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• Opinions on sensor / reading / alert database design

  - by Mark

  I've asked a few questions lately regarding database design, probably too many ;-) However I beleive I'm slowly getting to the heart of the matter with my design and am slowly boiling it down. I'm still wrestling with a couple of decisions regarding how "alerts" are stored in the database. In this system, an alert is an entity that must be acknowledged, acted upon, etc. Initially I related readings to alerts like this (very cut down) : - [Location] LocationId [Sensor] SensorId LocationId UpperLimitValue LowerLimitValue [SensorReading] SensorReadingId Value Status Timestamp [SensorAlert] SensorAlertId [SensorAlertReading] SensorAlertId SensorReadingId The last table is associating readings with the alert, because it is the reading that dictate that the sensor is in alert or not. The problem with this design is that it allows readings from many sensors to be associated with a single alert - whereas each alert is for a single sensor only and should only have readings for that sensor associated with it (should I be bothered that the DB allows this though?). I thought to simplify things, why even bother with the SensorAlertReading table? Instead I could do this: [Location] LocationId [Sensor] SensorId LocationId [SensorReading] SensorReadingId SensorId Value Status Timestamp [SensorAlert] SensorAlertId SensorId Timestamp [SensorAlertEnd] SensorAlertId Timestamp Basically I'm not associating readings with the alert now - instead I just know that an alert was active between a start and end time for a particular sensor, and if I want to look up the readings for that alert I can do. Obviously the downside is I no longer have any constraint stopping me deleting readings that occurred during the alert, but I'm not sure that the constraint is neccessary. Now looking in from the outside as a developer / DBA, would that make you want to be sick or does it seem reasonable? Is there perhaps another way of doing this that I may be missing? Thanks. EDIT: Here's another idea - it works in a different way. It stores each sensor state change, going from normal to alert in a table, and then readings are simply associated with a particular state. This seems to solve all the problems - what d'ya think? (the only thing I'm not sure about is calling the table "SensorState", I can't help think there's a better name (maybe SensorReadingGroup?) : - [Location] LocationId [Sensor] SensorId LocationId [SensorState] SensorStateId SensorId Timestamp Status IsInAlert [SensorReading] SensorReadingId SensorStateId Value Timestamp There must be an elegant solution to this!

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• Multiple Columns as Primary keys

  - by rockbala

  CREATE TABLE Persons ( P_Id int NOT NULL, LastName varchar(255) NOT NULL, FirstName varchar(255), Address varchar(255), City varchar(255), CONSTRAINT pk_PersonID PRIMARY KEY (P_Id,LastName) ) The above example is taken from w3schools. From the above example, my understanding is that both P_Id, LastName together represents a Primary Key for the table Persons, correct ? Another question is why would some one want to use multiple columns as Primary keys instead of a single column ? How many such columns can be used in together as Primary key in a given table ? Thanks Balaji S

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• Django unique_together error and validation

  - by zubinmehta

  class Votes(models.Model): field1 = models.ForeignKey(Blah1) field2 = models.ForeignKey(Blah2) class Meta: unique_together = (("field1","field2"),) I am using this code as one of my models. Now i wanted to know two things: 1. It doesn't show any error and it saved an entry which wasn't unique together; So is the piece of code correct? 2. How can the unique_together constraint be be validated?

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• error in mysql syntax

  - by fusion

  while executing the following query, i get an error that there's an error in the syntax near line 9. since i'm using mysql workbench, i can't really figure out what could be wrong: CREATE TABLE IF NOT EXISTS `proquotes`.`thquotes` ( `idQuotes` INT NOT NULL AUTO_INCREMENT , `vAuthorID` VARCHAR(8) CHARACTER SET 'utf8' NOT NULL , `vAuthor` VARCHAR(45) CHARACTER SET 'utf8' NOT NULL , `cQuotes` MEDIUMTEXT CHARACTER SET 'utf8' NOT NULL , `cArabic` MEDIUMTEXT CHARACTER SET 'utf8' NOT NULL , `vReference` VARCHAR(100) CHARACTER SET 'utf8' NOT NULL , PRIMARY KEY (`idQuotes`) , INDEX `vAuthorID` () , CONSTRAINT `vAuthorID` FOREIGN KEY () REFERENCES `proquotes`.`author_info` () ON DELETE NO ACTION ON UPDATE NO ACTION) DEFAULT CHARACTER SET = utf8;

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• convert a number to the shortest possible character string while retaining uniqueness

  - by alumb

  I have a list of digits, say "123456", and I need to map it to a string, any string. The only constraint on the map functions are: each list of digits must map to a unique character string (this means the string can be arbitrarily long) character string can only contain 0-9, a-z, A-Z What map function would produce the shortest strings? Solutions in JavaScript are preferred. note: Clearly the simplest solution is to use the original list of digits, so make sure you solution does better than that.

