Search Results

Search found 31931 results on 1278 pages for 'sql statement'.

Page 658/1278 | < Previous Page | 654 655 656 657 658 659 660 661 662 663 664 665  | Next Page >

• Survey Data Model - How to avoid EAV and excessive denormalization?

  - by AlexDPC

  Hi everyone, My database skills are mediocre at best and I have to design a data model for survey data. I have spent some thoughts on this and right now I feel that I am stuck between some kind of EAV model and a design involving hundreds of tables, each with hundreds of columns (and thousands of records). There must be a better way to do this and I hope that the wise folks on this forum can help me. I have already searched various forums, but I couldn't really find a solution. If it has already been given elsewhere, please excuse me and provide me with a link so I can read it up. Some assumptions about the data I have to deal with: Each survey consists of 1 to n questionnaires Each questionnaire consists of 100-2,000 questions (please ignore that 2,000 questions really sound like a lot to answer...) Questions can be of various types: multiple-choice, free text, a number (like age, income, percentages, ...) Each survey involves 10-200 countries (These are not the respondents. The respondents are actually people in the countries.) Depending on the type of questionnaire, each questionnaire is answered by 100-20,000 respondents per country. A country can adapt the questionnaires for a survey, i.e. add, remove or edit questions The data for one country is gathered in a separate database in that country. There is no possibility for online integration from the start. The data for all countries has to be integrated later. This means for example, if a country has deleted a question, that data must somehow be derived from what they sent in order to achieve a uniform design across all countries I will have to write the integration and cleaning software, which will need to work with every country's data In the end the data needs to be exported to flat files, one rectangular grid per country and questionnaire. I have already discussed this topic with people from various backgrounds and have not come to a good solution yet. I mainly got two kinds of opinions. The domain experts, who are used to working with flat files (spreadsheet-style) for data processing and analysis vote for a denormalized structure with loads of tables and columns as I described above (1 table per country and questionnaire). This sounds terrible to me, because I learned that wide tables are to be avoided, it will be annoying to determine which columns are actually in a table when working with it, the database will become cluttered with hundreds of tables (or I even need to set up multiple databases, each with a similar yet a bit differetn design), etc. O-O-programmers vote for a strongly "normalized" design, which would effectively lead to a central table containing all the answers from all respondents to all questions. This table would either need to contain a column of type sql_variant type or multiple answer columns with different types to store answers of different types (multiple choice, free text, ..). The former would essentially be a EAV model. I tend to follow Joe Celko here, who strongly discourages its use (he calls it OTLT or "One True Lookup Table"). The latter would imply that each row would contain null cells for the not applicable types by design. Another alternative I could think of would be to create one table per answer type, i.e., one for multiple-choice questions, one for free text questions, etc.. That's not so generic, it would lead to a lot of union joins, I think and I would have to add a table if a new answer type is invented. Sorry for boring you with all this text and thank you for your input! Cheers, Alex PS: I asked the same question here: http://www.eggheadcafe.com/community/aspnet/13/10242616/survey-data-model--how-to-avoid-eav-and-excessive-denormalization.aspx

  Read the article

• MySQL Query: Winning Auction Bid

  - by mabwi

  I have a small Bidding system that I'm using for a fantasy auction draft. I'm trying to use the below query to pull up the max bids on each player. However, it's not actually giving me the max bid, it's just giving me the first one entered in to the database. SELECT Bid.id FROM bids AS Bid WHERE Bid.active =1 GROUP BY player_id HAVING MAX( Bid.amount ) Here's the Bid table layout, in case it helps: CREATE TABLE IF NOT EXISTS `bids` ( `id` int(10) NOT NULL AUTO_INCREMENT, `user_id` int(10) NOT NULL, `player_id` int(10) NOT NULL, `amount` int(6) NOT NULL, `timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP, `winning_bid` int(1) NOT NULL DEFAULT '0', `active` int(1) NOT NULL DEFAULT '1', PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 ;

  Read the article

• How do I convert int? into int

  - by Richard77

  Hello, I've create a SPROC that saves an object and returns the id of the new object saved. Now, I'd like to return an int not an int? public int Save(Contact contact) { int? id; context.Save_And_SendBackID(contact.FirstName, contact.LastName, ref id); //How do I return an int instead of an int? } Thanks for helping

  Read the article

• Should I return IEnumerable<T> or IQueryable<T> from my DAL?

