this blog ,"http://about.digg.com/blog/looking-future-cassandra", where the he described one of the issues that were not optimally solved in MySQL. This was cited as one of the reasons for their move to Cassandra. I have been playing with MongoDB and I would like to understand how to implement the MongoDB collections for this problem From the article, the schema for this information in MySQL : CREATE TABLE Diggs ( id INT(11), itemid INT(11), userid INT(11), digdate DATETIME, PRIMARY KEY (id), KEY user (userid), KEY item (itemid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; CREATE TABLE Friends ( id INT(10) AUTO_INCREMENT, userid INT(10), username VARCHAR(15), friendid INT(10), friendname VARCHAR(15), mutual TINYINT(1), date_created DATETIME, PRIMARY KEY (id), UNIQUE KEY Friend_unique (userid,friendid), KEY Friend_friend (friendid) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; This problem is ubiquitous in social networking scenario implementation. People befriend a lot of people and they in turn digg a lot of things. Quickly showing a user what his/her friends are up to is very critical. I understand that several blogs have since then provided a pure RDBMs solution with indexes for this issue; however I am curious as to how this could be solved in MongoDB.

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  • Using a join with three tables when a field might be null

    - by John
    Hello, The code below works great. It combines data from two MySQL tables. I would like to modify it by pulling in some data from a third MySQL table called "comment." In the HTML table below, "title" is a field in the MySQL table "submission." Every "title" has a corresponding "submissionid" field. The field "submissionid" is also found in the "comment" MySQL table. In the HTML table below, I would like "countComments" to equal the number of times a field called "commentid" appears in the MySQL table "comment" for any given "submissionid," where the "submissionid" is the same in both the "submission" and "comment" tables, and where the "submissionid" corresponds to the "title" being used. Here's the catch: if there is no row in the MySQL table "comment" that corresponds with the "submissionid" being used for "table", I would like "countComments" to equal to zero. How can I do this? Thanks in advance, John $sqlStr = "SELECT s.loginid, s.title, s.url, s.displayurl, l.username FROM submission AS s, login AS l WHERE s.loginid = l.loginid ORDER BY s.datesubmitted DESC LIMIT 10"; $result = mysql_query($sqlStr); $arr = array(); echo "<table class=\"samplesrec\">"; while ($row = mysql_fetch_array($result)) { echo '<tr>'; echo '<td class="sitename1"><a href="http://www.'.$row["url"].'">'.$row["title"].'</a></td>'; echo '</tr>'; echo '<tr>'; echo '<td class="sitename2"><a href="http://www...com/sandbox/members/index.php?profile='.$row["username"].'">'.$row["username"].'</a><a href="http://www...com/sandbox/comments/index.php?submission='.$row["title"].'">'.$row["countComments"].'</a></td>'; echo '</tr>'; } echo "</table>";

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  • Bulk update + SQL + self join

    - by Nev_Rahd
    Hello All I would like to update a column in Table with reference to other column(s) in same table. Ex: As in figure below - I would like to update effective endate with min date whichever is greater than effective Start Date of currrent record. How can this be acheived in T-SQL. Can this be done with single update statement ? Thanks.

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  • update query with join on two tables

    - by dba_query
    I have customer and address tables. query: select * from addresses a, customers b where a.id = b.id returns 474 records For these records, I'd like to add the id of customer table into cid of address table. Example: If for the first record the id of customer is 9 and id of address is also 9 then i'd like to insert 9 into cid column of address table. I tried: update addresses a, customers b set a.cid = b.id where a.id = b.id but this does not seem to work.

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  • Fetch Max from a date column grouped by a particular field

    - by vamyip
    Hi, I have a table similar to this: LogId RefId Entered ================================== 1 1 2010-12-01 2 1 2010-12-04 3 2 2010-12-01 4 2 2010-12-06 5 3 2010-12-01 6 1 2010-12-10 7 3 2010-12-05 8 4 2010-12-01 Here, LogId is unique; For each RefId, there are multiple entries with timestamp. What I want to extract is LogId for each latest RefId. I tried solutions from this link:http://stackoverflow.com/questions/121387/sql-fetch-the-row-which-has-the-max-value-for-a-column. But, it returns multiple rows with same RefId. Can someone help me with this? Thanks Vamyip

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  • Problems writing a query to join two tables

    - by Psyche
    Hello, I'm working on a script which purpose is to grant site users access to different sections of the site menu. For this I have created two tables, "menu" and "rights": menu - id - section_name rights - id - menu_id (references column id from menu table) - user_id (references column id from users table) How can a query be written in order to get all menu sections and mark the ones where a given user has access. I'm using PHP and Postgres. Thank you.

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  • Linq2Sql How to write outer join query?

    - by Malcolm
    Hi, I have following SQL tables. ImportantMessages impID Message ImportantMessageUsers imuID imuUserID imuImpID I want to write a Linq2Sql query so that it returns any rows from ImportantMessages that does not have a record in ImportantMessagesUsers. Matchiing fields are impID ----- imuImpID Assume imuUserID of 6

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  • How to do a join with ttwo tables ??

