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  • JPA 2 and Hibernate 3.5.1 MEMBER OF query doesnt work.

    - by Ed_Zero
    I'm trying the following JPQL and it fails misserably: Query query = em.createQuery("SELECT u FROM User u WHERE 'admin' MEMBER OF u.roles"); List users = query.query.getResultList(); I get the following exception: ERROR [main] PARSER.error(454) | <AST>:0:0: unexpected end of subtree java.lang.IllegalArgumentException: org.hibernate.hql.ast.QuerySyntaxException: unexpected end of subtree [SELECT u FROM com.online.data.User u WHERE 'admin' MEMBER OF u.roles] ERROR [main] PARSER.error(454) | <AST>:0:0: expecting "from", found '<ASTNULL>' ... ... Caused by: org.hibernate.hql.ast.QuerySyntaxException: unexpected end of subtree [SELECT u FROM com.online.data.User u WHERE 'admin' MEMBER OF u.roles] I have Spring 3.0.1.RELEASE, Hibernate 3.5.1-Final and maven to glue dependencies. User class: @Entity public class User { @Id @Column(name = "USER_ID") @GeneratedValue(strategy = GenerationType.IDENTITY) private long id; @Column(unique = true, nullable = false) private String username; private boolean enabled; @ElementCollection private Set<String> roles = new HashSet<String>(); ... } Spring configuration: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:p="http://www.springframework.org/schema/p" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/tx/spring-context-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd"> <!-- Reading annotation driven configuration --> <tx:annotation-driven transaction-manager="transactionManager" /> <bean class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" /> <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" /> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="${jdbc.driverClassName}" /> <property name="url" value="${jdbc.url}" /> <property name="username" value="${jdbc.username}" /> <property name="password" value="${jdbc.password}" /> <property name="maxActive" value="100" /> <property name="maxWait" value="1000" /> <property name="poolPreparedStatements" value="true" /> <property name="defaultAutoCommit" value="true" /> </bean> <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"> <property name="entityManagerFactory" ref="entityManagerFactory" /> <property name="dataSource" ref="dataSource" /> </bean> <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="jpaVendorAdapter"> <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> <property name="showSql" value="true" /> <property name="databasePlatform" value="${hibernate.dialect}" /> </bean> </property> <property name="loadTimeWeaver"> <bean class="org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver" /> </property> <property name="jpaProperties"> <props> <prop key="hibernate.hbm2ddl.auto">update</prop> <prop key="hibernate.current_session_context_class">thread</prop> <prop key="hibernate.cache.provider_class">org.hibernate.cache.NoCacheProvider</prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.format_sql">false</prop> <prop key="hibernate.show_comments">true</prop> </props> </property> <property name="persistenceUnitName" value="punit" /> </bean> <bean id="JpaTemplate" class="org.springframework.orm.jpa.JpaTemplate"> <property name="entityManagerFactory" ref="entityManagerFactory" /> </bean> </beans> Persistence.xml <?xml version="1.0" encoding="UTF-8"?> <persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence"> <persistence-unit name="punit" transaction-type="RESOURCE_LOCAL" /> </persistence> pom.xml maven dependencies. <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate</artifactId> <version>${hibernate.version}</version> <type>pom</type> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>${hibernate.version}</version> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-annotations</artifactId> <version>${hibernate.version}</version> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-entitymanager</artifactId> <version>${hibernate.version}</version> </dependency> <dependency> <groupId>commons-dbcp</groupId> <artifactId>commons-dbcp</artifactId> <version>1.2.2</version> <type>jar</type> </dependency> <dependency> <groupId>org.springframework.security</groupId> <artifactId>spring-security-web</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework.security</groupId> <artifactId>spring-security-config</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework.security</groupId> <artifactId>spring-security-taglibs</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework.security</groupId> <artifactId>spring-security-acl</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>javax.annotation</groupId> <artifactId>jsr250-api</artifactId> <version>1.0</version> </dependency> <properties> <!-- Application settings --> <spring.version>3.0.1.RELEASE</spring.version> <hibernate.version>3.5.1-Final</hibernate.version> Im running a unit test to check the configuration and I am able to run other JPQL queries the only ones that I am unable to run are the IS EMPTY, MEMBER OF conditions. The complete unit test is as follows: TestIntegration @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(locations = { "/spring/dataLayer.xml"}) @Transactional @TransactionConfiguration public class TestUserDaoImplIntegration { @PersistenceContext private EntityManager em; @Test public void shouldTest() throws Exception { try { //WORKS Query query = em.createQuery("SELECT u FROM User u WHERE 'admin' in elements(u.roles)"); List users = query.query.getResultList(); //DOES NOT WORK } catch (Exception e) { e.printStackTrace(); throw e; } try { Query query = em.createQuery("SELECT u FROM User u WHERE 'admin' MEMBER OF u.roles"); List users = query.query.getResultList(); } catch (Exception e) { e.printStackTrace(); throw e; } } }

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  • How to grey out spinner in Android?

