null coalescing operator - Page 87

Is unnecessary error handling recommended in business logic? eg. Null check/Percentage limit check etc

- by novice_at_work

We usually put unnecessary checks in our business logic to avoid failures. Eg. 1. public ObjectABC funcABC(){ ObjectABC obj = new ObjectABC; .......... .......... //its never set to null here. .......... return obj; } ObjectABC o = funABC(); if(o!=null){ //do something } Why do we need this null check if we are sure that it will never be null? Is it a good practice or not? 2. int pplReached = funA(..,..,..); int totalPpl = funB(..,..,..); funA() just puts a few more restriction over result of funB(). Double percentage = (totalPpl==0||totalPpl<pplReached) ? 0.0 : pplReached/totalPpl; Do we again need this check? The questions is: Aren't we swallowing some fundamental issue by putting such checks? Issues which should be shown ideally, are avoided by putting these checks. What is the recommended way?

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how can i set up a uniqueness constraint in mysql for columns that can be null?

- by user299689

I know that in MySQL, UNIQUE constraits don't treat NULL values as equal. So if I have a unique constraint on ColumnX, then two separate rows can have values of NULL for ColumnX and this wouldn't violate the constraint. How can I work around this? I can't just set the value to an arbitrary constant that I can flag, because ColumnX in my case is actually a foreign key to another table. What are my options here? Please note that this table also has an "id" column that is its primary key. Since I'm using Ruby on Rails, it's important to keep this id column as the primary key. Note 2: In reality, my unique key encompasses many columns, and some of them have to be null, because they are foreign keys, and only one of them should be non-null. What I'm actually trying to do is to "simulate" a polymorphic relationship in a way that keep referential integrity in the db, but using the technique outlined in the first part of the question asked here: http://stackoverflow.com/questions/922184/why-can-you-not-have-a-foreign-key-in-a-polymorphic-association

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Why is my element variable always null in this foreach loop?

- by ZeroDivide

Here is the code: public IEnumerable<UserSummary> getUserSummaryList() { var db = new entityContext(); List<UserSummary> model = new List<UserSummary>(); List<aspnet_Users> users = (from user in db.aspnet_Users select user).ToList<aspnet_Users>(); foreach (aspnet_Users u in users) //u is always null while users is a list that contains 4 objects { model.Add(new UserSummary() { UserName = u.UserName, Email = u.aspnet_Membership.Email, Role = Roles.GetRolesForUser(u.UserName).First(), AdCompany = u.AD_COMPANIES.ad_company_name != null ? u.AD_COMPANIES.ad_company_name : "Not an Advertiser", EmployeeName = u.EMPLOYEE.emp_name != null ? u.EMPLOYEE.emp_name : "Not an Employee" }); } return model; } For some reason the u variable in the foreach loop is always null. I've stepped through the code and the users collection is always populated. The table entity for db.aspnet_Users is the users table that comes with asp.net membership services. I've only added a couple associations to it. edit : image of debugger

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If a table has two xml columns, will inserting records be a lot slower?

