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  • How to use database to generate multiple folder content page?

    - by VenomVipes
    Scenario :I am trying to build a Mobile Entertainment Portal. It will enable users to download Music & Movies to their Cell Phones... Problem Exp : Suppose I upload 100 folders of Songs, each folder is for one Album. I want a way to generate a page with all the folders name (Album Name) in it. If user click on the page, they should be taken to a page where they get list of all songs in the album. Clicking on any song name will let them download it. Can it be done anyway or will I have to manually design each of the 3 pages for each album. If I do that, its time consuming and also will be difficult to change anything like footer, header...

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  • Does introducing foreign keys to MySQL reduce performance

    - by Tam
    I'm building Ruby on Rails 2.3.5 app. By default, Ruby on Rails doesn't provide foreign key contraints so I have to do it manually. I was wondering if introducing foreign keys reduces query performance on the database side enough to make it not worth doing. Performance in this case is my first priority as I can check for data consistency with code. What is your recommendation in general? do you recommend using foreign keys? and how do you suggest I should measure this?

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  • c# finding matching words in table column using Linq2Sql

    - by David Liddle
    I am trying to use Linq2Sql to return all rows that contain values from a list of strings. The linq2sql class object has a string property that contains words separated by spaces. public class MyObject { public string MyProperty { get; set; } } Example MyProperty values are: MyObject1.MyProperty = "text1 text2 text3 text4" MyObject2.MyProperty = "text2" For example, using a string collection, I pass the below list var list = new List<>() { "text2", "text4" } This would return both items in my example above as they both contain "text2" value. I attempted the following using the below code however, because of my extension method the Linq2Sql cannot be evaluated. public static IQueryable<MyObject> WithProperty(this IQueryable<MyProperty> qry, IList<string> p) { return from t in qry where t.MyProperty.Contains(p, ' ') select t; } I also wrote an extension method public static bool Contains(this string str, IList<string> list, char seperator) { if (String.IsNullOrEmpty(str) || list == null) return false; var splitStr = str.Split(new char[] { seperator }, StringSplitOptions.RemoveEmptyEntries); foreach (string s in splitStr) foreach (string l in list) if (String.Compare(s, l, true) == 0) return true; return false; } Any help or ideas on how I could achieve this?

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  • PostgreSQL: How to index all foreign keys?

    - by biggusjimmus
    I am working with a large PostgreSQL database, and I are trying to tune it to get more performance. Our queries and updates seem to be doing a lot of lookups using foreign keys. What I would like is a relatively simple way to add Indexes to all of our foreign keys without having to go through every table (~140) and doing it manually. In researching this, I've come to find that there is no way to have Postgres do this for you automatically (like MySQL does), but I would be happy to hear otherwise there, too.

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  • Custom configuration file custom_config.js not working?

    - by nanoquetz9l
    Hello gals/guys, I am trying to use a custom configuration file instead of the default config.js file in the ckeditor root. I have placed a renamed copy of the config.js file in my webroot and call it with customConfig. It is not working for me though. Is my syntax creating any issues? I used the dev docs site as a ref: http://docs.cksource.com/CKEditor_3.x/D ... igurations Any ides or comments will really help me out. Im stuck. Thanks!! nano <p></p> CKEDITOR.replace( 'ticket_text' ); CKEDITOR.replace( 'ticket_text1', { customConfig : '/ckeditor/custom_config.js' });

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  • Stored procedure with output parameters vs. table-valued function?

    - by abatishchev
    Which approach is better to use if I need a member (sp or func) returning 2 parameters: CREATE PROCEDURE Test @in INT, @outID INT OUT, @amount DECIMAL OUT AS BEGIN ... END or CREATE FUNCTION Test ( @in INT ) RETURNS @ret TABLE (outID INT, amount DECIMAL) AS BEGIN ... END What are pros and cons of each approach considering that the result will passed to another stored procedure: EXEC Foobar @outID, @outAmount

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  • PHP - SQL query to get update time from table status

    - by Tribalcomm
    This is my php code (I already have a connection to the db): $array = mysql_query("SHOW TABLE STATUS FROM mytable;"); while ($array = mysql_fetch_array($result)) { $updatetime = $array['Update_time']; } echo $updatetime; I get: Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource. I am running MySQL 5.0.89 and PHP5. I do not want to add a new field to the table... I want to use the table status... Any help? Thanks!

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  • Can MySQL reasonably perform queries on billions of rows?