    - by Janusz
    I use two Spinner in my App. One of them is initially disabled because I need the user to select something in the first spinner to load the content of the second one. I would like to change the design of the second spinner to show the user that the spinner is not active, eg. grey the spinner out. How can I achieve this? If this is not possible how would you change this dialog to make it clear to the user that she has to select something in the first spinner?

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  • How to do a timestamp comparison with JPA query?

    - by Robert
    We need to make sure only results within the last 30 days are returned for a JPQL query. An example follows: Date now = new Date(); Timestamp thirtyDaysAgo = new Timestamp(now.getTime() - 86400000*30); Query query = em.createQuery( "SELECT msg FROM Message msg "+ "WHERE msg.targetTime < CURRENT_TIMESTAMP AND msg.targetTime > {ts, '"+thirtyDaysAgo+"'}"); List result = query.getResultList(); Here is the error we receive: <openjpa-1.2.3-SNAPSHOT-r422266:907835 nonfatal user error org.apache.openjpa.persistence.ArgumentException: An error occurred while parsing the query filter 'SELECT msg FROM BroadcastMessage msg WHERE msg.targetTime < CURRENT_TIMESTAMP AND msg.targetTime {ts, '2010-04-18 04:15:37.827'}'. Error message: org.apache.openjpa.kernel.jpql.TokenMgrError: Lexical error at line 1, column 217. Encountered: "{" (123), after : "" Help!

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  • Offer the posibility to preview a personalized product

    - by bellesebastien
    I want to give my client's the possibility to preview their personalized product. In a nutshell, personalization means the user specifies some text and positions the text somewhere on an image of the product. A great example of what I'd like to achieve is this. Select a frame size and then hit Personalize, after you select the occasion and add the text you can chose to preview the product. The hardest thing to do here, as I see it, is to generate the image. The positioning of text will probably be made in javascript. Do you have any recommendations? Just as a note, using scene7 is not a possibility. Thanks.

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  • Extjs: Tree, Selecting node after creating the tree

    - by Natkeeran
    I have a simple TreePanel. I would like to select a particular node upon loading it. The nodes are from a remote file (json). The tree is loading as expected. However, the node is not being selected. Firebug shows node as undefined. This perhaps because of the async property. But, I an unable to configure this other wise, or specify the node be selected. Any suggestions welcomed, and thank you. LeftMenuTree = new Ext.tree.TreePanel({ renderTo: 'TreeMenu', collapsible: false, height: 450, border: false, userArrows: true, animate: true, autoScroll: true, id: 'testtest', dataUrl: fileName, root: { nodeType: 'async', iconCls:'home-icon', expanded:true, text: rootText }, listeners: { "click": { fn: onPoseClick, scope: this } }, "afterrender": { fn: setNode, scope: this } }); function setNode(){ alert (SelectedNode); if (SelectedNode == "Orders"){ var treepanel = Ext.getCmp('testtest'); var node = treepanel.getNodeById("PendingItems"); node.select(); } }

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  • Comparing Dates in LINQ and C#

    - by Redburn
    I have a LINQ query which checks to see if there are any tests done since the beginning of the year. var MetersTestedCount = (from n in _mttDomainContext.MTTMeterTests where n.TestDate > DateTime.Parse("1/1/2010") select n.TestDate).Count(); This query however returns an empty set. I have a similar SQL query which pulls some records, USE MeterTestTracking Select * From MTTMeterTest WHERE TestDate > '1/1/2010' I have been to the previous posts. Even though similar, still no help: How to compare just the date, not the timestamp using LINQ and How to compare dates in LINQ? What's the correct way to check dates in LINQ to return a dataset?

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  • Oracle sql: using bind variable for dates..