- by Lieven Cardoen

Is it a bad thing to have two xml columns in one table? + How much slower are these xml columns in terms of updating/inserting/reading data? In profiler this kind of insert normally takes 0 ms, but sometimes it goes up to 160ms: declare @p8 xml set @p8=convert(xml,N'<interactions><interaction correct="false" score="0" id="0" gapid="0" x="61" y="225"><feedback/><element id="0" position="0" elementtype="1"><asset/></element></interaction><interaction correct="false" score="0" id="1" gapid="1" x="64" y="250"><feedback/><element id="0" position="0" elementtype="1"><asset/></element></interaction><interaction correct="false" score="0" id="2" gapid="2" x="131" y="250"><feedback/><element id="0" position="0" elementtype="1"><asset/></element></interaction></interactions>') declare @p14 xml set @p14=convert(xml,N'<contentinteractions/>') exec sp_executesql N'INSERT INTO [dbo].[PackageSessionNodes]([dbo].[PackageSessionNodes].[PackageSessionId], [dbo].[PackageSessionNodes].[TreeNodeId],[dbo].[PackageSessionNodes].[Duration], [dbo].[PackageSessionNodes].[Score],[dbo].[PackageSessionNodes].[ScoreMax], [dbo].[PackageSessionNodes].[Interactions],[dbo].[PackageSessionNodes].[BrainTeaser], [dbo].[PackageSessionNodes].[DateCreated], [dbo].[PackageSessionNodes].[CompletionStatus], [dbo].[PackageSessionNodes].[ReducedScore], [dbo].[PackageSessionNodes].[ReducedScoreMax], [dbo].[PackageSessionNodes].[ContentInteractions]) VALUES (@ins_dboPackageSessionNodesPackageSessionId, @ins_dboPackageSessionNodesTreeNodeId, @ins_dboPackageSessionNodesDuration, @ins_dboPackageSessionNodesScore, @ins_dboPackageSessionNodesScoreMax, @ins_dboPackageSessionNodesInteractions, @ins_dboPackageSessionNodesBrainTeaser, @ins_dboPackageSessionNodesDateCreated, @ins_dboPackageSessionNodesCompletionStatus, @ins_dboPackageSessionNodesReducedScore, @ins_dboPackageSessionNodesReducedScoreMax, @ins_dboPackageSessionNodesContentInteractions) ; SELECT SCOPE_IDENTITY() as new_id This is the table: CREATE TABLE [dbo].[PackageSessionNodes]( [PackageSessionNodeId] [int] IDENTITY(1,1) NOT NULL, [PackageSessionId] [int] NOT NULL, [TreeNodeId] [int] NOT NULL, [Duration] [int] NULL, [Score] [float] NOT NULL, [ScoreMax] [float] NOT NULL, [Interactions] [xml] NOT NULL, [BrainTeaser] [bit] NOT NULL, [DateCreated] [datetime] NULL, [CompletionStatus] [int] NOT NULL, [ReducedScore] [float] NOT NULL, [ReducedScoreMax] [float] NOT NULL, [ContentInteractions] [xml] NOT NULL, CONSTRAINT [PK_PackageSessionNodes] PRIMARY KEY CLUSTERED ( [PackageSessionNodeId] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO ALTER TABLE [dbo].[PackageSessionNodes] WITH CHECK ADD CONSTRAINT [FK_PackageSessionNodes_PackageSessions] FOREIGN KEY([PackageSessionId]) REFERENCES [dbo].[PackageSessions] ([PackageSessionId]) ON UPDATE CASCADE ON DELETE CASCADE GO ALTER TABLE [dbo].[PackageSessionNodes] CHECK CONSTRAINT [FK_PackageSessionNodes_PackageSessions] GO ALTER TABLE [dbo].[PackageSessionNodes] WITH CHECK ADD CONSTRAINT [FK_PackageSessionNodes_TreeNodes] FOREIGN KEY([TreeNodeId]) REFERENCES [dbo].[TreeNodes] ([TreeNodeId]) GO ALTER TABLE [dbo].[PackageSessionNodes] CHECK CONSTRAINT [FK_PackageSessionNodes_TreeNodes] GO ALTER TABLE [dbo].[PackageSessionNodes] ADD CONSTRAINT [DF_PackageSessionNodes_Score] DEFAULT ((-1)) FOR [Score] GO ALTER TABLE [dbo].[PackageSessionNodes] ADD CONSTRAINT [DF_PackageSessionNodes_ScoreMax] DEFAULT ((-1)) FOR [ScoreMax] GO ALTER TABLE [dbo].[PackageSessionNodes] ADD CONSTRAINT [DF_PackageSessionNodes_DateCreated] DEFAULT (getdate()) FOR [DateCreated] GO ALTER TABLE [dbo].[PackageSessionNodes] ADD CONSTRAINT [DF_PackageSessionNodes_ReducedScore] DEFAULT ((-1)) FOR [ReducedScore] GO ALTER TABLE [dbo].[PackageSessionNodes] ADD CONSTRAINT [DF_PackageSessionNodes_ReducedScoreMax] DEFAULT ((-1)) FOR [ReducedScoreMax] GO

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Search field based on multiple parameter