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• Web Safe Area (optimal resolution) for web app design

  - by M.A.X

  I'm in the process of designing a new web app and I'm wondering for what 'web safe area' should I optimize the app layout and design. I did some investigation and thinking on my own but wanted to share this to see what the general opinion is. Here is what I found: Optimal Display Resolution: w3schools web stats seems to be the most referenced source (however they state that these are results from their site and is biased towards tech savvy users) http://www.w3counter.com/globalstats.php (aggregate data from something like 15,000 different sites that use their tracking services) StatCounter Global Stats Display Resolution (Stats are based on aggregate data collected by StatCounter on a sample exceeding 15 billion pageviews per month collected from across the StatCounter network of more than 3 million websites) NetMarketShare Screen Resolutions (marketshare.hitslink.com) (a web analytics consulting firm, they get data from browsers of site visitors to their on-demand network of live stats customers. The data is compiled from approximately 160 million visitors per month) Display Resolution Summary: There is a bit of variation between the above sources but in general as of Jan 2011 looks like 1024x768 is about 20%, while ~85% have a higher resolution of at least 1280x768 (1280x800 is the most common of these with 15-20% of total web, depending on the source; 1280x1024 and 1366x768 follow behind with 9-14% of the share). My guess would be that the higher resolution values will be even more common if we filter on North America, and even higher if we filter on N.American corporate users (unfortunately I couldn't find any free geographically filtered statistics). Another point to note is that the 1024x768 desktop user population is likely lower than the aforementioned 20%, seeing as the iPad (1024x768 native display) is likely propping up those number. My recommendation would be to optimize around the 1280x768 constraint (*note: 1280x768 is actually a relatively rare resolution, but I think it's a valid constraint range considering that 1366x768 is relatively common and 1280 is the most common horizontal resolution). Browser + OS Constraints: To further add to the constraints we have to subtract the space taken up by the browser (assuming IE, which is the most space consuming) and the OS (assuming WinXP-Win7): Win7 has the biggest taskbar footprint at a height of 40px (XP's and Vista's is 30px) The default IE8 view uses up 25px at the bottom of the screen with the status bar and a further 120px at the top of the screen with the windows title bar and the browser UI (assuming the default 'favorites' toolbar is present, it would instead be 91px without the favorites toolbar). Assuming no scrollbar, we also loose a total of 4px horizontally for the window outline. This means that we are left with 583px of vertical space and 1276px of horizontal. In other words, a Web Safe Area of 1276 x 583 Is this a correct line of thinking? I tried to Google some design best practices but most still talk about designing around 1024x768 which seems to be quickly disappearing. Any help on this would be greatly appreciated! Thanks.

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• Calling a static method on a generic type parameter

  - by Remi Despres-Smyth

  I was hoping to do something like this, but it appears to be illegal in C#: public Collection MethodThatFetchesSomething<T>() where T : SomeBaseClass { return T.StaticMethodOnSomeBaseClassThatReturnsCollection(); } I get a compile-time error: "'T' is a 'type parameter', which is not valid in the given context." Given a generic type parameter, how can I call a static method on the generic class? The static method has to be available, given the constraint.

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• Can LINQ-to-SQL omit unspecified columns on insert so a database default value is used?