    - by user333747
    Here is a simple working query without bind variables: select * from table1 where time_stamp sysdate - INTERVAL '1' day; where time_stamp is of type DATE. I should be able to input any number of days in the above query using bind variable. So I tried the following and does not seem to work: select * from table1 where time_stamp sysdate - INTERVAL :days day; I tried entering the numeric input both as 10 and '10',for eg. You get ORA-00933 error on 10g.

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  • Not your usual "The multi-part identifier could not be bound" error

    - by Eugene Niemand
    I have the following query, now the strange thing is if I run this query on my development and pre-prod server it runs fine. If I run it on production it fails. I have figured out that if I run just the Select statement its happy but as soon as I try insert into the table variable it complains. DECLARE @RESULTS TABLE ( [Parent] VARCHAR(255) ,[client] VARCHAR(255) ,[ComponentName] VARCHAR(255) ,[DealName] VARCHAR(255) ,[Purchase Date] DATETIME ,[Start Date] DATETIME ,[End Date] DATETIME ,[Value] INT ,[Currency] VARCHAR(255) ,[Brand] VARCHAR(255) ,[Business Unit] VARCHAR(255) ,[Region] VARCHAR(255) ,[DealID] INT ) INSERT INTO @RESULTS SELECT DISTINCT ClientName 'Parent' ,F.ClientID 'client' ,ComponentName ,A.DealName ,CONVERT(SMALLDATETIME , ISNULL(PurchaseDate , '1900-01-01')) 'Purchase Date' ,CONVERT(SMALLDATETIME , ISNULL(StartDate , '1900-01-01')) 'Start Date' ,CONVERT(SMALLDATETIME , ISNULL(EndDate , '1900-01-01')) 'End Date' ,DealValue 'Value' ,D.Currency 'Currency' ,ShortBrand 'Brand' ,G.BU 'Business Unit' ,C.DMRegion 'Region' ,DealID FROM LTCDB_admin_tbl_Deals A INNER JOIN dbo_DM_Brand B ON A.BrandID = B.ID INNER JOIN LTCDB_admin_tbl_DM_Region C ON A.Region = C.ID INNER JOIN LTCDB_admin_tbl_Currency D ON A.Currency = D.ID INNER JOIN LTCDB_admin_tbl_Deal_Clients E ON A.DealID = E.Deal_ID INNER JOIN LTCDB_admin_tbl_Clients F ON E.Client_ID = F.ClientID INNER JOIN LTCDB_admin_tbl_DM_BU G ON G.ID = A.BU INNER JOIN LTCDB_admin_tbl_Deal_Components H ON A.DealID = H.Deal_ID INNER JOIN LTCDB_admin_tbl_Components I ON I.ComponentID = H.Component_ID WHERE EndDate != '1899-12-30T00:00:00.000' AND StartDate < EndDate AND B.ID IN ( 1 , 2 , 5 , 6 , 7 , 8 , 10 , 12 ) AND C.SalesRegionID IN ( 1 , 3 , 4 , 11 , 16 ) AND A.BU IN ( 1 , 2 , 3 , 4 , 5 , 6 , 8 , 9 , 11 , 12 , 15 , 16 , 19 , 20 , 22 , 23 , 24 , 26 , 28 , 30 ) AND ClientID = 16128 SELECT ... FROM @Results I get the following error Msg 8180, Level 16, State 1, Line 1 Statement(s) could not be prepared. Msg 4104, Level 16, State 1, Line 1 The multi-part identifier "Tbl1021.ComponentName" could not be bound. Msg 4104, Level 16, State 1, Line 1 The multi-part identifier "Tbl1011.Currency" could not be bound. Msg 207, Level 16, State 1, Line 1 Invalid column name 'Col2454'. Msg 207, Level 16, State 1, Line 1 Invalid column name 'Col2461'. Msg 207, Level 16, State 1, Line 1 Invalid column name 'Col2491'. Msg 207, Level 16, State 1, Line 1 Invalid column name 'Col2490'. Msg 207, Level 16, State 1, Line 1 Invalid column name 'Col2482'. Msg 207, Level 16, State 1, Line 1 Invalid column name 'Col2478'. Msg 207, Level 16, State 1, Line 1 Invalid column name 'Col2477'. Msg 207, Level 16, State 1, Line 1 Invalid column name 'Col2475'. EDIT - EDIT - EDIT - EDIT - EDIT - EDIT through a process of elimination I have found that following and wondered if anyone can shed some light on this. If I remove only the DISTINCT the query runs fine, add the DISTINCT and I get strange errors. Also I have found that if I comment the following lines then the query runs with the DISTINCT what is strange is that none of the columns in the table LTCDB_admin_tbl_Deal_Components is referenced so I don't see how the distinct will affect that. INNER JOIN LTCDB_admin_tbl_Deal_Components H ON A.DealID = H.Deal_ID