- by Manoj Wadhwani

Can anybody modify this , when i insert Emp. name it go to first search and it does not check other paramete could you plz modify this sp for exact search on based on parameter. --select * from Training_TRNS --USP_SearchEmployee '','2008-04-18 00:00:00.000','','','','','' alter Procedure USP_SearchEmployee @EmpName varchar(100)=null, @DateFrom varchar(100)=null, @DateTo varchar(100)=null, @CourseName varchar(100)=null, @JobFunction varchar(100)=null, @Region varchar(100)=null, @Status varchar(100)=null AS BEGIN if (@EmpName!='' and @EmpName is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where EmpName like '%'+@EmpName+'%' END ELSE IF (@CourseName!='' and @CourseName is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where SpeCourse_ID like '%'+@CourseName+'%' END ELSE IF (@JobFunction!='' and @JobFunction is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where EmpJobFunction like '%'+@JobFunction+'%' END ELSE IF (@Region!='' and @Region is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where EmpRegion like '%'+@Region+'%' END ELSE IF (@Status!='' and @Status is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where Status like '%'+@Status+'%' END ELSE IF (@DateFrom!='' and @DateFrom is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where convert(varchar,DueDate,101) like '%'+convert(varchar,@DateFrom,101)+'%' END Else BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS END END

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How to Implement search through Stored Procedure

- by Manoj Wadhwani

Can Any budy update thie sp for search , i think i have put search condition which is not rigth . If you have expertise in sql then update it , It's very urgent i have to upload it toady .. alter Procedure USP_SearchEmployee @EmpName varchar(100)=null, @DateFrom varchar(100)=null, @DateTo varchar(100)=null, @CourseName varchar(100)=null, @JobFunction varchar(100)=null, @Region varchar(100)=null, @Status varchar(100)=null AS BEGIN if (@EmpName!='' or @EmpName is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where EmpName like '%'+@EmpName+'%' END ELSE IF (@CourseName!='' or @CourseName is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where SpeCourse_ID like '%'+@CourseName+'%' END ELSE IF (@JobFunction!='' or @JobFunction is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where EmpJobFunction like '%'+@JobFunction+'%' END ELSE IF (@Region!='' or @Region is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where EmpRegion like '%'+@Region+'%' END ELSE IF (@Status!='' or @Status is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where Status like '%'+@Status+'%' END ELSE IF (@DateFrom!='' or @DateFrom is not null) BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS where convert(varchar,DueDate,101) =convert(varchar,@DateFrom,101) END Else BEGIN select EmpName,convert(varchar,DueDate,101) as DueDate,SpeCourse_ID as CourseName, EmpJobFunction as JOBFunction,EmpRegion as Region,Status from Training_TRNS END END

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Please help! Delegate returns null via Dipendency Injection.

- by Raj Aththanayake

Can someone please help? I use Google code’s Moq framework for mocking within my Unit Tests and Unity for Dependency Injection. In my Test class private Mock<ICustomerSearchService> CustomerSearchServiceMock = null; private CustomerService customerService = null; private void SetupMainData() { CustomerSearchServiceMock = new Mock<ICustomerSearchService>(); customerService = new CustomerService (); // CustomerSearchService is a property in CustomerService and dependency is configuered via Unity customerService.CustomerSearchService = CustomerSearchServiceMock.Object; Customer c = new Customer () { ID = "AT" }; CustomerSearchServiceMock.Setup(s => s.GetCustomer(EqualsCondition)).Returns(c); } [TestMethod] public void GetCustomerData_Test_Method() { SetupMainData() var customer = customerService.GetCustomerData("AT"); } public static bool EqualsCondition(Customer customer) { return customer.ID.Equals("AT"); } In my Test class CustomerService class public class CustomerService : ICustomerService { [Dependency] public ICustomerSearchService CustomerSearchService { get; set; } public IEnumerable<SomeObject> GetCustomerData(string custID) { I GET Null for customer ?????} var customer = CustomerSearchService.GetCustomer (c => c.ID.Equals(custID)); //Do more things } } When I debug the code I can see CustomerSearchService has a proxy object, but the customer returns as null. Any ideas? Or is there something missing here? Note: ICustomerSearchService I have implemented below method. Customer GetCustomer(Func<Customer, bool> predicate);

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Finding 'free' times in MySQL

