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  • Need help with SQL Query

    - by StackOverflowNewbie
    Say I have 2 tables: Person - Id - Name PersonAttribute - Id - PersonId - Name - Value Further, let's say that each person had 2 attributes (say, gender and age). A sample record would be like this: Person->Id = 1 Person->Name = 'John Doe' PersonAttribute->Id = 1 PersonAttribute->PersonId = 1 PersonAttribute->Name = 'Gender' PersonAttribute->Value = 'Male' PersonAttribute->Id = 2 PersonAttribute->PersonId = 1 PersonAttribute->Name = 'Age' PersonAttribute->Value = '30' Question: how do I query this such that I get a result like this: 'John Doe', 'Male', '30'

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  • Hierarchical Data in MySQL is as fast as XML to retrieve?

    - by ajsie
    i've got a list of all countries - states - cities (- subcities/villages etc) in a XML file and to retrieve for example a state's all cities it's really quick with XML (using xml parser). i wonder, if i put all this information in mysql, is retrieving a state's all cities as fast as with XML? cause XML is designed to store hierarchical data while relational databases like mysql are not. the list contains like 500 000 entities. so i wonder if its as fast as XML using either of: Adjacency list model Nested Set model And which one should i use? Cause (theoretically) there could be unlimited levels under a state (i heard that adjacency isn't good for unlimited child-levels). And which is fastest for this huge dataset? Thanks!

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  • MS Access 2003 - Failure to create MDE file: error VBA is corrupt?

    - by Justin
    Ok so this is a brand new snag I have run into. I am trying to launch a new MDE from my source MDB file, and it is locking up Access. So in my mdb, I am first compacting and repairing, and then selecting create a new mde (just as I have done many times before). It looks like it is starting the process, but never gets to where it compacts when it is done, and access is not responding. So after I force close the app, I look in the folder where I am trying to create the MDE to and I see there is a new access db1 file there. If I try to open that it gives me an error that says file not found, and then it says the Visual Basic for Applications is corrupt. The thing is, I just made a very simple adjustment to the code since last launching an mde, and after this I double and triple checked it...its not that because its just a simple open this form and close this one addition. I did however have my source mdb file on a disc that I copied to my laptop, and then tried to re link the tables to the network drive (had them linked to other tables on my local drive so that I could develop offline)?? PLEASE HELP!!!

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  • PostgreSQL - best way to return an array of key-value pairs

    - by Matt W
    I'm trying to select a number of fields, one of which needs to be an array with each element of the array containing two values. Each array item needs to contain a name (character varying) and an ID (numeric). I know how to return an array of single values (using the ARRAY keyword) but I'm unsure of how to return an array of an object which in itself contains two values. The query is something like SELECT t.field1, t.field2, ARRAY(--with each element containing two values i.e. {'TheName', 1 }) FROM MyTable t I read that one way to do this is by selecting the values into a type and then creating an array of that type. Problem is, the rest of the function is already returning a type (which means I would then have nested types - is that OK? If so, how would you read this data back in application code - i.e. with a .Net data provider like NPGSQL?) Any help is much appreciated.

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  • Preg_match differences?

    - by sky
    Hi, i want to ask, what is the meaning or difference between these two line? if( preg_match_all('/\#([?-?À-ÿ?-??-?a-z0-9\-_]{1,50})/iu', $message, $matches, PREG_PATTERN_ORDER) ) { if( preg_match_all('/\#([?-?a-z0-9\-_\x{4e00}-\x{9fa5}]{1,50})/iu', $message, $matches, PREG_PATTERN_ORDER) ) { and what does the number 3 mean in this line? (Arrow pointing) if( preg_match_all('/\@([a-zA-Z0-9\-_\x{4e00}-\x{9fa5}]{->3,30})/u', $message, $matches, PREG_PATTERN_ORDER) ) { Thanks!

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  • More efficient method for grabbing all child units

    - by Hazior
    I have a table in SQL that links to itself through parentID. I want to find the children and their children and so forth until I find all the child objects. I have a recursive function that does this but it seems very ineffective. Is there a way to get sql to find all child objects? If so how?