  - by Gary '-'

  I know this could be opinion, but I'm looking for best practices. As I understand, IQueryable implements IEnumerable, so in my DAL, I currently have method signatures like the following: IEnumerable<Product> GetProducts(); IEnumerable<Product> GetProductsByCategory(int cateogoryId); Product GetProduct(int productId); Should I be using IQueryable here? What are the pros and cons of either approach? Note that I am planning on using the Repository pattern so I will have a class like so: public class ProductRepository { DBDataContext db = new DBDataContext(<!-- connection string -->); public IEnumerable<Product> GetProductsNew(int daysOld) { return db.GetProducts() .Where(p => p.AddedDateTime > DateTime.Now.AddDays(-daysOld )); } } Should I change my IEnumerable<T> to IQueryable<T>? What advantages/disadvantages are there to one or the other?

  Read the article

• how to Invoke User-Defined Functions That Return a Table Data Type

  - by nectar

  here my code- create function dbo.emptable() returns Table as return (select id, name, salary from employee) go select dbo.emptable() error: Msg 4121, Level 16, State 1, Line 1 Cannot find either column "dbo" or the user-defined function or aggregate "dbo.emptable", or the name is ambiguous. while when I run sp_helptext emptable it shows- create function dbo.emptable() returns Table as return (select id, name, salary from employee) it means function exists in database then why it is giving such error?

  Read the article

• Does the order of columns matter in a group by clause?

  - by Jeff Meatball Yang

  If I have two columns, one with very high cardinality and one with very low cardinality (unique # of values), does it matter in which order I group by? Here's an example: select dimensionName, dimensionCategory, sum(someFact) from SomeFact f join SomeDim d on f.dimensionKey = d.dimensionKey group by d.dimensionName, -- large number of unique values d.dimensionCategory -- small number of unique values Are there situations where it matters?

  Read the article

• jruby hangs on connection to sqlserver

  - by Christopher Dancy

  Jruby is hanging on connection to sqlserver and I cannot figure out why. Here is my code ... puts "make connection" ActiveRecord::Base.establish_connection( :adapter => 'jdbc', :driver => 'com.microsoft.jdbc.sqlserver.SQLServerDriver', :url => 'jdbc:sqlserver://test:1433;databaseName=test;integratedSecurity=true', :username=>'test', :password=>'test' ) puts "connected" fish = ActiveRecord::Base.connection.execute("SELECT * FROM users") puts "query ok" the code spits out "make connection" and then "connected" but never reaches "query ok" any ideas?

  Read the article

• The Next-gen Databases

  - by Randin

  I'm learning traditional Relational Databases (with PostgreSQL) and doing some research I've come across some new types of databases. CouchDB, Drizzle, and Scalaris to name a few, what is going to be the next database technologies to deal with?

  Read the article

• Complicated SQL query

  - by Yandawl

  Please bare with me this is difficult to explain xD http://img90.imageshack.us/i/croppercapture1.png/ This is based on an undergraduate degree course where a student takes many units (say 4 core units and 1 optional unit per year). tblAwardCoreUnits and tblAwardOptUnits store which units are optional and core for which award, hence the relationship to tblAward and tblStudentCoreUnits and tblStudentOptUnits store the particular instances of those units which a particular student is taking. Secondly, a unit can have multiple events (say a lecture and a unit) and each of those events has sessions in which a student can attend, hence tblEvents, tblSessions and tblAttendances. The query I am trying to produce is to get a list of all level one students, grouped by their award that lists the percentage of attendances in all the units in the current level. I've tried and tried with this and the following is the best I've managed to come up with so far... I'd REALLY appreciate any help you can give with this! SELECT tblStudents.enrolmentNo, tblStudents.forename, tblStudents.surname, tblAwards.title, (SELECT COUNT((tblAttendances.attended + tblAttendances.authorisedAbsence)) AS SumOfAttendances FROM tblAttendances INNER JOIN (tblStudents ON tblStudents.enrolmentNo = tblAttendances.enrolmentNo)) / FROM tblUnits, tblAwards INNER JOIN ((tblStudents INNER JOIN tblStudentOptUnit ON tblStudents.studentID = tblStudentOptUnit.studentID) INNER JOIN tblStudentCoreUnit ON tblStudents.studentID = tblStudentCoreUnit.studentID) ON tblAwards.awardID = tblStudents.awardID WHERE (((tblStudents.level)="1") AND ((tblStudents.status)="enrolled")) GROUP BY tblAwards.title ORDER BY tblStudents.forname;

  Read the article

• Firebird: How to assign id to existing rows from newly added generator

  - by Aldo

  I have a table which already contains some rows and does not have a primary key. I want to add a primary key now, but for that I need to set unique values for the primary key field of the existing rows. How can this be done, using the newly added generator?