- by James Inman

Hi, I've got a table as follows: mysql> DESCRIBE student_lectures; +------------------+----------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +------------------+----------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | course_module_id | int(11) | YES | MUL | NULL | | | day | int(11) | YES | | NULL | | | start | datetime | YES | | NULL | | | end | datetime | YES | | NULL | | | cancelled_at | datetime | YES | | NULL | | | lecture_type_id | int(11) | YES | | NULL | | | lecture_id | int(11) | YES | | NULL | | | student_id | int(11) | YES | | NULL | | | created_at | datetime | YES | | NULL | | | updated_at | datetime | YES | | NULL | | +------------------+----------+------+-----+---------+----------------+ I'm essentially wanting to find times when a lecture doesn't happen - so to do this I'm thinking a query to group overlapping lectures together (so, for example, 9am-10am and 10am-11am lectures will be shown as a single 9am-11am lecture). There may be more than two lectures back-to-back. I've currently got this: SELECT l.start, l2.end FROM student_lectures l LEFT JOIN student_lectures l2 ON ( l2.start = l.end ) WHERE l.student_id = 1 AND l.start >= '2010-04-26 09:00:00' AND l.end <= '2010-04-30 19:00:00' AND l2.end IS NOT NULL AND l2.end != l.start GROUP BY l.start, l2.end ORDER BY l.start, l2.start Which returns: +---------------------+---------------------+ | start | end | +---------------------+---------------------+ | 2010-04-26 09:00:00 | 2010-04-26 11:00:00 | | 2010-04-26 10:00:00 | 2010-04-26 12:00:00 | | 2010-04-26 10:00:00 | 2010-04-26 13:00:00 | | 2010-04-26 13:15:00 | 2010-04-26 16:15:00 | | 2010-04-26 14:15:00 | 2010-04-26 16:15:00 | | 2010-04-26 15:15:00 | 2010-04-26 17:15:00 | | 2010-04-26 16:15:00 | 2010-04-26 18:15:00 | ...etc... The output I'm looking for from this would be: +---------------------+---------------------+ | start | end | +---------------------+---------------------+ | 2010-04-26 09:00:00 | 2010-04-26 13:00:00 | | 2010-04-26 13:15:00 | 2010-04-26 18:15:00 | Any help appreciated, thanks!

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Cookies NULL On Some ASP.NET Pages (even though it IS there!)

- by DaveDev

Hi folks I'm working on an ASP.NET application and I'm having difficulty in understanding why a cookie appears to be null. On one page (results.aspx) I create a cookie, adding entries every time the user clicks a checkbox. When the user clicks a button, they're taken to another page (graph.aspx) where the contents of that cookie is read. The problem is that the cookie doesn't seem to exist on graph.aspx. The following code returns null: Request.Cookies["MyCookie"]; The weird thing is this is only an issue on our staging server. This app is deployed to a production server and it's fine. It also works perfectly locally. I've put debug code on both pages: StringBuilder sb = new StringBuilder(); foreach (string cookie in Request.Cookies.AllKeys) { sb.Append(cookie.ToString() + "<br />"); } this.divDebugOutput.InnerHtml = sb.ToString(); On results.aspx (where there are no problems), I can see the cookies are: MyCookie __utma __utmb __utmz _csoot _csuid ASP.NET_SessionId __utmc On graph.aspx, you can see there is no 'MyCookie' __utma __utmb __utmz _csoot _csuid ASP.NET_SessionId __utmc With that said, if I take a look with my FireCookie, I can see that the same cookie does in fact exist on BOTH pages! WTF?!?!?!?! (ok, rant over :-) ) Has anyone seen something like this before? Why would ASP.NET claim that a cookie is null on one page, and not null on another?

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Working with Reporting Services Filters–Part 1

