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  • Manipulate score/rank on query results from NHibernate.Search

    - by Fernando Figueiredo
    I've been working with NHibernate, NHibernate.Search and Lucene.Net to improve the search engine used on the website I develop. Basically, I use it to search contents of corporations specification documents. This is not to be confused with Lucene's notion of documents: in my case, a specification document (which I'll hereafter call a "specdoc") can contain many pages, and the content of these pages are the ones that are actually indexed (thus, the pages themselves are the ones that fall into Lucene's concept of documents). So, the pages belong to a specdoc, that in turn belong to a corporation (so, a corporation can have many specdocs). I'm using NHibernate.Search "IndexEmbedded" and "ContainedIn" attributes to associate the pages with their specdoc and the specdocs to their corporations, so I can query for terms in specdoc pages and have Lucene/NH.Search return either the pages themselves, the specdocs, or the corporations that match the query on the pages. I can query this way and get ranked results, thus presenting results (that is, corporations, specdocs or pages) by relevance, which is great. But now I need something more. Specifically in the case where I query terms and have NH.Search return the corporations that match, I need to manually/artificially tune the score of some of the results, because there are corporations that I want to show up on the top of the result set - think of "sponsored results". I'm thinking of doing it on my application, maybe creating an entity/database table that contain an association to the corporation entity, and a score boost value. But I don't know how to feed this to Lucene and have it boost the results accordingly at search time. Initially I thought about deriving a Similarity class to do this, but it doesn't look like Similarity can be used to modify result sets at search time. As per this page, it looks like what I need is to mess around with weight or scoring. But the docs are a little superficial in that there are no examples on how to implement a custom scoring, let alone integrate it with NH.Search. So, does anyone know how to do this, or point me to some documentation or working example on how to do something similar? Thanks!

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  • Problems publishing website

    - by Oxymoron
    Recently I've began experimenting with ASP.NET MVC and the Entity Framework. Since my hostingprovider only provides me with MySQL I've been trying to set that up. Locally everything works fine, but after I publish it I get the following error: [ProviderIncompatibleException: The store provider factory type 'MySql.Data.MySqlClient.MySqlClientFactory' does not implement the IServiceProvider interface. Use a store provider that implements this interface.] Since I'm rather inexperienced with the configuring this and google is lacking a good answer I thought I'd try here. My best guess is something missing in the web.config file, but can't really make out what it is. Any help would be greatly appreciated!

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  • Linq to Entities and LEFT OUTER JOIN issue with MANY:1 relations

    - by Robert Koritnik
    Can somebody tell me, why does Linq to Entities translate many to 1 relationships to left outer join instead of inner join? Because there's referential constraint on DB itself that ensures there's a record in the right table, so inner join should be used instead (and it would work much faster) If relation was many to 0..1 left outer join would be correct. Question Is it possible to write LINQ in a way so it will translate to inner join rather than left outer join. It would speed query execution a lot... I haven't used eSQL before, but would it be wise to use it in instead of LINQ? Edit I updated my tags to include technology I'm using in the background: Entity Framework V1 Devart dotConnect for Mysql MySql database If someone could test if the same is true on Microsoft SQL server it would also give me some insight if this is Devart's issue or it's a general L2EF functionality... But I suspect EF is the culprit here.

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  • SQL Server, how to join a table in a "rotated" format (returning columns instead of rows)?

    - by Joshua Carmody
    Sorry for the lame title, my descriptive skills are poor today. In a nutshell, I have a query similar to the following: SELECT P.LAST_NAME, P.FIRST_NAME, D.DEMO_GROUP FROM PERSON P JOIN PERSON_DEMOGRAPHIC PD ON PD.PERSON_ID = P.PERSON_ID JOIN DEMOGRAPHIC D ON D.DEMOGRAPHIC_ID = PD.DEMOGRAPHIC_ID This returns output like this: LAST_NAME FIRST_NAME DEMO_GROUP --------------------------------------------- Johnson Bob Male Smith Jane Female Smith Jane Teacher Beeblebrox Zaphod Male Beeblebrox Zaphod Alien Beeblebrox Zaphid Politician I would prefer the output be similar to the following: LAST_NAME FIRST_NAME Male Female Teacher Alien Politician --------------------------------------------------------------------------------------------------------- Johnson Bob 1 0 0 0 0 Smith Jane 0 1 1 0 0 Beeblebrox Zaphod 1 0 0 1 1 The number of rows in the DEMOGRAPHIC table varies, so I can't say with certainty how many columns I need. The query needs to be flexible. Yes, it would be trivial to do this in code. But this query is one piece of a complicated set of stored procedures, views, and reporting services, many of which are outside my sphere of influence. I need to produce this output inside the database to avoid breaking the system. Any ideas? This is MS SQL Server 2005, by the way. Thanks.