    - by bahamut100
    HI, I try to translate this query : SELECT * FROM `reunion` , lieu WHERE reunion.lieu_reunion = lieu.id_lieu to propel query : $c=new Criteria(); $c->addJoin(ReunionPeer::LIEU_REUNION,LieuPeer::ID_LIEU, Criteria::LEFT_JOIN); $this->reunions = ReunionPeer::doSelect($c); But in my template, when I made a print_r($reunions), the field "ville" (from the table 'lieu') is not present. Why ??

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  • Oracle (Old?) Joins - A tool for conversion?

    - by Grasper
    I have been porting oracle selects, and I have been running across a lot of queries like so: SELECT e.last_name, d.department_name FROM employees e, departments d WHERE e.department_id(+) = d.department_id; ...and: SELECT last_name, d.department_id FROM employees e, departments d WHERE e.department_id = d.department_id(+); Are there any guides/tutorials for converting all of the variants of the (+) syntax? What is that syntax even called (so I can scour google)? Even better.. Is there a tool that will do this conversion for me? When was this standard phased out? Any info is appreciated.

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  • Join unrelated tables through a second level connected table

    - by Andy M
    Hello! I have two tables of activities on a page: Views & Comments. Views id timestamp project_id user_id page_id Comments id timestamp project_id user_id page_id comment Pages id project_id title Now pages are related to projects: Projects id account_id title I am trying to create a summary page that combines views and comments ordered by time (so that the most recent views/comments are at the beginning, grouped by projects. Also, only projects for a specific account. So the result could potentially be: Project 1 View 5 (June 20th) View 4 (June 18th) Comment 5 (June 15th) Comment 4 (June 14th) Comment 3 (June 12th) Project 3 View 3 (June 10th) View 2 (June 8th) Comment 2 (June 7th) Project 2 View 1 (June 5th) Comment 1 (June 4th) If you could help with how to do this using SQL (or even doctrine) that would be awesome. Thank you.

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  • How to join table to itself and select max values in SQL

    - by Jakub Konop
    I have a contracts table: contractId date price partId 1 20120121 10 1 2 20110130 9 1 3 20130101 15 2 4 20110101 20 2 The contract with greatest date being the active contract (don't blame me, I blame infor for creating xpps) I need to create query to see only active contracts (one contract per part, the contract with highest date). So the result of the query should be like this: contractId date price partId 1 20120121 10 1 3 20130101 15 2 I am out of ideas here, I tried self joining the table, I tried aggregation functions, but I can't figure it out. If anyone would have any idea, please share them with me..

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  • JOIN in SQL with one-to-many relationship

    - by Kristopher Ives
    I'm making a tool to track calls to house/senate reps, and I have 2 tables of importance here: reps rep_id rep_name # and more info comments rep_id status # enum about result of contact comment I want to query for all reps joining the most recent associated comments and in some cases joining comments of a specific status, but there might not be any comments associated with that rep yet. THANKS!

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  • SQL Query over three different tables

    - by choise
    i got three tables CATS id name ------------------------------ 1 category1 2 category2 3 category3 4 category4 PRODUCT id name ------------------------------ 1 product1 2 product2 ZW-CAT-PRODUCT id_cats id_product ------------------------------ 1 1 3 1 4 2 now i want to get my products and their categories product1 => category1,category3 product2 => category4 is there a way to get this array (or object or something) with one mysql query? i tried a bit with JOINS, but it seems thats this is not exactly what i need, or? currently i'm using 3 querys (i think thats too much). any suggestions?

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  • mysql - combining columns and tables

    - by Phil Jackson
    Hi, I'm not much of a SQL man so I'm seeking help for this one. I have a site where I have a database for all accounts and whatnot, and another for storing actions that the user has done on the site. Each user has their own table but I want to combine the data of each user group ( all users that are "linked together" ) and order that data in the time the actions took place. Heres what I have; <?php $query = "SELECT `TALKING_TO` FROM `nnn_instant_messaging` WHERE `AUTHOR` = '" . DISPLAY_NAME . "' AND `TALKING_TO` != ''"; $query = mysql_query( $query, $CON ) or die( "_error_ " . mysql_error()); if( mysql_num_rows( $query ) != 0 ) { $table_str = ""; $select_ref_clause = "( "; $select_time_stamp_clause = "( "; while( $row = mysql_fetch_array( $query ) ) { $table_str .= "`actvbiz_networks`.`" . $row['TALKING_TO'] . "`, "; $select_ref_clause .= "`actvbiz_networks`.`" . $row['TALKING_TO'] . ".REF`, "; $select_time_stamp_clause .= "`actvbiz_networks`.`" . $row['TALKING_TO'] . ".TIME_STAMP`, "; } $table_str = $table_str . "`actvbiz_networks`.`" . DISPLAY_NAME . "`"; $select_ref_clause = substr($select_ref_clause, 0, -2) . ") AS `REF`, "; $select_time_stamp_clause = substr($select_time_stamp_clause, 0, -2) . " ) AS `TIME_STAMP`"; }else{ $table_str = "`actvbiz_networks`.`" . DISPLAY_NAME . "`"; $select_ref_clause = "`REF`, "; $select_time_stamp_clause = "`TIME_STAMP`"; } $where_clause = $select_ref_clause . $select_time_stamp_clause; $query = "SELECT " . $where_clause . " FROM " . $table_str . " ORDER BY TIME_STAMP"; die($query); $query = mysql_query( $query, $CON ) or die( "_error_ " . mysql_error()); if( mysql_num_rows( $query ) != 0 ) { }else{ ?> <p>Currently no actions have taken place in your network.</p> <?php } ?> The code above returns the sql statement: SELECT ( `actvbiz_networks`.`john_doe.REF`, `actvbiz_networks`.`Emmalene_Jackson.REF`) AS `REF`, ( `actvbiz_networks`.`john_doe.TIME_STAMP`, `actvbiz_networks`.`Emmalene_Jackson.TIME_STAMP` ) AS `TIME_STAMP` FROM `actvbiz_networks`.`john_doe`, `actvbiz_networks`.`Emmalene_Jackson`, `actvbiz_networks`.`act_web_designs` ORDER BY TIME_STAMP I really am learning on my feet with SQL. Its not the PHP I have a problem with ( I can quite happly code away with PHP ) I'ts just help with the SQL statement. Any help much appreciated, REgards, Phil