- by smisner

There are two ways that you can filter data in Reporting Services. The first way, which usually provides a faster performance, is to use query parameters to apply a filter using the WHERE clause in a SQL statement. In that case, the structure of the filter depends upon the syntax recognized by the source database. Another way to filter data in Reporting Services is to apply a filter to a dataset, data region, or a group. Using this latter method, you can even apply multiple filters. However, the use of filter operators or the setup of multiple filters is not always obvious, so in this series of posts, I'll provide some more information about the configuration of filters. First, why not use query parameters exclusively for filtering? Here are a few reasons: You might want to apply a filter to part of the report, but not all of the report. Your dataset might retrieve data from a stored procedure, and doesn't allow you to pass a query parameter for filtering purposes. Your report might be set up as a snapshot on the report server and, in that case, cannot be dynamically filtered based on a query parameter. Next, let's look at how to set up a report filter in general. The process is the same whether you are applying the filter to a dataset, data region, or a group. When you go to the Filters page in the Properties dialog box for whichever of these items you selected (dataset, data region, group), you click the Add button to create a new filter. The interface looks like this: The Expression field is usually a field in the dataset, so to make it easier for you to make a selection,the drop-down list displays all of the current dataset fields. But notice the expression button to the right, which means that you can set up any type of expression-not just a dataset field. To the right of the expression button, you'll find a data type drop-down list. It's important to specify the correct data type for the field or expression you're using. Now for the operators. Here's a list of the options that you have: This Operator Performs This Action =, <>, >, >=, <, <=, Like Compares expression to value Top N, Bottom N Compares expression to Top (Bottom) set of N values (N = integer) Top %, Bottom % Compares expression to Top (Bottom) N percent of values (N = integer or float) Between Determines whether expression is between two values, inclusive In Determines whether expression is found in list of values Last, the Value is what you're comparing to the expression using the operator. The construction of a filter using some operators (=, <>, >, etc.) is fairly simple. If my dataset (for AdventureWorks data) has a Category field, and I have a parameter that prompts the user for a single category, I can set up a filter like this: Expression Data Type Operator Value [Category] Text = [@Category] But if I set the parameter to accept multiple values, I need to change the operator from = to In, just as I would have to do if I were using a query parameter. The parameter expression, [@Category], which translates to =Parameters!Category.Value, doesn’t need to change because it represents an array as soon as I change the parameter to allow multiple values. The “In” operator requires an array. With that in mind, let’s consider a variation on Value. Let’s say that I have a parameter that prompts the user for a particular year – and for simplicity’s sake, this parameter only allows a single value, and I have an expression that evaluates the previous year based on the user’s selection. Then I want to use these two values in two separate filters with an OR condition. That is, I want to filter either by the year selected OR by the year that was computed. If I create two filters, one for each year (as shown below), then the report will only display results if BOTH filter conditions are met – which would never be true. Expression Data Type Operator Value [CalendarYear] Integer = [@Year] [CalendarYear] Integer = =Parameters!Year.Value-1 To handle this scenario, we need to create a single filter that uses the “In” operator, and then set up the Value expression as an array. To create an array, we use the Split function after creating a string that concatenates the two values (highlighted in yellow) as shown below. Expression Data Type Operator Value =Cstr(Fields!CalendarYear.Value) Text In =Split( CStr(Parameters!Year.Value) + ”,” + CStr(Parameters!Year.Value-1) , “,”) Note that in this case, I had to apply a string conversion on the year integer so that I could concatenate the parameter selection with the calculated year. Pay attention to the second argument of the Split function—you must use a comma delimiter for the result to work correctly with the In operator. I also had to change the Expression value from [CalendarYear] (or =Fields!CalendarYear.Value) so that the expression would return a string that I could compare with the values in the string array. More fun with filter expressions in future posts!

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DENY select on sys.dm_db_index_physical_stats

- by steveh99999

Technorati Tags: security,DMV,permission,sys.dm_db_index_physical_stats I recently saw an interesting blog article by Paul Randal about the performance overhead of querying the sys.dm_db_index_physical_stats. So I was thinking, would it be possible to let non-sysadmin users query DMVs on a SQL server but stop them querying this I/O intensive DMV ? Yes it is, here’s how… 1. Create a new login for test purposes, with permissions to access AdventureWorks database only … CREATE LOGIN [test] WITH PASSWORD='xxxx', DEFAULT_DATABASE=[AdventureWorks] GO USE [AdventureWorks] GO CREATE USER [test] FOR LOGIN [test] WITH DEFAULT_SCHEMA=[dbo] GO 2.login as user test and issue command SELECT * FROM sys.dm_db_index_physical_stats(DB_ID('AdventureWorks'),NULL,NULL,NULL,'DETAILED') gets error :- Msg 297, Level 16, State 12, Line 1 The user does not have permission to perform this action. 3.As a sysadmin, issue command :- USE AdventureWorks GRANT VIEW DATABASE STATE TO [test] or GRANT VIEW SERVER STATE TO [test] if all databases can be queried via DMV. 4. Try again as user test to issue command SELECT * FROM sys.dm_db_index_physical_stats(DB_ID('AdventureWorks '),NULL,NULL,NULL,'DETAILED') -- now produces valid results from the DMV.. 5 now create the test user in master database, public role only USE master CREATE USER [test] FOR LOGIN [test] 6 issue command :- USE master DENY SELECT ON sys.dm_db_index_physical_stats TO [test] 7 Now go back to AdventureWorks using test login and try SELECT * FROM sys.dm_db_index_physical_stats(DB_ID('AdventureWorks’),NULL,NULL,NULL,’DETAILED') Now gets error... Msg 229, Level 14, State 5, Line 1 The SELECT permission was denied on the object 'dm_db_index_physical_stats', database 'mssqlsystemresource', schema 'sys'. but the user is still able to query all other non-IO-intensive DMVs. If the user attempts to view the index physical stats via a builtin management studio report – see recent blog post by Pinal Dave they get an error also