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  • Active Directory - Query Group for all machines

    - by Ben Cawley
    Hi, I'm trying to obtain a list of all Machines that are members of a known group. I have the group GUID and am constructing a query using the "memberof=" format and filtering by ObjectClass. This works fine but doesn't return machines if the PrimaryGroup attribute of a machine is set to be the known group. In this case, that machine won't be returned. I've found the explanation of why this is in the following link (See Joe Kaplan's response) http://www.eggheadcafe.com/software/aspnet/29773581/active-directory-query-c.aspx Unfortunately the outlined answer is how to obtain the list of groups from a given user. I'd like to do the reverse and from a given group obtain the list of machines. It seems that the PrimaryGroup information is stored on the Machine/User side so I'm not sure if what I want to do is even possible. I had thought I would be able to query the TokenGroup attribute of the known group and then construct a query to return all machines that have the TokenGroup attribute set but it seems that not all groups have this attribute. Does anyone have any ideas or suggestions? If any clarification is needed let me know! Cheers, Ben

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  • How hard is it to modify the Django Models?

    - by alex
    I am doing geolocation, and Django does not have a PointField. So, I am forced to writing in RAW SQL. GeoDjango, the Django library, does not support the following query for MYSQL databases (can someone verify that for me?) cursor.execute("SELECT id FROM l_tag WHERE\ (GLength(LineStringFromWKB(LineString(asbinary(utm),asbinary(PointFromWKB(point(%s, %s)))))) < %s + accuracy + %s)\ I don't nkow why GeoDjango library cannot do this in MYSQL database. I hate writing RAW SQL for calculating distances between two points. Is there a way I can create my own library for Django that can handle this? If so, how hard is it?

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  • How to set SQL_BIG_SELECTS = 1 from VB(legacy ASP) with ADODB environment?

    - by conecon
    I encountered The SELECT would examine more than MAX_JOIN_SIZE rows; check your WHERE and use SET SQL_BIG_SELECTS=1 or SET SQL_MAX_JOIN_SIZE=# if the SELECT is okay error with my ASP code. ASP code has server side ADODB connection with MySQL and connection seems not be able to execute multiple query. How to implement SQL_BIG_SELECTS = 1 in my code? Set obj_db = Server.CreateObject("ADODB.Connection") Session("ConnectionString") = "dsn=dsn1016189_mysql;uid=apns;pwd=mypassword;DATABASE=mydb;APP=ASP Script;STMT=SET CHARACTER SET SJIS" obj_db.Open Session("ConnectionString") Set obj_ret = Server.CreateObject("ADODB.Recordset") obj_ret.CursorLocation = 3 and executing SQL... SQL_BIG_SELECTS = 1; SELECT pu.login_id, pu.p_login_id, pu.first_name, pu.last_name, pu.sex, pu.is_admin, pu.attendance, pu.invited, pu.reason, qaa1.answer AS qaa1_answer, COUNT(pu2.p_login_id) AS companion FROM party_user pu LEFT OUTER JOIN party_user pu2 ON pu2.p_login_id = pu.login_id LEFT OUTER JOIN qa_answer qaa1 ON qaa1.login_id = pu.login_id AND qaa1.party_id = pu.party_id AND qaa1.sort_num = '1' WHERE pu.party_id = '92' AND pu.p_login_id = '' GROUP BY pu.login_id, pu.p_login_id, pu.first_name, pu.last_name, pu.sex, pu.is_admin, pu.attendance, pu.reason, qaa1.answer, pu.invited ORDER BY pu.login_id ASC; I can't execute multiple query and above query become error. 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 'SELECT pu.login_id, pu.p_login_id, pu.first_name, pu.last_name, pu.sex, pu.is_ad' at line 1

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  • Enum in Hibernate, persisting as an enum

    - by niklassaers
    In my MySQL database, there's the column "gender enum('male','female')" I've created my enum "com.mydomain.myapp.enums.Gender", and in my Person entity I'm defined "Gender gender". Now I'd want to keep the enum type in my MySQL database, but when I launch my application I get: Wrong column type in MyApp.Person for column Gender. Found: enum, expected: integer Why is this? This would be the equivalent as if I'd annotated my "Gender gender" with "@Enumerated(EnumType.ORDINAL)", which I haven't. EnumType seems only to be able to be either ORDINAL or STRING, so how do I specify that it should treat the field as an enum, not as an int? (not that there's much difference, but enough for it to get upset about it.)