  Read the article

• Can primary index be a CHAR in MySQL?

  - by FFish

  My primary indexes are unique reference numbers like 002345 and 000023. If I format them as integers I loose my zero's. They need to be 6 digits. Can I use CHAR? I don't need any auto increments.

  Read the article

• Can I join two tables whereby the joined table is sorted by a certain column?

  - by Ferdy

  I'm not much of a database guru so I need some help on a query I'm working on. In my photo community project I want to richly visualize tags by not only showing the tag name and counter (# of images inside them), I also want to show a thumb of the most popular image inside the tag (most karma). The table setup is as follow: Image table holds basic image metadata, important is the karma field Imagefile table holds multiple entries per image, one for each format Tag table holds tag definitions Tag_map table maps tags to images In my usual trial and error query authoring I have come this far: SELECT * FROM (SELECT tag.name, tag.id, COUNT(tag_map.tag_id) as cnt FROM tag INNER JOIN tag_map ON (tag.id = tag_map.tag_id) INNER JOIN image ON tag_map.image_id = image.id INNER JOIN imagefile on image.id = imagefile.image_id WHERE imagefile.type = 'smallthumb' GROUP BY tag.name ORDER BY cnt DESC) as T1 WHERE cnt > 0 ORDER BY cnt DESC [column clause of inner query snipped for the sake of simplicity] This query gives me somewhat what I need. The outer query makes sure that only tags are returned for which there is at least 1 image. The inner query returns the tag details, such as its name, count (# of images) and the thumb. In addition, I can sort the inner query as I want (by most images, alphabetically, most recent, etc) So far so good. The problem however is that this query does not match the most popular image (most karma) of the tag, it seems to always take the most recent one in the tag. How can I make sure that the most popular image is matched with the tag?

  Read the article

• LINQtoSQL: Query to return List<String>

  - by ctrlShiftBryan

  I have a LINQ query that returns some object like this... var query = from c in db.Customers where ... select c; Then I do this List<String> list = new List<String>(); foreach (ProgramLanguage c in query) { //GetUL returns a String list.Add(GetUL(c.Property,c.Property2)); } Is there a way to combine into something list this? var query = from c in db.Customers where ... select new { GetUL(c.Property,c.Property2) }).ToList<String>();

  Read the article

• Selecting all but one field?

  - by gsquare567

  instead of SELECT * FROM mytable, i would like to select all fields EXCEPT one (namely, the 'serialized' field, which stores a serialized object). this is because i think that losing that field will speed up my query by a lot. however, i have so many fields and am quite the lazy guy. is there a way to say... `SELECT ALL_ROWS_EXCEPT(serialized) FROM mytable` ? thanks!

  Read the article

• Oracle - Updating one column or another based on a condition

  - by z-dan

  I want to update a record in a table but based on a condition I will either update one column or another but I do not want to have 2 separate statements because the statements are very long and detailed. Here is the basic idea with over simplification to get to the point. PROCEDURE Animal_something(p_updater VARCHAR2) begin if p_updater = 'person' then -- I want to update the modified_by else -- if p_updater = 'a process' I want to update modified_by_process Update table_creatures set animal_type = 'Dog , **modified_by** = 'Bob' **or do this** **modified_by_process =** 'creature_package' where animal_legs = '4' I don't want: if p_updater = 'person' then Update table_creatures set animal_type = 'Dog , modified_by = 'Bob' where animal_legs = '4'; else Update table_creatures set animal_type = 'Dog , modified_by_process = 'creature_package' where animal_legs = '4'; end;

  Read the article

• Equivalent of mysql_insert_id() for Postgresql ? [closed]

  - by xRobot

  Possible Duplicate: mysql_insert_id alternative for postgresql Is there a Postgresql equivalent of mysql_insert_id() to get the ID generated in the last query ??