  - by Todd Ropog

  I have a non-nullable database column which has a default value set. When inserting a row, sometimes a value is specified for the column, sometimes one is not. This works fine in TSQL when the column is omitted. For example, given the following table: CREATE TABLE [dbo].[Table1]( [id] [int] IDENTITY(1,1) NOT NULL, [col1] [nvarchar](50) NOT NULL, [col2] [nvarchar](50) NULL, CONSTRAINT [PK_Table1] PRIMARY KEY CLUSTERED ([id] ASC) ) GO ALTER TABLE [dbo].[Table1] ADD CONSTRAINT [DF_Table1_col1] DEFAULT ('DB default') FOR [col1] The following two statements will work: INSERT INTO Table1 (col1, col2) VALUES ('test value', '') INSERT INTO Table1 (col2) VALUES ('') In the second statement, the default value is used for col1. The problem I have is when using LINQ-to-SQL (L2S) with a table like this. I want to produce the same behavior, but I can't figure out how to make L2S do that. I want to be able to run the following code and have the first row get the value I specify and the second row get the default value from the database: var context = new DataClasses1DataContext(); var row1 = new Table1 { col1 = "test value", col2 = "" }; context.Table1s.InsertOnSubmit(row1); context.SubmitChanges(); var row2 = new Table1 { col2 = "" }; context.Table1s.InsertOnSubmit(row2); context.SubmitChanges(); If the Auto Generated Value property of col1 is False, the first row is created as desired, but the second row fails with a null error on col1. If Auto Generated Value is True, both rows are created with the default value from the database. I've tried various combinations of Auto Generated Value, Auto-Sync and Nullable, but nothing I've tried gives the behavior I want. L2S does not omit the column from the insert statement when no value is specified. Instead it does something like this: INSERT INTO Table1 (col1, col2) VALUES (null, '') ...which of course causes a null error on col1. Is there some way to get L2S to omit a column from the insert statement if no value is given? Or is there some other way to get the behavior I want? I need the default value at the database level because not all row inserts are done via L2S, and in some cases the default value is a little more complex than a hard coded value (e.g. creating the default based on another field) so I'd rather avoid duplicating that logic.

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• How to change the probability distribution of SystemVerilog random variables?

  - by krupan

  This is for SystemVerilog. I know you can specify weights for values, or ranges of values, in the set of values that a random variable chooses from, but what if you want a nice Gaussian distribution? How do you write that kind of constraint?

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• Will this force a reinitialize in Merge Replication Topology?

  - by Refracted Paladin

  I need to add a couple of columns to a table that is a part of a replication set. It is not a constraint coulumn or a part of any article filters and it allows NULL. I have a pretty good idea that I can run this -- ALTER TABLE tblPlanDomain ADD ReportWageES VARCHAR (100) NULL and NOT force all my clients to reinitialize but I was hoping for some reassurance. Can anyone verify this one way or the other for me? Thanks,

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• How to get first derivative function for multiple dimensions

  - by nancy

  Hi If I have a constraint with a slope function f(h) = 1, h is the unknown value. I am trying to get the first derivative function for multiple dimensions. Please help. Thanks Nancy

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• Adding miliseconds to a datetime in tsql INSERT INTO

  - by DavRob60

  I'm doing a INSERT INTO query in order to initialize a new table. The primary key is RFQ_ID and Action_Time How could add 1 milisecond to each Action_Time on new record in order to avoid "Violation of PRIMARY KEY constraint" INSERT INTO QSW_RFQ_Log (RFQ_ID, Action_Time, Quote_ID) SELECT RFQ_ID , GETDATE() AS Action_Time , Quote_ID , 'Added to RFQ on Initialization' AS Note FROM QSW_Quote

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• How to optimize this mysql query - explain output included

