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  • 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;

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  • When should I consider representing the primary-key ...?

    - by JMSA
    When should I consider representing the primary-key as classes? Should we only represent primary keys as classes when a table uses composite-key? For example: public class PrimaryKey { ... ... ...} Then private PrimaryKey _parentID; public PrimaryKey ParentID { get { return _parentID; } set { _parentID = value; } } And public void Delete(PrimaryKey id) {...} When should I consider storing data as comma-separated values in a column in a DB table rather than storing them in different columns?

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  • Lua SQL: peeking at cursors

    - by NP
    I am using LuaSQL, and query for a result set using con:execute(sql_stmt), which returns a cursor. How do I see if there is at least one row in that resultset, without doing a cursor:fetch to pop that first row?

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  • symfony 2 verify type of data stored in a single column

    - by GRafoKI
    In my DB I have a column 'own_product' that contains 2 values ( quantity and name) In my Edit form I want to check if the first field (quantity) is string and positive or not. I added a new column 'type-prod' (int , string) this is my controller : $request = $this->container->get('request'); if ($request->getMethod() == 'POST') { $formel = $request->query->get('edit_formal'); $type_value = $formel['own_product']; //case int $type_int= $this ->getDoctrine() ->getEntityManager() ->getRepository('DHG\WelcomeBundle\Entity\type-prod') ->findOneBy(array('type' => 'int')); //case string $type_string = $this ->getDoctrine() ->getEntityManager() ->getRepository('DHG\WelcomeBundle\Entity\type-prod') ->findOneBy(array('type' => 'string')); if (isset($type_value) && $type_int && $type_value > 0 && is_int($type_value)) { echo 'Success'; } else echo 'error' ; } Thank you !

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  • How to convert an application to be a database independent app ?

    - by Eslam
    I have a java web application that has informix DB as it's back end database , now i take a decision to make my app work with SqlServer so i changed all the informix related syntax into SqlServer, and i may take a decision in the future to switch into oracle so the pain will be repeated again and again, as a result i decided to make my application a DataBase independent one that's able to work with any DB vendor smoothly, but i have no idea till now about how to do that, so your ideas is welcomed.

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  • MDX: How to exclude ancestors from being returned in this query?

    - by wgpubs
    I have this MDX query: Exists([Group].[Group Hierarchy].allmembers, {[Group].[Group Full Name].&[121 - Group A], [Group].[Group Full Name].&[700000 - Group C]}) ... which works fine EXCEPT that it returns all of the ancestors of the specified groups as well. What I want is to return JUST the groups from the hierarchy with the specified Group Names (this is a type 2 dimension so there may be many at different levels). Any ideas?

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  • How do I Put Several Select Statements into Different Columns

    - by Russ Bradberry
    I basically have 7 select statement that I need to have the results output into separate columns. Normally I would use a crosstab for this but I need a fast efficient way to go about this as there are over 7 billion rows in the table. I am using the vertica database system. Below is an example of my statements: SELECT COUNT(user_id) AS '1' FROM event_log_facts WHERE date_dim_id=20100101 SELECT COUNT(user_id) AS '2' FROM event_log_facts WHERE date_dim_id=20100102 SELECT COUNT(user_id) AS '3' FROM event_log_facts WHERE date_dim_id=20100103 SELECT COUNT(user_id) AS '4' FROM event_log_facts WHERE date_dim_id=20100104 SELECT COUNT(user_id) AS '5' FROM event_log_facts WHERE date_dim_id=20100105 SELECT COUNT(user_id) AS '6' FROM event_log_facts WHERE date_dim_id=20100106 SELECT COUNT(user_id) AS '7' FROM event_log_facts WHERE date_dim_id=20100107

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  • 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 ;

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  • Observing social web behavior: to log or populate databases?

    - by jlafay
    When considering social web app architecture, is it a better approach to document user social patterns in a database or in logs? I thought for sure that behavior, actions, events would be strictly database stored but I noticed that some of the larger social sites out there also track a lot by logging what happens. Is it good practice to store prominent data about users in a database and since thousands of user actions can be spawned easily, should they be simply logged?