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  • self join to select consecutive numbers

    - by shantanuo
    CREATE TABLE `mybug` ( `SEAT_NO` decimal(2,0) NOT NULL, `ROW_NO` decimal(2,0) NOT NULL, `COL_NO` decimal(2,0) NOT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1; INSERT INTO `mybug` VALUES ('1','1','1'),('26','7','2'),('31','8','2'),('32','8','1'),('33','9','1'),('34','9','2'),('35','9','5'),('36','9','6'),('37','10','6'),('38','10','5'),('39','10','2'),('40','10','1'),('41','11','1'),('42','11','2'),('43','11','4'),('44','11','5'); +---------+--------+--------+ | SEAT_NO | ROW_NO | COL_NO | +---------+--------+--------+ | 1 | 1 | 1 | | 26 | 7 | 2 | | 31 | 8 | 2 | | 32 | 8 | 1 | | 33 | 9 | 1 | | 34 | 9 | 2 | | 35 | 9 | 5 | | 36 | 9 | 6 | | 37 | 10 | 6 | | 38 | 10 | 5 | | 39 | 10 | 2 | | 40 | 10 | 1 | | 41 | 11 | 1 | | 42 | 11 | 2 | | 43 | 11 | 4 | | 44 | 11 | 5 | +---------+--------+--------+ 16 rows in set (0.00 sec) In the above chart, I need to select 2 seats those are in the same row AND column numbers are next to each other. For e.g. Seat Numbers 38 & 39 can not be issued even if both the seats are from the same row because the column numbers 2 & 5 are not adjacent. The expected results are as follows: 31 33 35 37 39 41 43 These are the starting numbers and the next seat will be automatically booked as well. for e.g. 31 & 32

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  • Best way to map/join two autogenerated enums

    - by tomlip
    What is the best C++ (not C++11) way of joining two enums from autogenerated class similar to one presented below: namespace A { namespace B { ... class CarInfo { enum State { // basically same enums defined in different classes Running, Stopped, Broken } } class BikeInfo { enum State { // basically same enums defined in different classes Running, Stopped, Broken } } } } What is needed is unified enum State for both classes that is seen to outside world alongside with safe type conversion. The best and probably most straightforward way I came up with is to create external enum: enum State { Running, Stopped, Broken } together with conversion functions State stateEnumConv(A::B::CarInfo::State aState); State stateEnumConv(A::B::BikeInfo::State aState); A::B::CarInfo::State stateEnumConv(State aState); A::B::BikeInfo::State stateEnumConv(State aState); Direction into right approach is needed. Gosh coming from C I hate those long namespaces everywhere an I wish it could be only A::B level like in presented example. Four conversion functions seem redundant note that CarInfo::State and BikeInfo::State has same enum "members".

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  • SQL - get the article title with the last comment date

    - by stacker
    I have articles table, article_comments. I want to get the value: last_modified_all of article. I need this value to be the great date of this two: the last_modified field of articles table. the last comment of article_comments last_modified column. Can someone help me? the structure is very simple, and you can guess is without problem.

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  • Joining two tables (through a link), one which may yield multiple rows, together into one result.

    - by Eikern
    Lets say I've got a table listing car brands or models: Cars: Id | Brand ----------- 1 | BMW 2 | Audi 3 | Volvo And I've also got another table which links features. Link: Id | carid | featureid ----------------------- 1 | 1 | 1 2 | 1 | 2 3 | 2 | 2 4 | 3 | 1 5 | 3 | 2 6 | 3 | 3 And I've got the table listing the features. Features: Id | Feature ----------- 1 | A/C 2 | 4WD 3 | Heated seats I want to list these results on my front page like this: BMW A/C 4WD Audi 4WD Volvo A/C 4WD Heated seats What's the best/most efficient way of doing this (using PHP and MySQL)?

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