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  • Grails GORM (Hibernate) query

    - by bsreekanth
    Hello, I'm trying to do the below sql statement in GORM select * from table1 where table1.x not in (select x from table 2 where y='something'); so, I have two tables, and needs to find the entries from table 1 which are not in table 2. In Grails def xx= table2.findByY('something') def c = table1.createCriteria() def result= c.list { not ( in('x', xx) ) } the syntax is wrong, and I'm not sure how to simulate not in sql logic. As a learning point, if someone can also tell me why minus (-) operator in grails/groovy doesn't work with list. I tried getting x and y seperately, and doing x.minus(y), but it doesn't change the list. I saw an explanation at http://stackoverflow.com/questions/1754576/groovy-on-grails-list-not-working , but I would expect the list defined are local. thank you so much.

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  • Replication Services in a BI environment

    - by jorg
    In this blog post I will explain the principles of SQL Server Replication Services without too much detail and I will take a look on the BI capabilities that Replication Services could offer in my opinion. SQL Server Replication Services provides tools to copy and distribute database objects from one database system to another and maintain consistency afterwards. These tools basically copy or synchronize data with little or no transformations, they do not offer capabilities to transform data or apply business rules, like ETL tools do. The only “transformations” Replication Services offers is to filter records or columns out of your data set. You can achieve this by selecting the desired columns of a table and/or by using WHERE statements like this: SELECT <published_columns> FROM [Table] WHERE [DateTime] >= getdate() - 60 There are three types of replication: Transactional Replication This type replicates data on a transactional level. The Log Reader Agent reads directly on the transaction log of the source database (Publisher) and clones the transactions to the Distribution Database (Distributor), this database acts as a queue for the destination database (Subscriber). Next, the Distribution Agent moves the cloned transactions that are stored in the Distribution Database to the Subscriber. The Distribution Agent can either run at scheduled intervals or continuously which offers near real-time replication of data! So for example when a user executes an UPDATE statement on one or multiple records in the publisher database, this transaction (not the data itself) is copied to the distribution database and is then also executed on the subscriber. When the Distribution Agent is set to run continuously this process runs all the time and transactions on the publisher are replicated in small batches (near real-time), when it runs on scheduled intervals it executes larger batches of transactions, but the idea is the same. Snapshot Replication This type of replication makes an initial copy of database objects that need to be replicated, this includes the schemas and the data itself. All types of replication must start with a snapshot of the database objects from the Publisher to initialize the Subscriber. Transactional replication need an initial snapshot of the replicated publisher tables/objects to run its cloned transactions on and maintain consistency. The Snapshot Agent copies the schemas of the tables that will be replicated to files that will be stored in the Snapshot Folder which is a normal folder on the file system. When all the schemas are ready, the data itself will be copied from the Publisher to the snapshot folder. The snapshot is generated as a set of bulk copy program (BCP) files. Next, the Distribution Agent moves the snapshot to the Subscriber, if necessary it applies schema changes first and copies the data itself afterwards. The application of schema changes to the Subscriber is a nice feature, when you change the schema of the Publisher with, for example, an ALTER TABLE statement, that change is propagated by default to the Subscriber(s). Merge Replication Merge replication is typically used in server-to-client environments, for example when subscribers need to receive data, make changes offline, and later synchronize changes with the Publisher and other Subscribers, like with mobile devices that need to synchronize one in a while. Because I don’t really see BI capabilities here, I will not explain this type of replication any further. Replication Services in a BI environment Transactional Replication can be very useful in BI environments. In my opinion you never want to see users to run custom (SSRS) reports or PowerPivot solutions directly on your production database, it can slow down the system and can cause deadlocks in the database which can cause errors. Transactional Replication can offer a read-only, near real-time database for reporting purposes with minimal overhead on the source system. Snapshot Replication can also be useful in BI environments, if you don’t need a near real-time copy of the database, you can choose to use this form of replication. Next to an alternative for Transactional Replication it can be used to stage data so it can be transformed and moved into the data warehousing environment afterwards. In many solutions I have seen developers create multiple SSIS packages that simply copies data from one or more source systems to a staging database that figures as source for the ETL process. The creation of these packages takes a lot of (boring) time, while Replication Services can do the same in minutes. It is possible to filter out columns and/or records and it can even apply schema changes automatically so I think it offers enough features here. I don’t know how the performance will be and if it really works as good for this purpose as I expect, but I want to try this out soon!