    - by haxney
    I am planning on storing scans from a mass spectrometer in a MySQL database and would like to know whether storing and analyzing this amount of data is remotely feasible. I know performance varies wildly depending on the environment, but I'm looking for the rough order of magnitude: will queries take 5 days or 5 milliseconds? Input format Each input file contains a single run of the spectrometer; each run is comprised of a set of scans, and each scan has an ordered array of datapoints. There is a bit of metadata, but the majority of the file is comprised of arrays 32- or 64-bit ints or floats. Host system |----------------+-------------------------------| | OS | Windows 2008 64-bit | | MySQL version | 5.5.24 (x86_64) | | CPU | 2x Xeon E5420 (8 cores total) | | RAM | 8GB | | SSD filesystem | 500 GiB | | HDD RAID | 12 TiB | |----------------+-------------------------------| There are some other services running on the server using negligible processor time. File statistics |------------------+--------------| | number of files | ~16,000 | | total size | 1.3 TiB | | min size | 0 bytes | | max size | 12 GiB | | mean | 800 MiB | | median | 500 MiB | | total datapoints | ~200 billion | |------------------+--------------| The total number of datapoints is a very rough estimate. Proposed schema I'm planning on doing things "right" (i.e. normalizing the data like crazy) and so would have a runs table, a spectra table with a foreign key to runs, and a datapoints table with a foreign key to spectra. The 200 Billion datapoint question I am going to be analyzing across multiple spectra and possibly even multiple runs, resulting in queries which could touch millions of rows. Assuming I index everything properly (which is a topic for another question) and am not trying to shuffle hundreds of MiB across the network, is it remotely plausible for MySQL to handle this? UPDATE: additional info The scan data will be coming from files in the XML-based mzML format. The meat of this format is in the <binaryDataArrayList> elements where the data is stored. Each scan produces = 2 <binaryDataArray> elements which, taken together, form a 2-dimensional (or more) array of the form [[123.456, 234.567, ...], ...]. These data are write-once, so update performance and transaction safety are not concerns. My naïve plan for a database schema is: runs table | column name | type | |-------------+-------------| | id | PRIMARY KEY | | start_time | TIMESTAMP | | name | VARCHAR | |-------------+-------------| spectra table | column name | type | |----------------+-------------| | id | PRIMARY KEY | | name | VARCHAR | | index | INT | | spectrum_type | INT | | representation | INT | | run_id | FOREIGN KEY | |----------------+-------------| datapoints table | column name | type | |-------------+-------------| | id | PRIMARY KEY | | spectrum_id | FOREIGN KEY | | mz | DOUBLE | | num_counts | DOUBLE | | index | INT | |-------------+-------------| Is this reasonable?

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  • Choosing between a union and a boolean condition

    - by bread
    Does this require a UNION? SELECT vend_id, prod_id, prod_price FROM products WHERE prod_price <= 5 UNION SELECT vend_id, prod_id, prod_price FROM products WHERE vend_id IN (1001,1002); Or is it the same if you do it this way? SELECT vend_id, prod_id, prod_price FROM products WHERE prod_price <= 5 OR vend_id IN (1001,1002);

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  • mysql: get all rows into 1 column

    - by andufo
    hi, i have 3 tables: post (id_post, title) tag (id_tag, name) post_tag (id_post_tag, id_post, id_tag) Lets suppose that id_post 3 has 4 linked tags 1,2,3,4 (soccer, basket, tennis and golf). Is there a way to return something like this in ONE row? col 1 id_post = 3 col 2 tags = soccer basket tennis golf Thanks

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  • HQl equivalent of sql query

    - by kash
    String SQL_QUERY = "SELECT count(*) FROM (SELECT * FROM Url as U where U.pageType=" + 1 + " group by U.pageId having count(U.pageId) = 1)"; query = session.createQuery(SQL_QUERY); I am getting an error org.hibernate.hql.ast.QuerySyntaxException: unexpected token: ( near line 1, column 23 [ SELECT count() FROM (SELECT * FROM Url as U where U.pageType = 2 group by U.pageId having count(U.pageId) = 1)]

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  • Reading from an write-only(OUT) parameter in pl/sql

    - by sqlgrasshopper5
    When I tried writing to an read-only parameter(IN) of a function, Oracle complains with an error. But that is not the case when reading from an write-only(OUT) parameter of a function. Oracle silently allows this without any error. What is the reason for this behaviour?. The following code executes without any assignment happening to "so" variable: create or replace function foo(a OUT number) return number is so number; begin so := a; --no assignment happens here a := 42; dbms_output.put_line('HiYA there'); dbms_output.put_line('VAlue:' || so); return 5; end; / declare somevar number; a number := 6; begin dbms_output.put_line('Before a:'|| a); somevar := foo(a); dbms_output.put_line('After a:' || a); end; / Here's the output I got: Before a:6 HiYA there VAlue: After a:42

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  • Service Broker not working after database restore

    - by roryok
    Have a working Service Broker set up on a server, we're in the process of moving to a new server but I can't seem to get Service Broker set up on the new box. Have done the obvious (to me) things like Enabling Broker on the DB, dropping the route, services, contract, queues and even message type and re adding them, setting ALTER QUEUE with STATUS ON SELECT * FROM sys.service_queues gives me a list of the queues, including my own two, which show as activation_enabled, receive_enabled etc. Needless to say the queues aren't working. When I drop messages into them nothing goes in and nothing comes out. Any ideas? I'm sure there's something really obvious I've missed...