  Read the article

• MySQL break out group clause from subquery

  - by Anton Gildebrand

  Here is my query SELECT COALESCE(js.name,'Lead saknas'), count(j.id) FROM jobs j LEFT JOIN job_sources js ON j.job_source=js.id LEFT JOIN (SELECT * FROM quotes GROUP BY job_id) q ON j.id=q.job_id GROUP BY j.job_source The problem is that it's allowed for each job to have more than one quote. Because of that i group the quotes by job_id. Now sure, this works. But i don't like the solution with a subquery. How can i break out the group clause from the subquery to the main query? I have tried to add q.job_id to the main group clause, both before and after the existing one but don't get the same results.

  Read the article

• Is SELECT INTO able to affect data from its original table during UPDATE

  - by driveby

  Whilst asking this question asp.net scheduling timed events user murph posted some insightful information: Point about this is that its very, very simple - you have an process for exchange that is performing a clearly defined task and you have a high frequency task that is not doing anything particularly complex, its a straightforward query (select from table where sent = false and send at < value) - probably into temporary table so that you can run a single query update after you've done the sends - that you can optimise the index for. You're not trying to queue up a huge pile of event triggers, just one that fires once a minute and processes things that are due. Is it possible to SELECT data from table X INTO table Y and have the UPDATES that are performed on table Y pushed into table X? I guess the alternative would be that the data gets updated in table Y then an update command can be run on table X based on the data in table Y. What would be the advantage of selecting into another table? Thank you,

  Read the article

• Accessing non-related entities in LinqToSql entity classes

  - by Chris Johnson

  In LinqToSql, if I want to access a non-related entity in an entity partial class, how do I do this without creating a new DataContext? Here's the scenario: I have the tables Client, IssueType and ClientIssueType. A Client may specify a list of IssueTypes if they do not want to use the default IssueTypes. I have the default IssueTypes in the ClientIssueType table with a ClientId of null. In my Client partial I'd like to try to retrieve all IssueTypes, and if none are found, return all default IssueTypes. The only way I can see of accessing the IssueTypes with a null ClientId is by accessing the table through a new DataContext, which is problematic once I want to start assigning them to Issues. Where am I going wrong?

  Read the article

• Sql CLR calling webservice throws exception

  - by TonyP

  I have clr stored procedure that calls a Webservice method. Webmethod in turn call a com object .. and do some processing on a remote Unix server. When I invoke webmethod by it self it works fine. But when called from the CLR I get the following exception.. What am I doing wrong ? Msg 6522, Level 16, State 1, Procedure PrintOa, Line 0 A .NET Framework error occurred during execution of user-defined routine or aggregate "PrintOa": System.Security.HostProtectionException: Attempted to perform an operation that was forbidden by the CLR host. The protected resources (only available with full trust) were: All The demanded resources were: Synchronization System.Security.HostProtectionException: at System.Reflection.MethodBase.PerformSecurityCheck(Object obj, RuntimeMethodHandle method, IntPtr parent, UInt32 invocationFlags) at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at System.Diagnostics.TraceUtils.GetRuntimeObject(String className, Type baseType, String initializeData) at System.Diagnostics.TypedElement.BaseGetRuntimeObject() at System.Diagnostics.ListenerElement.GetRuntimeObject() at System.Diagnostics.ListenerElementsCollection.GetRuntimeObject() at System.Diagnostics.TraceInternal.get_Listeners() at System.Diagnostics.TraceInternal.WriteLine(Object value) at System.Diagnostics.Debug.WriteLine(Object value) at BaaNOA.PrintOA(String trid)

  Read the article

• What's the difference between tsql and isql?