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  • C# LINQ Oracle date Functions

    - by user1079925
    I am trying to generate a sql statement to be used in Oracle11g, using linq. The problem arises when using dates: The SQL generated by linq gives SELECT * FROM <table> WHERE start_date > '24/11/2012 00:00:00' and end_date < '28/11/2012 00:00:00' This causes an oracle error: ORA-01830 - date format picture ends before converting entire input string Adding TO_DATE to the query fixes the ORA-01830, as it is converting the string to a oracle date whilst now knowing the date format. SELECT * FROM <table> WHERE start_date > TO_DATE('24/11/2012 00:00:00','DD/MM/YYYY HH24:MI:SS') and end_date < TO_DATE('28/11/2012 00:00:00','DD/MM/YYYY HH24:MI:SS') So, is there a way to add TO_DATE to LINQ (for oracle)? If not, please tell me how to work around this issue. Thanks

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  • LINQ for SQL Developers and DBA’s

    - by AtulThakor
    Firstly I’d just like to thank the guys who organise the SQL Server User Group (Martin/Tony/Chris) and for giving me the opportunity to speak at the recent event. Sorry about the slides taking so long but here they are along with some extra information. Firstly the demo’s were all done using LINQPad 4.0 which can be downloaded here: http://www.linqpad.net/ There are 2 versions 3.5/4.0 With 3.5 you should be able to replicate the problem I showed where a query using a parameter which is X characters long would create a different execution plan to a query which uses a parameter which is Y characters long, otherwise I would just use 4.0 The sample database used is AdventureWorksLT2008 which can be downloaded from here: http://msftdbprodsamples.codeplex.com/releases/view/37109 The scripts have been named so that you can select the appropriate way to run them i.e.: C# expression / C#statement, each script can be run individually be highlighting the query and clicking the play symbol or hitting F5. Scripts and Slides: http://sqlblogcasts.com/blogs/atulthakor/An%20Introduction%20to%20LINQ.zip Please don't hesitate in sending any questions via email/twitter, I’ll try my best to answer your questions! Thanks, Atul

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  • Android: Saving custom button and spinner on orientation change

    - by Jacob Huggart
    Hello All, I am new to Android programming and was handed a fairly large program that is almost complete, but needed support for switching between portrait and landscape view. I added android:configChanges="keyboardHidden|orientation" to the manifest and used onConfigurationChanged to save the view data and that works. However, there is a button that displays the date selected (when pressed a calendar to select the date comes up) and a spinner that displays the current view and is used to select a new view. Those two items are being cleared/reset and do not work at all after the screen flip. I have been attempting to use onSaveInstanceState and onRestoreInstanceState to fix that, but I cannot figure out how to get it to work. Any advice? FYI, This is how my spinner is set up: Spinner s = (Spinner) findViewById(R.id.siteSelector); ArrayAdapter<?> adapter = ArrayAdapter.createFromResource( this, R.array.sites, android.R.layout.simple_spinner_item); adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); s.setAdapter(adapter);

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  • Windows Explorer argument not being interpreted?

    - by MarceloRamires
    I'm currently using: Process.Start("explorer.exe", "/Select, " + fullPath); //with file name.extension That basically tells windows explorer to open the folder where the file is in, with the given file selected. But, by the forces of evil, sometimes it works and sometimes it just opens the file ("/select" is... ignored) Has anyone ever experienced this? If it changes anything, it's a file in a local network and the path looks like this \\server\folder\subfolder\something\file.ext (of course in c# every '\' is doubled, and @ is not a choice, the path is generated by something else) I'll be constantly reading comments to supply any aditional information

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  • Can PetaPoco populate an object using a stored procedure with a join clause?