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  • Non-Access or -base QBE tool?

    - by idbin.cath0br0
    Hello. I'm currently looking for a QBE tool that can execute queries on PostgreSQL or MySQL. OS doesn't really matter. Reason is that we've got to do QBE at school but I don't want to use neither Microsoft Access nor OpenOffice.org Base (lack of features). Any help would be appreciated.

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  • Yahoo Query Language Problem

    - by Damiano
    Hello everybody! Today, I've started with Yahoo Query Language. I would use it to retrive stocks details, so I'm talking about Yahoo Finance. I think there is a bug on this language. This is my query: select * from yahoo.finance.quoteslist where symbol='@^GSPC' I ALWAYS get 51 results! it's impossible, take a look at: http://it.finance.yahoo.com/q/cp?s=^GSPC There are 500 results! I also tried some paging parameters. select * from yahoo.finance.quoteslist(50,30) where symbol='@^GSPC' (to get from 50 to 80) select * from yahoo.finance.quoteslist(100) where symbol='@^GSPC' (to get the first 100 results) select * from yahoo.finance.quoteslist where symbol='@^GSPC' limit 30 offset 50 but ALWAYS the last stock is: <quote symbol="BBY"> <Symbol>BBY</Symbol> <LastTradePriceOnly>41.03</LastTradePriceOnly> <LastTradeDate>5/7/2010</LastTradeDate> <LastTradeTime>4:00pm</LastTradeTime> <Change>-0.48</Change> <Open>41.35</Open> <DaysHigh>42.35</DaysHigh> <DaysLow>39.60</DaysLow> <Volume>14129531</Volume> </quote> Why do I have this kind of problem? Thank you so much for your support! (P.S. I've tested it on Yahoo YQL console)

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  • Multiple rows update trigger

    - by sony
    If I have a statement that updates multiple rows, only the trigger will fire only on the first or last row that is being updated (not sure which one). I need to make a trigger that fires for ALL the records that are being updated into a particular table

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  • PDO update query with conditional?

    - by dmontain
    I have a PDO mysql that updates 3 fields. $update = $mypdo->prepare("UPDATE tablename SET field1=:field1, field2=:field2, field3=:field3 WHERE key=:key"); But I want field3 to be updated only when $update3 = true; (meaning that the update of field3 is controlled by a conditional statement) Is this possible to accomplish with a single query? I could do it with 2 queries where I update field1 and field2 then check the boolean and update field3 if needed in a separate query. //run this query to update only fields 1 and 2 $update_part1 = $mypdo->prepare("UPDATE tablename SET field1=:field1, field2=:field2 WHERE key=:key"); //if field3 should be update, run a separate query to update it separately if ($update3){ $update_part2 = $mypdo->prepare("UPDATE tablename SET field3=:field3 WHERE key=:key"); } But hopefully there is a way to accomplish this in 1 query?

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  • cached data base

    - by radi
    hi , in my project i need a tow tables each of it has about 2000 row , i want my application to be speed so my db should load into memory (cached) when the app start and before it close the db have to be saved on the disk . i am using java and i want to use sql

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  • sql 2008 express connection problems

    - by user163457
    Hi, I've just installed a fresh copy of SQL 2008 Express. before I did anything I opened Management Studio and successfully connected using Window Authentication. However I tried to run the following on the command line "telnet localhost 1433" and got the error "Could not open connection to the host, on port 1433: Connect failed" I checked netstat and there is nothing listening on port 1433. Before I go any further, is there a problem with the install? thanks, Shane

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  • What is the scope of TRANSACTION in Sql server