  - by Sandeepan Nath

  This is the query (a search query basically, based on tags):- select SUM(DISTINCT(ttagrels.id_tag in (2105,2120,2151,2026,2046) )) as key_1_total_matches, td.*, u.* from Tutors_Tag_Relations AS ttagrels Join Tutor_Details AS td ON td.id_tutor = ttagrels.id_tutor JOIN Users as u on u.id_user = td.id_user where (ttagrels.id_tag in (2105,2120,2151,2026,2046)) group by td.id_tutor HAVING key_1_total_matches = 1 And following is the database dump needed to execute this query:- CREATE TABLE IF NOT EXISTS `Users` ( `id_user` int(10) unsigned NOT NULL auto_increment, `id_group` int(11) NOT NULL default '0', PRIMARY KEY (`id_user`), KEY `Users_FKIndex1` (`id_group`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=730 ; INSERT INTO `Users` (`id_user`, `id_group`) VALUES (303, 1); CREATE TABLE IF NOT EXISTS `Tutor_Details` ( `id_tutor` int(10) unsigned NOT NULL auto_increment, `id_user` int(10) NOT NULL default '0', PRIMARY KEY (`id_tutor`), KEY `Users_FKIndex1` (`id_user`), KEY `id_user` (`id_user`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=58 ; INSERT INTO `Tutor_Details` (`id_tutor`, `id_user`) VALUES (26, 303); CREATE TABLE IF NOT EXISTS `Tags` ( `id_tag` int(10) unsigned NOT NULL auto_increment, `tag` varchar(255) default NULL, PRIMARY KEY (`id_tag`), UNIQUE KEY `tag` (`tag`), KEY `id_tag` (`id_tag`), KEY `tag_2` (`tag`), KEY `tag_3` (`tag`), KEY `tag_4` (`tag`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=2957 ; INSERT INTO `Tags` (`id_tag`, `tag`) VALUES (2026, 'Brendan.\nIn'), (2046, 'Brendan.'), (2105, 'Brendan'), (2120, 'Brendan''s'), (2151, 'Brendan)'); CREATE TABLE IF NOT EXISTS `Tutors_Tag_Relations` ( `id_tag` int(10) unsigned NOT NULL default '0', `id_tutor` int(10) unsigned default NULL, `tutor_field` varchar(255) default NULL, `cdate` timestamp NOT NULL default CURRENT_TIMESTAMP, `udate` timestamp NULL default NULL, KEY `Tutors_Tag_Relations` (`id_tag`), KEY `id_tutor` (`id_tutor`), KEY `id_tag` (`id_tag`), KEY `id_tutor_2` (`id_tutor`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; INSERT INTO `Tutors_Tag_Relations` (`id_tag`, `id_tutor`, `tutor_field`, `cdate`, `udate`) VALUES (2105, 26, 'firstname', '2010-06-17 17:08:45', NULL); ALTER TABLE `Tutors_Tag_Relations` ADD CONSTRAINT `Tutors_Tag_Relations_ibfk_2` FOREIGN KEY (`id_tutor`) REFERENCES `Tutor_Details` (`id_tutor`) ON DELETE NO ACTION ON UPDATE NO ACTION, ADD CONSTRAINT `Tutors_Tag_Relations_ibfk_1` FOREIGN KEY (`id_tag`) REFERENCES `Tags` (`id_tag`) ON DELETE NO ACTION ON UPDATE NO ACTION; What the query does? This query actually searches tutors which contain "Brendan"(as their name or biography or something). The id_tags 2105,2120,2151,2026,2046 are nothing but the tags which are LIKE "%Brendan%". My question is :- 1.In the explain of this query, the reference column shows NULL for ttagrels, but there are possible keys (Tutors_Tag_Relations,id_tutor,id_tag,id_tutor_2). So, why is no key being taken. How to make the query take references. Is it possible at all? 2. The other two tables td and u are using references. Any indexing needed in those? I think not. Check the explain query output here http://www.test.examvillage.com/explain.png

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• Putting update logic in your migrations

  - by Daniel Abrahamsson

  A couple of times I've been in the situation where I've wanted to refactor the design of some model and have ended up putting update logic in migrations. However, as far as I've understood, this is not good practice (especially since you are encouraged to use your schema file for deployment, and not your migrations). How do you deal with these kind of problems? To clearify what I mean, say I have a User model. Since I thought there would only be two kinds of users, namely a "normal" user and an administrator, I chose to use a simple boolean field telling whether the user was an adminstrator or not. However, after I while I figured I needed some third kind of user, perhaps a moderator or something similar. In this case I add a UserType model (and the corresponding migration), and a second migration for removing the "admin" flag from the user table. And here comes the problem. In the "add_user_type_to_users" migration I have to map the admin flag value to a user type. Additionally, in order to do this, the user types have to exist, meaning I can not use the seeds file, but rather create the user types in the migration (also considered bad practice). Here comes some fictional code representing the situation: class CreateUserTypes < ActiveRecord::Migration def self.up create_table :user_types do |t| t.string :name, :nil => false, :unique => true end #Create basic types (can not put in seed, because of future migration dependency) UserType.create!(:name => "BASIC") UserType.create!(:name => "MODERATOR") UserType.create!(:name => "ADMINISTRATOR") end def self.down drop_table :user_types end end class AddTypeIdToUsers < ActiveRecord::Migration def self.up add_column :users, :type_id, :integer #Determine type via the admin flag basic = UserType.find_by_name("BASIC") admin = UserType.find_by_name("ADMINISTRATOR") User.all.each {|u| u.update_attribute(:type_id, (u.admin?) ? admin.id : basic.id)} #Remove the admin flag remove_column :users, :admin #Add foreign key execute "alter table users add constraint fk_user_type_id foreign key (type_id) references user_types (id)" end def self.down #Re-add the admin flag add_column :users, :admin, :boolean, :default => false #Reset the admin flag (this is the problematic update code) admin = UserType.find_by_name("ADMINISTRATOR") execute "update users set admin=true where type_id=#{admin.id}" #Remove foreign key constraint execute "alter table users drop foreign key fk_user_type_id" #Drop the type_id column remove_column :users, :type_id end end As you can see there are two problematic parts. First the row creation part in the first model, which is necessary if I would like to run all migrations in a row, then the "update" part in the second migration that maps the "admin" column to the "type_id" column. Any advice?