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  • 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

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  • how to get external variable value in dtsx package.

    - by Rishabh
    Hi, I am executing .dtsx package from c#, it was executing fine, if i am passing one variable value from c# code then how can i get it on .dtsx package for my ole db source query. Here is my c# code. string file = @"D:\CYNCZFuzzy\CYNCZFuzzy\Contact.dtsx"; package = app.LoadPackage(file, null); Variables vars = package.Variables; vars["User::parentContactID"].Value = 1028203; pkgResults = package.Execute(); string result = pkgResults.ToString(); I need this 1028203 value on my ole db source query, here my query. select cr.MasterContactID as ParentContactID, c.ID,C.FirstName, C.MiddleName, c.LastName, c.ID as FieldID from Contact c inner join ContactRelation cr on cr.SlaveContactID = c.ID where RelationshipID = 1 AND cr.MasterContactID = ? what I should write on ? for getting 1028203 value from c# page. Thanks in advance...

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  • same Linq for two tables

    - by Diana
    I need to do something like this, My two tables have the same signature, but different class so It suppose to work but it is not working. var myTable; if (booleanVariable == true) { myTable = table1; } else { myTable = table2; } var myLinq1 = from p in myTable join r in myOtherTable select p; In this case, I have to initialize myTable I have tried also, var myTable= table2; if (booleanVariable == true) { myTable = table1; } var myLinq1 = from p in myTable join r in myOtherTable select p; then var is type table2, then it can't be changed to table1 type. I need help, I don't want to make a copy paste of all the code. the linq query is huge, and it s nested with 5 or 6 queries. also I have to do this on 12 different methods. Thanks a lot for your help.

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  • Does clustered index on foreign key column increase join performance vs non-clustered ?

    - by alpav
    In many places it's recommended that clustered indexes are better utilized when used to select range of rows using BETWEEN statement. When I select joining by foreign key field in such a way that this clustered index is used, I guess, that clusterization should help too because range of rows is being selected even though they all have same clustered key value and BETWEEN is not used. Considering that I care only about that one select with join and nothing else, am I wrong with my guess ?

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  • Conditionally set a column to its default value in Postgres

    - by Evgeny
    I've got a PostgreSQL 8.4 table with an auto-incrementing, but nullable, integer column. I want to update some column values and, if this column is NULL then set it to its default value (which would be an integer auto-generated from a sequence), but I want to return its value in either case. So I want something like this: UPDATE mytable SET incident_id = COALESCE(incident_id, DEFAULT), other = 'somethingelse' WHERE ... RETURNING incident_id Unfortunately, this doesn't work - it seems that DEFAULT is special and cannot be part of an expression. What's the best way to do this?

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  • Adding Silverlight pages to existing ASP.net page??

    - by AJ
    Hi I know how to add SL page as a whole to existing ASP.net application. We have existing ASP.net page with few tabs. Each tab is a user control. We want to add another tab, which will host Silverlight content. Is it possible to add silverlight content in one of the tabs of a page? Any example links? Another way of putting up the same question : Is it possible to have an ASP.net page with top half as regular asp.net content and other half containing silverlight content? Please advise. Thanks AJ

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  • How Can I Reference Multiple Primary Keys For A Vector Type Primary Key

    - by AndreiC
    Hi, I have the following scenario: a table of projects and a table of persons, working on one or serveral projects. Also, I have a project id column (of type int), in the first table, which is a primary key there and I have a vector of project ids, as a column of type int, in my second table (persons), that references primary keys from the first table. What is the correct syntax for referencing multiple primary keys, from a vector foreign key. This is the way I am trying to create the table, but I am not sure what to place at the indicated line: CREATE TABLE Persons( Person_Id int, ..., ProjectsList int[], FOREIGN KEY (ProjectsList) REFERENCES Projects(Project_id) -- not sure what how to define the link here ); I hope my explanations are not over-complicated. Thank you in advance for helping!

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  • How to add active directory with sharepoint in the Virutal server ?