    - by Shantanu Gupta
    I was creating a stored procedure and i got stuck in the writing methodology of me and my collegue. I am using SQL Server 2005 I was writing Stored procedure like this BEGIN TRAN BEGIN TRY INSERT INTO Tags.tblTopic (Topic, TopicCode, Description) VALUES(@Topic, @TopicCode, @Description) INSERT INTO Tags.tblSubjectTopic (SubjectId, TopicId) VALUES(@SubjectId, @@IDENTITY) COMMIT TRAN END TRY BEGIN CATCH DECLARE @Error VARCHAR(1000) SET @Error= 'ERROR NO : '+ERROR_NUMBER() + ', LINE NO : '+ ERROR_LINE() + ', ERROR MESSAGE : '+ERROR_MESSAGE() PRINT @Error ROLLBACK TRAN END CATCH And my collegue was writing it like the below one BEGIN TRY BEGIN TRAN INSERT INTO Tags.tblTopic (Topic, TopicCode, Description) VALUES(@Topic, @TopicCode, @Description) INSERT INTO Tags.tblSubjectTopic (SubjectId, TopicId) VALUES(@SubjectId, @@IDENTITY) COMMIT TRAN END TRY BEGIN CATCH DECLARE @Error VARCHAR(1000) SET @Error= 'ERROR NO : '+ERROR_NUMBER() + ', LINE NO : '+ ERROR_LINE() + ', ERROR MESSAGE : '+ERROR_MESSAGE() PRINT @Error ROLLBACK TRAN END CATCH Here the only difference that you will find is the position of writing Begin TRAN. According to me the methodology of my collegue should not work when an exception occurs i.e. Rollback should not get executed because TRAN does'nt have scope. But when i tried to run both the code, both was working in the same way. I am confused to know how does TRANSACTION works. Is it scope free or what ?

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  • Any disadvantages to this tagging approach

    - by donpal
    I have a table of tags ID tag --- ------ 1 tagt 2 tagb 3 tagz 4 tagn In my items table, I'm using those tags in serialized format, comma delimited ID field1 tags ---- ------ ----- 1 value1 tagt,tagb 2 value2 tagb 3 value3 tagb,tagn 4 value4 When I need to find items that have this tag, I plan to deserialize the tags. But I'm not actually sure how to do it, and if it's better to have a third table for associations instead between the tags and the items.

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  • mysql GROUP_CONCAT

    - by user301766
    I want to list all users with their corropsonding user class. Here are simplified versions of my tables CREATE TABLE users ( user_id INT NOT NULL AUTO_INCREMENT, user_class VARCHAR(100), PRIMARY KEY (user_id) ); INSERT INTO users VALUES (1, '1'), (2, '2'), (3, '1,2'); CREATE TABLE classes ( class_id INT NOT NULL AUTO_INCREMENT, class_name VARCHAR(100), PRIMARY KEY (class_id) ); INSERT INTO classes VALUES (1, 'Class 1'), (2, 'Class 2'); And this is the query statement I am trying to use but is only returning the first matching user class and not a concatenated list as hoped. SELECT user_id, GROUP_CONCAT(DISTINCT class_name SEPARATOR ",") AS class_name FROM users, classes WHERE user_class IN (class_id) GROUP BY user_id; Actual Output +---------+------------+ | user_id | class_name | +---------+------------+ | 1 | Class 1 | | 2 | Class 2 | | 3 | Class 1 | +---------+------------+ Wanted Output +---------+---------------------+ | user_id | class_name | +---------+---------------------+ | 1 | Class 1 | | 2 | Class 2 | | 3 | Class 1, Class 2 | +---------+---------------------+ Thanks in advance

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  • SQL query for selecting the firsts in a series by cloumn

    - by SP
    I'm having some trouble coming up with a query for what I am trying to do. I've got a table we'll call 'Movements' with the following columns: RecID(Key), Element(f-key), Time(datetime), Room(int) The table is holding a history of Movements for the Elements. One record contains the element the record is for, the time of the recorded location, and the room it was in at that time. What I would like are all records that indicate that an Element entered a room. That would mean the first (by time) entry for any element in a series of movements for that element in the same room. The input is a room number and a time. IE, I would like all of the records indicating that any Element entered room X after time Y. The closest I came was this Select Element, min(Time) from Movements where Time > Y and Room = x group by Element This will only give me one room entry record per Element though (If the Element has entered the room X twice since time Y I'll only get the first one back) Any ideas? Let me know if I have not explained this clearly. I'm using MS SQLServer 2005.