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  • Query eror handling in CodeIgniter

    - by Sajith S Narayanan
    Hi All, I am trying to execute an MySql query using the CI Active methods. If the query is malformed, then CI invokes internal server error 500 and quits without processing the next steps.. I need to roll back all the other queries processed before that error statement, and the roll back is also not happening.. can you help pls. The code snippets is as below: function dbInsertInformationToDB($data_array) { $returnID = ""; $uniqueDataArray = array(); // I prepare a array of values here $uniqueTableList = filter_unique_tables($data_array[2]); $this->db->trans_begin(); // inserting is done here // when there is a query error in $this->db->insert().. it is not rolling back the previous query executed foreach($uniqueTableList as $table_name) { $uniqueDataArray = filterDataArray($data_array,$table_name,2); $this->db->insert($table_name,$uniqueDataArray); if ($this->db->_error_message()) { $error = "I am caught!!"; } $returnID = $this->db->affected_rows(); } if ($this->db->trans_status() === FALSE) { $this->db->trans_rollback(); } else { $this->db->trans_commit(); } return "ERROR"; }

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  • Starting MySQL database server: mysqld . . . . . . . . . . . . . . failed!

    - by meder
    I restarted my VPS box ( manually/hard restart ) and ever since, mysql fails to start for whatever reason. I did a tail /var/log/syslog and I get this: Feb 20 11:49:33 kyrgyznews mysqld[11461]: ) ;InnoDB: End of page dump 575 Feb 20 11:49:33 kyrgyznews mysqld[11461]: 110220 11:49:33 InnoDB: Page checksum 1045788239, prior-to-4.0.14-form checksum 236985105 576 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: stored checksum 1178062585, prior-to-4.0.14-form stored checksum 236985105 577 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: Page lsn 0 10651, low 4 bytes of lsn at page end 10651 578 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: Page number (if stored to page already) 3, 579 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: space id (if created with >= MySQL-4.1.1 and stored already) 0 580 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: Database page corruption on disk or a failed 581 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: file read of page 3. 582 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: You may have to recover from a backup. 583 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: It is also possible that your operating 584 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: system has corrupted its own file cache 585 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: and rebooting your computer removes the 586 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: error. 587 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: If the corrupt page is an index page 588 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: you can also try to fix the corruption 589 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: by dumping, dropping, and reimporting 590 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: the corrupt table. You can use CHECK 591 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: TABLE to scan your table for corruption. 592 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: See also InnoDB: http://dev.mysql.com/doc/refman/5.0/en/forcing-recovery.html 593 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: about forcing recovery. 594 Feb 20 11:49:33 kyrgyznews mysqld[11461]: InnoDB: Ending processing because of a corrupt database page. 595 Feb 20 11:49:33 kyrgyznews mysqld_safe[11469]: ended 596 Feb 20 11:49:47 kyrgyznews /etc/init.d/mysql[12228]: 0 processes alive and '/usr/bin/mysqladmin --defaults-file=/etc/mysql/debian.cnf ping' resulted in 597 Feb 20 11:49:47 kyrgyznews /etc/init.d/mysql[12228]: ^G/usr/bin/mysqladmin: connect to server at 'localhost' failed 598 Feb 20 11:49:47 kyrgyznews /etc/init.d/mysql[12228]: error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)' 599 Feb 20 11:49:47 kyrgyznews /etc/init.d/mysql[12228]: Check that mysqld is running and that the socket: '/var/run/mysqld/mysqld.sock' exists! 600 Feb 20 11:49:47 kyrgyznews /etc/init.d/mysql[12228]: 601 Feb 20 11:49:56 kyrgyznews mysqld_safe[13437]: started 602 Feb 20 11:49:56 kyrgyznews mysqld[13440]: InnoDB: The log sequence number in ibdata files does not match 603 Feb 20 11:49:56 kyrgyznews mysqld[13440]: InnoDB: the log sequence number in the ib_logfiles! 604 Feb 20 11:49:56 kyrgyznews mysqld[13440]: 110220 11:49:56 InnoDB: Database was not shut down normally! 605 Feb 20 11:49:56 kyrgyznews mysqld[13440]: InnoDB: Starting crash recovery. 606 Feb 20 11:49:56 kyrgyznews mysqld[13440]: InnoDB: Reading tablespace information from the .ibd files... 607 Feb 20 11:49:56 kyrgyznews mysqld[13440]: InnoDB: Restoring possible half-written data pages from the doublewrite 608 Feb 20 11:49:56 kyrgyznews mysqld[13440]: InnoDB: buffer... 609 Feb 20 11:49:56 kyrgyznews mysqld[13440]: InnoDB: Database page corruption on disk or a failed 610 Feb 20 11:49:56 kyrgyznews mysqld[13440]: InnoDB: file read of page 3. 611 Feb 20 11:49:56 kyrgyznews mysqld[13440]: InnoDB: You may have to recover from a backup. I have looked at the page it referenced, http://dev.mysql.com/doc/refman/5.0/en/forcing-innodb-recovery.html, but before messing with any settings I was wondering what experienced DBAs would suggest doing? Is there any harm in forcing the recovery? PS - I did not make any updates to mysql. Version is mysql Ver 14.12 Distrib 5.0.51a, for debian-linux-gnu (i486) using readline 5.2.