    - by Mark Kadlec
    I have a stored procedure that does something similar to: SELECT a.TaskId, b.CompanyCode FROM task a JOIN company b ON b.CompanyId = a.CompanyId; I have an object called TaskItem that has the TaskId and CompanyCode properties, but when I execute the following (which I would have assumed worked): var masterDatabase = new Database("MasterConnectionString"); var s = PetaPoco.Sql.Builder.Append("EXEC spGetTasks @@numberOfTasks = @0", numberOfTasks); var tasks = masterDatabase.Query<Task>(s); The problem is that the CompanyCode column does not exist in the task table, I did a trace and it seems that PetaPoco is trying to select all the properties from the task table and populating using the stored procedure. How can I use PetaPoco to simply populate the list of task objects with the results of the stored procedure?

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  • Parallelism in .NET – Part 8, PLINQ’s ForAll Method

    - by Reed
    Parallel LINQ extends LINQ to Objects, and is typically very similar.  However, as I previously discussed, there are some differences.  Although the standard way to handle simple Data Parellelism is via Parallel.ForEach, it’s possible to do the same thing via PLINQ. PLINQ adds a new method unavailable in standard LINQ which provides new functionality… LINQ is designed to provide a much simpler way of handling querying, including filtering, ordering, grouping, and many other benefits.  Reading the description in LINQ to Objects on MSDN, it becomes clear that the thinking behind LINQ deals with retrieval of data.  LINQ works by adding a functional programming style on top of .NET, allowing us to express filters in terms of predicate functions, for example. PLINQ is, generally, very similar.  Typically, when using PLINQ, we write declarative statements to filter a dataset or perform an aggregation.  However, PLINQ adds one new method, which provides a very different purpose: ForAll. The ForAll method is defined on ParallelEnumerable, and will work upon any ParallelQuery<T>.  Unlike the sequence operators in LINQ and PLINQ, ForAll is intended to cause side effects.  It does not filter a collection, but rather invokes an action on each element of the collection. At first glance, this seems like a bad idea.  For example, Eric Lippert clearly explained two philosophical objections to providing an IEnumerable<T>.ForEach extension method, one of which still applies when parallelized.  The sole purpose of this method is to cause side effects, and as such, I agree that the ForAll method “violates the functional programming principles that all the other sequence operators are based upon”, in exactly the same manner an IEnumerable<T>.ForEach extension method would violate these principles.  Eric Lippert’s second reason for disliking a ForEach extension method does not necessarily apply to ForAll – replacing ForAll with a call to Parallel.ForEach has the same closure semantics, so there is no loss there. Although ForAll may have philosophical issues, there is a pragmatic reason to include this method.  Without ForAll, we would take a fairly serious performance hit in many situations.  Often, we need to perform some filtering or grouping, then perform an action using the results of our filter.  Using a standard foreach statement to perform our action would avoid this philosophical issue: // Filter our collection var filteredItems = collection.AsParallel().Where( i => i.SomePredicate() ); // Now perform an action foreach (var item in filteredItems) { // These will now run serially item.DoSomething(); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This would cause a loss in performance, since we lose any parallelism in place, and cause all of our actions to be run serially. We could easily use a Parallel.ForEach instead, which adds parallelism to the actions: // Filter our collection var filteredItems = collection.AsParallel().Where( i => i.SomePredicate() ); // Now perform an action once the filter completes Parallel.ForEach(filteredItems, item => { // These will now run in parallel item.DoSomething(); }); This is a noticeable improvement, since both our filtering and our actions run parallelized.  However, there is still a large bottleneck in place here.  The problem lies with my comment “perform an action once the filter completes”.  Here, we’re parallelizing the filter, then collecting all of the results, blocking until the filter completes.  Once the filtering of every element is completed, we then repartition the results of the filter, reschedule into multiple threads, and perform the action on each element.  By moving this into two separate statements, we potentially double our parallelization overhead, since we’re forcing the work to be partitioned and scheduled twice as many times. This is where the pragmatism comes into play.  By violating our functional principles, we gain the ability to avoid the overhead and cost of rescheduling the work: // Perform an action on the results of our filter collection .AsParallel() .Where( i => i.SomePredicate() ) .ForAll( i => i.DoSomething() ); The ability to avoid the scheduling overhead is a compelling reason to use ForAll.  This really goes back to one of the key points I discussed in data parallelism: Partition your problem in a way to place the most work possible into each task.  Here, this means leaving the statement attached to the expression, even though it causes side effects and is not standard usage for LINQ. This leads to my one guideline for using ForAll: The ForAll extension method should only be used to process the results of a parallel query, as returned by a PLINQ expression. Any other usage scenario should use Parallel.ForEach, instead.