  - by wamp

  I saw this in this post,and is really confused

  Read the article

• Scalable Database Tagging Schema

  - by Longpoke

  EDIT: To people building tagging systems. Don't read this. It is not what you are looking for. I asked this when I wasn't aware that RDBMS all have their own optimization methods, just use a simple many to many scheme. I have a posting system that has millions of posts. Each post can have an infinite number of tags associated with it. Users can create tags which have notes, date created, owner, etc. A tag is almost like a post itself, because people can post notes about the tag. Each tag association has an owner and date, so we can see who added the tag and when. My question is how can I implement this? It has to be fast searching posts by tag, or tags by post. Also, users can add tags to posts by typing the name into a field, kind of like the google search bar, it has to fill in the rest of the tag name for you. I have 3 solutions at the moment, but not sure which is the best, or if there is a better way. Note that I'm not showing the layout of notes since it will be trivial once I get a proper solution for tags. Method 1. Linked list tagId in post points to a linked list in tag_assoc, the application must traverse the list until flink=0 post: id, content, ownerId, date, tagId, notesId tag_assoc: id, tagId, ownerId, flink tag: id, name, notesId Method 2. Denormalization tags is simply a VARCHAR or TEXT field containing a tab delimited array of tagId:ownerId. It cannot be a fixed size. post: id, content, ownerId, date, tags, notesId tag: id, name, notesId Method 3. Toxi (from: http://www.pui.ch/phred/archives/2005/04/tags-database-schemas.html, also same thing here: http://stackoverflow.com/questions/20856/how-do-you-recommend-implementing-tags-or-tagging) post: id, content, ownerId, date, notesId tag_assoc: ownerId, tagId, postId tag: id, name, notesId Method 3 raises the question, how fast will it be to iterate through every single row in tag_assoc? Methods 1 and 2 should be fast for returning tags by post, but for posts by tag, another lookup table must be made. The last thing I have to worry about is optimizing searching tags by name, I have not worked that out yet. I made an ASCII diagram here: http://pastebin.com/f1c4e0e53

  Read the article

• asp code for upload data

  - by vicky

  hello everyone i have this code for uploading an excel file and save the data into database.I m not able to write the code for database entry. someone please help <% if (Request("FileName") <> "") Then Dim objUpload, lngLoop Response.Write(server.MapPath(".")) If Request.TotalBytes > 0 Then Set objUpload = New vbsUpload For lngLoop = 0 to objUpload.Files.Count - 1 'If accessing this page annonymously, 'the internet guest account must have 'write permission to the path below. objUpload.Files.Item(lngLoop).Save "D:\PrismUpdated\prism_latest\Prism\uploadxl\" Response.Write "File Uploaded" Next Dim FSYSObj, folderObj, process_folder process_folder = server.MapPath(".") & "\uploadxl" set FSYSObj = server.CreateObject("Scripting.FileSystemObject") set folderObj = FSYSObj.GetFolder(process_folder) set filCollection = folderObj.Files Dim SQLStr SQLStr = "INSERT ALL INTO TABLENAME " for each file in filCollection file_name = file.name path = folderObj & "\" & file_name Set objExcel_chk = CreateObject("Excel.Application") Set ws1 = objExcel_chk.Workbooks.Open(path).Sheets(1) row_cnt = 1 'for row_cnt = 6 to 7 ' if ws1.Cells(row_cnt,col_cnt).Value <> "" then ' col = col_cnt ' end if 'next While (ws1.Cells(row_cnt, 1).Value <> "") for col_cnt = 1 to 10 SQLStr = SQLStr & "VALUES('" & ws1.Cells(row_cnt, 1).Value & "')" next row_cnt = row_cnt + 1 WEnd 'objExcel_chk.Quit objExcel_chk.Workbooks.Close() set ws1 = nothing objExcel_chk.Quit Response.Write(SQLStr) 'set filobj = FSYSObj.GetFile (sub_fol_path & "\" & file_name) 'filobj.Delete next End if End If plz tell me how to save the following excel data to the oracle databse.any help would be appreciated

  Read the article

• What's faster? select [object] or select new {[object].value1, [object].value2} with linq

  - by Darcy

  I was hoping some of you guru's out there know the answer to this question. Which is faster? A or B A: var item = from d in database select d; B: var item = from d in database select new {d.item1, d.item2}; SEEMINGLY, it seems like selecting part of the table object would be faster than selecting the entire object, but something tells me its not necessarily the case.

  Read the article

• Can I recover lost data from an .mdf or .ldf file?

  - by goel-kshamata

  I have my .mdf and .ldf database files for a database named dbtrial. I accidentally deleted the data in one table. Is there any way to do this?

  Read the article

< Previous Page | 654 655 656 657 658 659 660 661 662 663 664 665  | Next Page >