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  • product suggestion based on user data

    - by Enkay
    I'm trying to add suggestions to product pages along the lines of : "Customers who purchased this item also purchased x and y". The way the data is compiled right now is a mysql table with 3 rows. PRODUCT | CUSTOMER |QUANTITY Product is the product ID. Customer is the customer ID. Quantity is the number of time that product was bought by that customer. For each product description page, the system needs to figure out which users bought that product, what other products those users bought, in what quantity and then return the 2 products that were bought the most by people who bought the current product. Hopefully this makes sense and someone can point me in the right directions as to what the mysql query should look like. Thanks.

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  • How to get SQL Function run a different query and return value from either query?

    - by RoguePlanetoid
    I need a function, but cannot seem to get it quite right, I have looked at examples here and elsewhere and cannot seem to get this just right, I need an optional item to be included in my query, I have this query (which works): SELECT TOP 100 PERCENT SKU, Description, LEN(CONVERT(VARCHAR (1000),Description)) AS LenDesc FROM tblItem WHERE Title = @Title AND Manufacturer = @Manufacturer ORDER BY LenDesc DESC This works within a Function, however the Manufacturer is Optional for this search - which is to find the description of a similar item, if none is present, the other query is: SELECT TOP 100 PERCENT SKU, Description, LEN(CONVERT(VARCHAR (1000),Description)) AS LenDesc FROM tblItem WHERE Title = @Title ORDER BY LenDesc DESC Which is missing the Manufacturer, how to I get my function to use either query based on the Manufacturer Value being present or not. The reason is I will have a function which first checks an SKU for a Description, if it is not present - it uses this method to get a Description from a Similar Product, then updates the product being added with the similar product's description. Here is the function so far: ALTER FUNCTION [dbo].[GetDescriptionByTitleManufacturer] ( @Title varchar(400), @Manufacturer varchar(160) ) RETURNS TABLE AS RETURN ( SELECT TOP 100 PERCENT SKU, Description, LEN(CONVERT(VARCHAR (1000),Description)) AS LenDesc FROM tblItem WHERE Title = @Title AND Manufacturer = @Manufacturer ORDER BY LenDesc DESC ) I've tried adding BEGINs and IF...ELSEs but get errors or syntax problems each way I try it, I want to be able to do something like this pseudo-function (which does not work): ALTER FUNCTION [dbo].[GetDescriptionByTitleManufacturer] ( @Title varchar(400), @Manufacturer varchar(160) ) RETURNS TABLE AS BEGIN IF (@Manufacturer = Null) RETURN ( SELECT TOP 100 PERCENT SKU, Description, LEN(CONVERT(VARCHAR (1000),Description)) AS LenDesc FROM tblItem WHERE Title = @Title ORDER BY LenDesc DESC ) ELSE RETURN ( SELECT TOP 100 PERCENT SKU, Description, LEN(CONVERT(VARCHAR (1000),Description)) AS LenDesc FROM tblItem WHERE Title = @Title AND Manufacturer = @Manufacturer ORDER BY LenDesc DESC ) END

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  • How do you handle descriptive database table names and their effect on foreign key names?