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  • How to handle large dataset with JPA (or at least with Hibernate)?

    - by Roman
    I need to make my web-app work with really huge datasets. At the moment I get either OutOfMemoryException or output which is being generated 1-2 minutes. Let's put it simple and suppose that we have 2 tables in DB: Worker and WorkLog with about 1000 rows in the first one and 10 000 000 rows in the second one. Latter table has several fields including 'workerId' and 'hoursWorked' fields among others. What we need is: count total hours worked by each user; list of work periods for each user. The most straightforward approach (IMO) for each task in plain SQL is: 1) select Worker.name, sum(hoursWorked) from Worker, WorkLog where Worker.id = WorkLog.workerId group by Worker.name; //results of this query should be transformed to Multimap<Worker, Long> 2) select Worker.name, WorkLog.start, WorkLog.hoursWorked from Worker, WorkLog where Worker.id = WorkLog.workerId; //results of this query should be transformed to Multimap<Worker, Period> //if it was JDBC then it would be vitally //to set resultSet.setFetchSize (someSmallNumber), ~100 So, I have two questions: how to implement each of my approaches with JPA (or at least with Hibernate); how would you handle this problem (with JPA or Hibernate of course)?

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  • How can I execute a SQL query in emacs lisp?

    - by Chris R
    I want to execute an SQL query and get its result in elisp: (let ((results (do-sql-query "SELECT * FROM a_table"))) (do-something-with results)) I'm using Postgres, and I already know all of my connection information (host, username, password, db et al) I just want to execute the query and get the result back, synchronously.

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  • Transaction Isolation on select, insert, delete

    - by Bradford
    What could possibly go wrong with the following transaction if executed by concurrent users in the default isolation level of READ COMMITTED? BEGIN TRANSACTION SELECT * FROM t WHERE pid = 10 and r between 40 and 60 -- ... this returns tid = 1, 3, 5 -- ... process returned data ... DELETE FROM t WHERE tid in (1, 3, 5) INSERT INTO t (tid, pid, r) VALUES (77, 10, 35) INSERT INTO t (tid, pid, r) VALUES (78, 10, 37) INSERT INTO t (tid, pid, r) VALUES (79, 11, 39) COMMIT

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  • Using Entity Framework, how do I specify a sort on a navagation property?

    - by Jared
    I have two tables: [Category], [Item]. They are connected by a join table: [CategoryAndItem]. It has two primary key fields: [CategoryKey], [ItemKey]. Foreign keys exist appropriately and Entity has no problem pulling this in and creating the correct navigation properties that connect the entity objects. Basically each category can have multiple items, and items can be in multiple categories. The problem is that the order of items is specified per category, so that a particular item might be third in one category but fifth in another. In the past, I have added a [Sequence] field to the join table and modified the stored procedure to handle it. But since Entity is replacing my stored procedures, I need to figure out how to make Entity handle the sequence. Any suggestions?

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  • Using memory-based cache together with conventional cache

    - by Industrial
    Hi! Here's the deal. We would have taken the complete static html road to solve performance issues, but since the site will be partially dynamic, this won't work out for us. What we have thought of instead is using memcache + eAccelerator to speed up PHP and take care of caching for the most used data. Here's our two approaches that we have thought of right now: Using memcache on all<< major queries and leaving it alone to do what it does best. Usinc memcache for most commonly retrieved data, and combining with a standard harddrive-stored cache for further usage. The major advantage of only using memcache is of course the performance, but as users increases, the memory usage gets heavy. Combining the two sounds like a more natural approach to us, even though the theoretical compromize in performance. Memcached appears to have some replication features available as well, which may come handy when it's time to increase the nodes. What approach should we use? - Is it stupid to compromize and combine the two methods? Should we insted be focusing on utilizing memcache and instead focusing on upgrading the memory as the load increases with the number of users? Thanks a lot!

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