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  • C socket programming: calling recv() changes my socket file descriptor?

    - by fourier
    Hey all, I have this strange problem with recv(). I'm programming client/server where client send() a message (a structure to be exact) and server recv() it. I am also working with multiple sockets and select(). while(1) { readset = info->read_set; info->copy_set = info->read_set; timeout.tv_sec = 1; timeout.tv_usec = 0; // 0.5 seconds ready = select(info->max_fd+1, &readset, NULL, NULL, &timeout); if (ready == -1) { printf("S: ERROR: select(): %s\nEXITING...", strerror(errno)); exit(1); } else if (ready == 0) { continue; } else { printf("S: oh finally you have contacted me!\n"); for(i = 0; i < (info->max_fd+1); i++) { if(FD_ISSET(i, &readset)) //this is where problem begins { printf("S: %i is set\n", i); printf("S: we talking about socket %i son\n", i); // i = 4 num_bytes = recv(i, &msg, MAX_MSG_BYTE, 0); printf("S: number of bytes recieved in socket %i is %i\n", i, num_bytes); // prints out i = 0 what?? if (num_bytes == 0) { printf("S: socket has been closed\n"); break; } else if (num_bytes == -1) { printf("S: ERROR recv: %d %s \n", i, strerror(errno)); continue; } else { handle_request(arg, &msg); printf("S: msg says %s\n", msg->_payload); } } // if (FD_ISSET(i, &readset) else printf("S: %i is not set\n", i); } // for (i = 0; i < maxfd+1; i++) to check sockets for msg } // if (ready == -1) info->read_set = info->copy_set; printf("S: copied\n"); } the problem I have is that in read_set, 0~3 aren't set and 4 is. That is fine. But when i call recv(), i suddently becomes 0. Why is that? It doesn't make sense to me why recv() would take an socket file descriptor number and modify to another number. Is that normal? Am I missing something? S: 0 is not set S: 1 is not set S: 2 is not set S: 3 is not set S: 4 is set S: we talking about socket 4 son S: i is strangely or unstrangely 0 S: number of bytes recieved in socket 0 is 40 That's what it prints out.

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  • How to use Enum as NamedQuery parameters in JPA

    - by n002213f
    I have an Entity with a enum attribute and a couple on NamedQueries. One of these NamedQueries has a the enum attribute as a parameter i.e. SELECT m FROM Message m WHERE status = :status When i try to ru n the query i get the following error; Caused by: java.lang.IllegalArgumentException: You have attempted to set a value of type class my.package.Status for parameter status with expected type of class my.package.Status from query string SELECT m FROM Message m WHERE m.status = :status. I'm using Toplink How is this? How would i make JPA happy?

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  • How common are "bandage" fixes?

    - by gablin
    Imagine the following scenario: You've detected that your (or someone else's) program has a bug - a function produces the wrong result when given a particular input. You examine the code and can't find anything wrong: it just seem to bog out when given this input. You can now do one of two things: you either examine the code further until you've found the actual cause; or you slap on a bandage by adding an if statement checking if the input is this particular input - if it is, return the expected value. To me, applying the bandage would be completely unacceptable. If the code is behaving unexpectingly on this input, what other input that you've missed will it react strangely to? It just doesn't seem like a fix at all - you're just shoveling the problem under the rug. As I wouldn't even consider doing this, I'm surprised at how often the professors and books keep reminding us about how applying "bandage" fixes is not a good idea. So this makes me wonder: just how common are these kinds of "fixes"?

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  • C# ?? null coalescing operator

    - by anirudha
    the null coalescing operator is used for set the value when object is null. if object have some value that nothing change and still have their default value they have.  string str = "i am string";            string message = str ?? "it is null";   the message have same value as str variable because str not null. if str is null that message have value “it is null”; as declared in statement. coalescing operator does not work on nullable operator such as int?

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  • Android TitleBar / NavBar ?