    - by Carvell Fenton
    Hello, I am working on a database schema, and am trying to make some decisions about table names. I like at least somewhat descriptive names, but then when I use suggested foreign key naming conventions, the result seems to get ridiculous. Consider this example: Suppose I have table session_subject_mark_item_info And it has a foreign key that references sessionSubjectID in the session_subjects table. Now when I create the foreign key name based on fk_[referencing_table]__[referenced_table]_[field_name] I end up with this maddness: fk_session_subject_mark_item_info__session_subjects_sessionSubjectID Would this type of a foreign key name cause me problems down the road, or is it quite common to see this? Also, how do the more experienced database designers out there handle the conflict between descriptive naming for readability vs. the long names that result? I am using MySQL and MySQL Workbench if that makes any difference. Thanks!

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  • php echo doesnt print newlines

    - by Skun
    Hey ! I started doing a new project in PHP / MySql . The Aim of this project is to manage articles for a magazine that i am the editor of. So the content of the articles, i decided i would store with the "TEXT" column type of MySql Now when i retrieve this column and print it with echo, the newlines are not there. Its all on the same line. $resset = mysql_query("select txt from articles where id = 1"); $row = mysql_fetch_assoc($resset); $txt = $row['txt']; echo $txt; //doesnt print it as it is in the database as it was typed (multiline) Find below, the text as it looks in the database and as it looks when it is echoed But within the database, its stored with newlines. Has anybody else encountered this problem? Please help me as my project depends on this :|

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  • Do MyISAM holes get filled in automatically?

    - by NNN
    When you run a delete on a MyISAM table, it leaves a hole in the table until the table is optimized. This affects concurrent inserts. On the default setting, concurrent_inserts only work for tables without holes. However, in the documentation for MyISAM, under the concurrent_insert section it says: Enables concurrent inserts for all MyISAM tables, even those that have holes. For a table with a hole, new rows are inserted at the end of the table if it is in use by another thread. Otherwise, MySQL acquires a normal write lock and inserts the row into the hole. http://dev.mysql.com/doc/refman/5.0/en/server-system-variables.html#sysvar_concurrent_insert Does that mean MyISAM automatically fills in holes whenever a new row is insert into the table? Previously I thought the holes would not be fixed until you OPTIMIZE a table.

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  • How can I work around SQL Server - Inline Table Value Function execution plan variation based on par

    - by Ovidiu Pacurar
    Here is the situation: I have a table value function with a datetime parameter ,lest's say tdf(p_date) , that filters about two million rows selecting those with column date smaller than p_date and computes some aggregate values on other columns. It works great but if p_date is a custom scalar value function (returning the end of day in my case) the execution plan is altered an the query goes from 1 sec to 1 minute execution time. A proof of concept table - 1K products, 2M rows: CREATE TABLE [dbo].[POC]( [Date] [datetime] NOT NULL, [idProduct] [int] NOT NULL, [Quantity] [int] NOT NULL ) ON [PRIMARY] The inline table value function: CREATE FUNCTION tdf (@p_date datetime) RETURNS TABLE AS RETURN ( SELECT idProduct, SUM(Quantity) AS TotalQuantity, max(Date) as LastDate FROM POC WHERE (Date < @p_date) GROUP BY idProduct ) The scalar value function: CREATE FUNCTION [dbo].[EndOfDay] (@date datetime) RETURNS datetime AS BEGIN DECLARE @res datetime SET @res=dateadd(second, -1, dateadd(day, 1, dateadd(ms, -datepart(ms, @date), dateadd(ss, -datepart(ss, @date), dateadd(mi,- datepart(mi,@date), dateadd(hh, -datepart(hh, @date), @date)))))) RETURN @res END Query 1 - Working great SELECT * FROM [dbo].[tdf] (getdate()) The end of execution plan: Stream Aggregate Cost 13% <--- Clustered Index Scan Cost 86% Query 2 - Not so great SELECT * FROM [dbo].[tdf] (dbo.EndOfDay(getdate())) The end of execution plan: Stream Aggregate Cost 4% <--- Filter Cost 12% <--- Clustered Index Scan Cost 86%

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  • PHP: using REGEX to get the tablename from a mysql query