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• Delegates and ParamArray - Workaround Suggestions?

  - by M.A. Hanin

  Some predefined methods contain a ParamArray in their signature. Delegates, however, cannot contain a ParamArray in their signature. Main question: Assume you wish to create a delegation mechanism for a specific method which requires a ParamArray. How would you work around this constraint? "Bonus" question: Assume you wish to create a generalized delegation mechanism for all methods which require ParamArray, how would you do that?

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• Grails - attempting to include HTPPBuilder - Linkage error

  - by Stefan Kendall

  When I run grails install-dependency, I get this. java.lang.LinkageError: loader constraint violation: loader (instance of <bootloader>) previously initiated loading for a different type with name "org/xml/sax/SAXParseException" What's wrong? I've not used grails dependency management before, and this is rather cryptic. repositories { grailsPlugins() grailsHome() mavenLocal() mavenCentral() } dependencies { runtime 'org.codehaus.groovy.modules.http-builder:http-builder:0.5.0' }

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• scala for yield setting a value

  - by coubeatczech

  Hi, I want to create a list of GridBagPanel.Constraints. I read it in the scala programming book, that there is a cool for-yield construction, but I probably haven't understood the way it works correctly, because my code doesn't compile. Here it is: val d = for { i <- 0 until 4 j <- 0 until 4 } yield { c = new Constraints c.gridx = j c.gridy = i } I want to generate a List[Constraints] and for every constraint set different x,y values so later, when I later add the components, they're going to be in a grid.

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• Reduce Multiple Errors logging in sysssislog

  - by Akshay

  Need help. I am trying to automate error notifications to be sent in mailers. For that I am querying the sysssislog table. I have pasted an "Execute SQl task" on the package event handler "On error". For testing purpose, I am deliberately trying to load duplicate keys in a table which consists of a Primary key column(so as to get an error). But instead of having just one error, "Violation of primary key constraint", SSIS records 3 in the table. PFA the screenshot as well. How can i restrict the tool to log only one error and not multiple ??? Package Structure. Package ("On error Event handler") - DFT - Oledb Source - Oledb Destination SSIS Error Code DTS_E_OLEDBERROR. An OLE DB error has occurred. Error code: 0x80004005. An OLE DB record is available. Source: "Microsoft SQL Server Native Client 10.0" Hresult: 0x80004005 Description: "The statement has been terminated.". An OLE DB record is available. Source: "Microsoft SQL Server Native Client 10.0" Hresult: 0x80004005 Description: "Violation of PRIMARY KEY constraint 'PK_SalesPerson_SalesPersonID'. Cannot insert duplicate key in object 'dbo.SalesPerson'.". SSIS Error Code DTS_E_INDUCEDTRANSFORMFAILUREONERROR. The "input "OLE DB Destination Input" (56)" failed because error code 0xC020907B occurred, and the error row disposition on "input "OLE DB Destination Input" (56)" specifies failure on error. An error occurred on the specified object of the specified component. There may be error messages posted before this with more information about the failure. SSIS Error Code DTS_E_PROCESSINPUTFAILED. The ProcessInput method on component "OLE DB Destination" (43) failed with error code 0xC0209029 while processing input "OLE DB Destination Input" (56). The identified component returned an error from the ProcessInput method. The error is specific to the component, but the error is fatal and will cause the Data Flow task to stop running. There may be error messages posted before this with more information about the failure. Please guide me. Your help is very much appreciated. Thanks

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• Primary Key Names in Fluent Nhibernate

  - by fregas

  Is there a way in fluent nhibernate (or possibly NHibernate in general) to tell it to generate the primary keys differently? It creates the column name for the key fine, but the index/constraint gets weird generated names like: PK_Address_3214EC2725332734 PK_CreditCa_3214EC2756CA82C8 etc... I can use straight sql to rename them but i'd rather not. thanks, all