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  • How to do INSERT into a table records extracted from another table

    - by Martin
    I'm trying to write a query that extracts and transforms data from a table and then insert those data into another table. Yes, this is a data warehousing query and I'm doing it in MS Access. So basically I want some query like this: INSERT INTO Table2(LongIntColumn2, CurrencyColumn2) VALUES (SELECT LongIntColumn1, Avg(CurrencyColumn) as CurrencyColumn1 FROM Table1 GROUP BY LongIntColumn1); I tried but get a syntax error message. What would you do if you want to do this?

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  • Table for each region in MySQL

    - by King Wu
    There are four regions with more than one million records total. Should I create a table with a region column or a table for each region and combine them to get the top ranks? If I combine all four regions, none of my columns will be unique so I will need to also add an id column for my primary key. Otherwise, name, accountId & characterId would be candidate keys or should I just add an id column anyways. Table: ---------------------------------------------------------------- | name | accountId | iconId | level | characterId | updateDate | ----------------------------------------------------------------

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  • Why is this postgresql query so slow?

    - by user315975
    I'm no database expert, but I have enough knowledge to get myself into trouble, as is the case here. This query SELECT DISTINCT p.* FROM points p, areas a, contacts c WHERE ( p.latitude > 43.6511659465 AND p.latitude < 43.6711659465 AND p.longitude > -79.4677941889 AND p.longitude < -79.4477941889) AND p.resource_type = 'Contact' AND c.user_id = 6 is extremely slow. The points table has fewer than 2000 records, but it takes about 8 seconds to execute. There are indexes on the latitude and longitude columns. Removing the clause concering the resource_type and user_id make no difference. The latitude and longitude fields are both formatted as number(15,10) -- I need the precision for some calculations. There are many, many other queries in this project where points are compared, but no execution time problems. What's going on?

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  • mysql count rows and grop them by month

    - by user2661296
    I have a table called cc_calls and there I have many call records I want to count them and group them in months I have a timestamp called starttime and I can use that row to extract the month, also limit the count for 12 months the results should be like: Month Count January 768768 February 876786 March 987979 April 765765 May 898797 June 876876 July 786575 August 765765 September 689787 October 765879 November 897989 December 876876 Can anyone guide me or show me the mysql query that I need to get this result.

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  • Showing an image after loading it from sql database

    - by user330075
    I have a problem showing the image form database in a view Details and a ImageController. Inside the view I have: img src=Url.Action("GetFile","Image", new {id= Model.id}) and in controller: public FileContentResult GetFile(int idl) { //int idl = 32; SqlDataReader rdr; byte[] fileContent = null; ........... return File(,,); } When the view is called, function GetFile it just won't work. But if I cut out the parameter int id1 and I instantiate it as a variable it does work. public FileContentResult GetFile() { int idl = 32; SqlDataReader rdr; byte[] fileContent = null; ........... return File(,,); } Why?

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  • sqlite3 date operations when joining two tables in a view?

    - by duncan
    In short, how to add minutes to a datetime from an integer located in another table, in one select statement, by joining them? I have a table P(int id, ..., int minutes) and a table S(int id, int p_id, datetime start) I want to generate a view that gives me PS(S.id, P.id, S.start + P.minutes) by joining S.p_id=P.id The problem is, if I was generating the query from the application, I can do stuff like: select datetime('2010-04-21 14:00', '+20 minutes'); 2010-04-21 14:20:00 By creating the string '+20 minutes' in the application and then passing it to sqlite. However I can't find a way to create this string in the select itself: select p.*,datetime(s.start_at, formatstring('+%s minutes', p.minutes)) from p,s where s.p_id=p.id; Because sqlite as far the documentation tells, does not provide any string format function, nor can I see any alternative way of expressing the date modifiers.

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  • How to use SQL trigger to record the affected column's row number

    - by Freeman
    I want to have an 'updateinfo' table in order to record every update/insert/delete operations on another table. In oracle I've written this: CREATE TABLE updateinfo ( rnumber NUMBER(10), tablename VARCHAR2(100 BYTE), action VARCHAR2(100 BYTE), UPDATE_DATE date ) DROP TRIGGER TRI_TABLE; CREATE OR REPLACE TRIGGER TRI_TABLE AFTER DELETE OR INSERT OR UPDATE ON demo REFERENCING NEW AS NEW OLD AS OLD FOR EACH ROW BEGIN if inserting then insert into updateinfo(rnumber,tablename,action,update_date ) values(rownum,'demo', 'insert',sysdate); elsif updating then insert into updateinfo(rnumber,tablename,action,update_date ) values(rownum,'demo', 'update',sysdate); elsif deleting then insert into updateinfo(rnumber,tablename,action,update_date ) values(rownum,'demo', 'delete',sysdate); end if; -- EXCEPTION -- WHEN OTHERS THEN -- Consider logging the error and then re-raise -- RAISE; END TRI_TABLE; but when checking updateinfo, all rnumber column is zero. is there anyway to retrieve the correct row number?

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