    - by Matt
    Hi Guys, Consider these three mysql statements: select * from Users; select id, title, value from Blogs; select id, feelURL, feelTitle from Feeds where id = 1; Now im not very good at REGEX, but i want to get the table name from the mysql query. Could someone possibly create one for me with a little explanation. Thanks,

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  • ZIP Numerous Blob Files

    - by Michael
    I have a database table that contains numerous PDF blob files. I am attempting to combine all of the files into a single ZIP file that I can download and then print. Please help! <?php include 'config.php'; include 'connect.php'; $session= $_GET[session]; $query = " SELECT $tbl_uploads.username, $tbl_uploads.description, $tbl_uploads.type, $tbl_uploads.size, $tbl_uploads.content, $tbl_members.session FROM $tbl_uploads LEFT JOIN $tbl_members ON $tbl_uploads.username = $tbl_members.username WHERE $tbl_members.session= '$session'"; $result = mysql_query($query) or die('Error, query failed'); while(list($username, $description, $type, $size, $content) = mysql_fetch_array($result)) { header("Content-length: $size"); header("Content-type: $type"); header("Content-Disposition: inline; filename=$username-$description.pdf"); echo $content; } $files = array('File 1 from database', 'File 2 from database'); $zip = new ZipArchive; $zip->open('file.zip', ZipArchive::CREATE); foreach ($files as $file) { $zip->addFile($file); } $zip->close(); header('Content-Type: application/zip'); header('Content-disposition: attachment; filename=filename.zip'); header('Content-Length: ' . filesize($zipfilename)); readfile($zipname); mysql_close($link); exit; ?>

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  • Cassandra or MySQL/PostgreSQL?

    - by Ivri
    Hi! I have huge database (kinda wordnet). And want to know if it's easier to use Cassandra instead of MySQL|PostrgreSQL All my life I was using MySQL and PostrgreSQL and I could easily think in terms of relational algebra, but several weeks ago I learned about cassandra and that it's used in facebook and twitter. Is it more convenient? What DBMS are usually used nowadays to store social net's data, relationships between objects, wordnet?

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  • Checking inherited attributes in an 'ancestry' based SQL table

    - by Brendon Muir
    I'm using the ancestry gem to help organise my app's tree structure in the database. It basically writes a childs ancestor information to a special column called 'ancestry'. The ancestry column for a particular child might look like '1/34/87' where the parent of this child is 87, and then 87's parent is 34 and 34's is 1. It seems possible that we could select rows from this table each with a subquery that checks all the ancestors to see if a certain attribute it set. E.g. in my app you can hide an item and its children just by setting the parent element's visibility column to 0. I want to be able to find all the items where none of their ancestors are hidden. I tried converting the slashes to comma's with the REPLACE command but IN required a set of comma separated integers rather than one string with comma separated string numbers. It's funny, because I can do this query in two steps, e.g. retrieve the row, then take its ancestry column, split out the id's and make another query that checks that the id is IN that set of id's and that visibility isn't ever 0 and whala! But joining these into one query seems to be quite a task. Much searching has shown a few answers but none really do what I want. SELECT * FROM t1 WHERE id = 99; 99's ancestry column reads '1/34/87' SELECT * FROM t1 WHERE visibility = 0 AND id IN (1,34,87); kind of backwards, but if this returns no rows then the item is visible. Has anyone come across this before and come up with a solution. I don't really want to go the stored procedure route. It's for a rails app.

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  • PHP Post Count in Forum

    - by Chris
    I'm currently desiging a forum application, I considered using a premade but decided against it as it's useful for me to learn some of the techniques. So I've written a fairly full featured forum... great. One of the problems I want to solve is to include user data for each post, at the minute the post table includes the poster ID (obviously) and I added the poster's username at a later date so I didn't have to query the User DB for X number of posts in a thread. However, it's become apparent I now want to do this, usernames don't need to update retrospectively, however avatars, sigs, and especially post counts need to update actively, so data in some form needs keeping up to date somewhere... What would be a good way of implementing this? I obviously don't want to include any more user data on the Posts DB table than necessary, but I'm struggling to find an easy way to do this short of querying the DB for each post in a thread, which is potentially going to create a lot of traffic. How have other people solved this, I've been examining the code on some other open source apps but I can't find what I'm looking for. Is it possible to select multiple records in one query? In which case I could build an array dynamically on each page request (eg 'SQL blah blah' then a for each loop to insert the ID's). Could I join the tables each time? Do I submit a query for each post? Hmm.

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