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• Symfony2 bindrequest error

  - by user1321109

  namespace Topxia\LiftBundle\Form; use Symfony\Component\Validator\Constraint as Assert; class AddUser { /** * @Assert\NotBlank(message="???????") */ public $username; /** * @Assert\NotBlank(message="????????") */ public $name; /** * @Assert\NotBlank(message="??????") * @Assert\MinLength(limit=4,message="?????") * @Assert\MaxLength(limit=24,message="?????") */ public $password; /** * @Assert\NotBlank(message="??????") */ public $rpassword; /** * @Assert\NotBlank(message="???????") * @Assert\Email(message="???????") */ public $email; /** * @Assert\NotBlank(message="k3????????") */ public $num; /** * @Assert\NotBlank() * @Assert\Choice({"0", "1", "2", "3", "4"}) */ public $roles; public $changePassword; } namespace Topxia\LiftBundle\Form; use Symfony\Component\Form\AbstractType; use Symfony\Component\Form\FormBuilder; class AddUserType extends AbstractType{ public function buildForm(FormBuilder $builder, array $options){ $builder->add('username', 'text', array('label' => '????')); $builder->add('name', 'text', array('label' => '???')); $builder->add('password', 'password', array('label' => '??')); $builder->add('rpassword', 'password', array('label' => '????')); $builder->add('email', 'email', array('label' => '??')); $builder->add('num', 'text', array('label' => 'K3????')); $builder->add('roles', 'choice', array('label' => '???', 'multiple' => false, 'expanded' => true, 'choices' => array( '0' => '?????', '1' => '?????', '2' => '?????', '3' => '???', '4' => '???' ), )); $builder->add('changePassword', 'checkbox', array('label' => '??????', 'value' => '1')); } public function getName(){ return 'add_user'; } } when i use $form-bindRequest($request); in conctollor there is an error : [Semantical Error] The annotation "@Symfony\Component\Validator\Constraint\NotBlank" in property Topxia\LiftBundle\Form\AddUser::$username does not exist, or could not be auto-loaded. 500 Internal Server Error - AnnotationException I have no idea about this. Thanks

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• JPA - How to truncate tables between unit tests

  - by Theo

  I want to cleanup the database after every test case without rolling back the transaction. I have tried DBUnit's DatabaseOperation.DELETE_ALL, but it does not work if a deletion violates a foreign key constraint. I know that I can disable foreign key checks, but that would also disable the checks for the tests (which I want to prevent). I'm using JUnit 4, JPA 2.0 (Eclipselink), and Derby's in-memory database. Any ideas? Thanks, Theo

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• Why would I get a duplicate key error when updating a row?

  - by hdx

  I'm using postgres and I'm getting the duplicate key error when updating a row: cursor.execute("UPDATE jiveuser SET userenabled = 0 WHERE userid = %s" % str(userId)) psycopg2.IntegrityError: duplicate key value violates unique constraint "jiveuser_pk" I don't understand how updating a row can cause this error... any help will be much appreciated.

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• Determine if the document is DOC or DOCX in Java app without knowing its extension

  - by Andriy

  There is a constraint in the content management system that requires to store all word documents with specific extension (different from DOC or DOCX). However, when outputting the document to user we need to know if it is a DOC or DOCX file in order to provide the right MIME type. So, is there a way to programatically find out if document is DOC or DOCX by its content?

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• CHECK/NOCHECK for Sql Compact Edition

  - by Ryan H

  I am attempting to wipe and repopulate test data on SQL CE. I am getting an error due to FK constraints existing. Typically in Sql2005 I would ALTER TABLE [tablename] CHECK/NOCHECK CONSTRAINT ALL to enable/disable all constraints. From what I could find in my searching, it seems that this might not be supported in CE. Is that true? If so, is there an alternative?

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• Handling national language prefix for checkconstraints

  - by Chris Chilvers

  I'm trying to create a check constraint such as CHECK Type IN (N'Create', N'Remove') for an enumeration's value. Sqlite complains about this syntax and only accepts CHECK Type IN ('Create', 'Remove'). The main database will be Sql Server 2005, but I use sqlite's in memory database for unit tests. Is there any way to get sqlite to recognise the national language (N) prefix? Alternatively, is there an easy way when using FluentNHibernate to adapt an nvarchar constant to match the database's dialect?

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