    - by Chris
    I am not sure what the proper term is, but I am trying to add a "TitleBar" to the top of one of the windows in my App. Much like the Contacts App, I have several Tabs along the top of the screen. When you select an item from the list, it loads the next Activity, but that Activity no longer has the Tabs at the top of the screen. I don't know if it is called a TitleBar or what. The Contacts App has this TitleBar along the top of the screen when you select a person from the list of Contacts. I am trying to mimick the Grey Bar that says "George Washington"

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  • Read from multiple tables in vb.net data reader

    - by user225269
    I'm trying to read from two tables in mysql: Dim sqlcom As MySqlCommand = New MySqlCommand("Select * from mother, father where IDNO= '" & TextBox14.Text & "' ", sqlcon) -But I get this error: Column 'IDNO' in where clause is ambiguous Here is the whole code: Dim NoAcc As String Dim NoAccmod2 As String Dim NoPas As String Dim sqlcon As New MySqlConnection("Server=localhost; Database=school;Uid=root;Pwd=nitoryolai123$%^;") Dim sqlcom As MySqlCommand = New MySqlCommand("Select * from mother, father where IDNO= '" & TextBox14.Text & "' ", sqlcon) sqlcon.Open() Dim rdr As MySqlDataReader rdr = sqlcom.ExecuteReader If rdr.HasRows Then rdr.Read() NoAcc = rdr("IDNO") If (TextBox14.Text = NoAcc) Then TextBox7.Text = rdr("MOTHER") If (TextBox14.Text = NoAcc) Then TextBox8.Text = rdr("MOTHER_OCCUPATION") If (TextBox14.Text = NoAcc) Then TextBox10.Text = rdr("FATHER") If (TextBox14.Text = NoAcc) Then TextBox11.Text = rdr("FATHER_OCCUPATION") End If -Any suggestions that could help solve this problem? Or even other techniques on achieving the goal of reading data from two tables using data reader? This is a winform, not a web form

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  • jquery ui autocomplete is changing my listbox

    - by oo
    I am trying to change my comboboxes to use autocomplete so i leverage the code listed here (which worked perfectly for my dropdowns) The issue is that i also on the same page have a listbox with the following code: <%= Html.ListBox("Cars", Model.BodyParts.Select( x => new SelectListItem { Text = x.Name, Value = x.Id, Selected = Model.CarsSelected.Any(y => y.Id == x.Id) } ))%> and it appears that the jquery ui code is changing this to a autocomplete dropdown as well (as opposed to keeping it as a multi select list box) any idea how to prevent this from happening?

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  • C# DataGridViewComboBoxCell setting value manually, value not valid

    - by Jay
    Hi, here is my code: private class Person { private string myName; private int myValue; public Person(string name, int value) { myName = name; myValue = value; } public override string ToString() { return myName; } public string Name { get { return myName; } set { myName = value; } } public int Value { get { return myValue; } set { myValue = value; } } } I use it to fill a DataGridViewComboBoxCell like this: myDataGridViewComboBoxCell.ValueMember = "Value"; myDataGridViewComboBoxCell.DisplayMember = "Name"; myDataGridViewComboBoxCell.Items.Add(new Person("blabla", someNumber)); all I want to do now is to select a person: myDataGridViewComboBoxCell.Value = someNumber; but keep getting "value is not valid"-error. Any Idea why? When I select an Item in my program I can see the right Value (someNumber) so Display and ValueMember are set correctly...

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  • Panduit Delivers on the Digital Business Promise

    - by Kellsey Ruppel
    How a 60-Year-Old Company Transformed into a Modern Digital BusinessConnecting with audiences through a robust online experience across multiple channels and devices is a nonnegotiable requirement in today’s digital world. Companies need a digital platform that helps them create, manage, and integrate processes, content, analytics, and more.Panduit, a company founded nearly 60 years ago, needed to simplify and modernize its enterprise application and infrastructure to position itself for long-term growth. Learn how it transformed into a digital business using Oracle WebCenter and Oracle Business Process Management. Join this webcast for an in-depth look at how these Oracle technologies helped Panduit: Increase self-service activity on their portal by 75% Improve number and quality of sales leads through increased customer interactions and registration over the web and mobile Create multichannel self-service interactions and content-enabled business processes Register now for this webcast. Register Now Presented by:Andy KershawSenior Director, Oracle WebCenter, Oracle BPM and Oracle Social Network Product Management, OracleVidya IyerIT Delivery Manager, PanduitPatrick GarciaIT Solutions Architect, Panduit Copyright © 2014, Oracle Corporation and/or its affiliates.All rights reserved. Contact Us | Legal Notices and Terms of Use | Privacy Statement

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