    - by pointlesspolitics
    I have a main server with windows server 2008 with active directory installed. Additionally, I have created the hyper-v virtual server with MOSS 2007 installed with dynamic ip address. I can access the sharepoint site as an intranet. How can I assign the access of all the active directory users and their profile to MOSS without adding them up manually ? If I am missing any information to provide please mention.

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  • Creating a foreign key in MySQL produces error:

    - by SnOrfus
    I'm trying to create a foreign key on a table in MySQL and I'm getting a strange error that there seems to be little info about in any of my searches. I'm creating the key with this (emitted from mysql workbench 5.2): ALTER TABLE `db`.`appointment` ADD CONSTRAINT `FK_appointment_CancellationID` FOREIGN KEY (`CancellationID` ) REFERENCES `db`.`appointment_cancellation` (`ID` ) ON DELETE NO ACTION ON UPDATE NO ACTION , ADD INDEX `FK_appointment_CancellationID` (`CancellationID` ASC) ; at which point I get the error: ERROR 1452: Cannot add or update a child row: a foreign key constraint fails (alarmtekcore., CONSTRAINT FK_lead_appointment_CancellationID FOREIGN KEY (CancellationID) REFERENCES lead_appointment_cancellation (`) I've checked here but there's no data in the table.

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  • How to select parent row only if has at least one child?

    - by Matt McCormick
    I have a simple one-to-many relationship. I would like to select rows from the parent only when they have at least one child. So, if there are no children, then the parent row is not returned in the result set. Eg. Parent: +--+---------+ |id| text | +--+---------+ | 1| Blah | | 2| Blah2 | | 3| Blah3 | +--+---------+ Children +--+------+-------+ |id|parent| other | +--+------+-------+ | 1| 1 | blah | | 2| 1 | blah2 | | 3| 2 | blah3 | +--+------+-------+ I want the results to be: +----+------+ |p.id|p.text| +----+------+ | 1 | Blah | | 2 | Blah2| +----+------+

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  • MySQL db Audit Trail Trigger

    - by Natkeeran
    I need to track changes (audit trail) in certain tables in a MySql Db. I am trying to implement the solution suggested here. I have an AuditLog Table with the following columns: AuditLogID, TableName, RowPK, FieldName, OldValue, NewValue, TimeStamp. The mysql stored procedure is the following (this executes fine, and creates the procedure): The call to the procedure such as: CALL addLogTrigger('ProductTypes', 'ProductTypeID'); executes, but does not create any triggers (see the image). SHOW TRIGGERS returns empty set. Please let me know what could be the issue, or an alternate way to implement this. DROP PROCEDURE IF EXISTS addLogTrigger; DELIMITER $ CREATE PROCEDURE addLogTrigger(IN tableName VARCHAR(255), IN pkField VARCHAR(255)) BEGIN SELECT CONCAT( 'DELIMITER $\n', 'CREATE TRIGGER ', tableName, '_AU AFTER UPDATE ON ', tableName, ' FOR EACH ROW BEGIN ', GROUP_CONCAT( CONCAT( 'IF NOT( OLD.', column_name, ' <=> NEW.', column_name, ') THEN INSERT INTO AuditLog (', 'TableName, ', 'RowPK, ', 'FieldName, ', 'OldValue, ', 'NewValue' ') VALUES ( ''', table_name, ''', NEW.', pkField, ', ''', column_name, ''', OLD.', column_name, ', NEW.', column_name, '); END IF;' ) SEPARATOR ' ' ), ' END;$' ) FROM information_schema.columns WHERE table_schema = database() AND table_name = tableName; END$ DELIMITER ;

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  • Should I use integer primary IDs?

    - by arthurprs
    For example, I always generate an auto-increment field for the users table, but I also specify a UNIQUE index on their usernames. There are situations that I first need to get the userId for a given username and then execute the desired query, or use a JOIN in the desired query. It's 2 trips to the database or a JOIN vs. a varchar index. Should I use integer primary IDs? Is there a real performance benefit on INT over small VARCHAR indexes?

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