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Need help to debug application using .Net and MySQL

- by Tim Murphy

What advice can you give me on how to track down a bug I have while inserting data into MySQL database with .Net? The error message is: MySql.Data.MySqlClient.MySqlException: Duplicate entry '26012' for key 'StockNumber_Number_UNIQUE' Reviewing of the log proves that StockNumber_Number of 26012 has not been inserted yet. Products in use. Visual Studio 2008. mysql.data.dll 6.0.4.0. Windows 7 Ultimate 64 bit and Windows 2003 32 bit. Custom built ORM framework (have source code). Importing data from Access 2003 database. The code works fine for 3000 - 5000 imports. The record being imported that causes the problem in a full run works fine if just importing by itself. I've also seen the error on other records if I sort the data to be imported a different way. Have tried import with and without transactions. Have logged the hell out of the system. The SQL command to create the table: CREATE TABLE `RareItems_RareItems` ( `RareItemKey` CHAR(36) NOT NULL PRIMARY KEY, `StockNumber_Text` VARCHAR(7) NOT NULL, `StockNumber_Number` INT NOT NULL AUTO_INCREMENT, UNIQUE INDEX `StockNumber_Number_UNIQUE` (`StockNumber_Number` ASC), `OurPercentage` NUMERIC , `SellPrice` NUMERIC(19, 2) , `Author` VARCHAR(250) , `CatchWord` VARCHAR(250) , `Title` TEXT , `Publisher` VARCHAR(250) , `InternalNote` VARCHAR(250) , `DateOfPublishing` VARCHAR(250) , `ExternalNote` LONGTEXT , `Description` LONGTEXT , `Scrap` LONGTEXT , `SuppressionKey` CHAR(36) NOT NULL, `TypeKey` CHAR(36) NOT NULL, `CatalogueStatusKey` CHAR(36) NOT NULL, `CatalogueRevisedDate` DATETIME , `CatalogueRevisedByKey` CHAR(36) NOT NULL, `CatalogueToBeRevisedByKey` CHAR(36) NOT NULL, `DontInsure` BIT NOT NULL, `ExtraCosts` NUMERIC(19, 2) , `IsWebReady` BIT NOT NULL, `LocationKey` CHAR(36) NOT NULL, `LanguageKey` CHAR(36) NOT NULL, `CatalogueDescription` VARCHAR(250) , `PlacePublished` VARCHAR(250) , `ToDo` LONGTEXT , `Headline` VARCHAR(250) , `DepartmentKey` CHAR(36) NOT NULL, `Temp1` INT , `Temp2` INT , `Temp3` VARCHAR(250) , `Temp4` VARCHAR(250) , `InternetStatusKey` CHAR(36) NOT NULL, `InternetStatusInfo` LONGTEXT , `PurchaseKey` CHAR(36) NOT NULL, `ConsignmentKey` CHAR(36) , `IsSold` BIT NOT NULL, `RowCreated` DATETIME NOT NULL, `RowModified` DATETIME NOT NULL ); The SQL command and parameters to insert the record: INSERT INTO `RareItems_RareItems` (`RareItemKey`, `StockNumber_Text`, `StockNumber_Number`, `OurPercentage`, `SellPrice`, `Author`, `CatchWord`, `Title`, `Publisher`, `InternalNote`, `DateOfPublishing`, `ExternalNote`, `Description`, `Scrap`, `SuppressionKey`, `TypeKey`, `CatalogueStatusKey`, `CatalogueRevisedDate`, `CatalogueRevisedByKey`, `CatalogueToBeRevisedByKey`, `DontInsure`, `ExtraCosts`, `IsWebReady`, `LocationKey`, `LanguageKey`, `CatalogueDescription`, `PlacePublished`, `ToDo`, `Headline`, `DepartmentKey`, `Temp1`, `Temp2`, `Temp3`, `Temp4`, `InternetStatusKey`, `InternetStatusInfo`, `PurchaseKey`, `ConsignmentKey`, `IsSold`, `RowCreated`, `RowModified`) VALUES (@RareItemKey, @StockNumber_Text, @StockNumber_Number, @OurPercentage, @SellPrice, @Author, @CatchWord, @Title, @Publisher, @InternalNote, @DateOfPublishing, @ExternalNote, @Description, @Scrap, @SuppressionKey, @TypeKey, @CatalogueStatusKey, @CatalogueRevisedDate, @CatalogueRevisedByKey, @CatalogueToBeRevisedByKey, @DontInsure, @ExtraCosts, @IsWebReady, @LocationKey, @LanguageKey, @CatalogueDescription, @PlacePublished, @ToDo, @Headline, @DepartmentKey, @Temp1, @Temp2, @Temp3, @Temp4, @InternetStatusKey, @InternetStatusInfo, @PurchaseKey, @ConsignmentKey, @IsSold, @RowCreated, @RowModified) @RareItemKey = 0b625bd6-776d-43d6-9405-e97159d172a6 @StockNumber_Text = 199305 @StockNumber_Number = 26012 @OurPercentage = 22.5 @SellPrice = 1250 @Author = SPARRMAN, Anders. @CatchWord = COOK: SECOND VOYAGE @Title = A Voyage Round the World with Captain James Cook in H.M.S. Resolution… Introduction and notes by Owen Rutter, wood engravings by Peter Barker-Mill. @Publisher = @InternalNote = @DateOfPublishing = 1944 @ExternalNote = The first English translation of Sparrman’s narrative, which had originally been published in Sweden in 1802-1818, and the only complete version of his account to appear in English. The eighteenth-century translation had appeared some time before the Swedish publication of the final sections of his account. Sparrman’s observant and well-written narrative of the second voyage contains much that appears nowhere else, emphasising naturally his interests in medicine, health, and natural history.<br><br>One of 350 numbered copies: a handsomely produced and beautifully illustrated work. @Description = Small folio, wood-engravings in the text; original olive glazed cloth, top edges gilt, a very good copy. London, Golden Cockerel Press, 1944. @Scrap = @SuppressionKey = 00000000-0000-0000-0000-000000000000 @TypeKey = 93f58155-7471-46ad-84c5-262ab9dd37e8 @CatalogueStatusKey = 00000000-0000-0000-0000-000000000003 @CatalogueRevisedDate = @CatalogueRevisedByKey = c4f6fc06-956d-44c4-b393-0d5462cbffec @CatalogueToBeRevisedByKey = 00000000-0000-0000-0000-000000000000 @DontInsure = False @ExtraCosts = @IsWebReady = False @LocationKey = 00000000-0000-0000-0000-000000000000 @LanguageKey = 00000000-0000-0000-0000-000000000000 @CatalogueDescription = @PlacePublished = Golden Cockerel Press @ToDo = @Headline = @DepartmentKey = 529578a3-9189-40de-b656-eef9039d00b8 @Temp1 = @Temp2 = @Temp3 = @Temp4 = v @InternetStatusKey = 00000000-0000-0000-0000-000000000000 @InternetStatusInfo = @PurchaseKey = 00000000-0000-0000-0000-000000000000 @ConsignmentKey = @IsSold = True @RowCreated = 8/04/2010 8:49:16 PM @RowModified = 8/04/2010 8:49:16 PM Suggestions on what is causing the error and/or how to track down what is causing the problem?

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Mysql 100% CPU + Slow query

- by felipeclopes

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C++ templates - matrix class

- by lastOfMohicans

Hi I'm learning templates in C++ so I decied to write matrix class which would be a template class. In Matrix.h file I wrote #pragma once #include "stdafx.h" #include <vector> using namespace std; template<class T> class Matrix { public: Matrix(); ~Matrix(); GetDataVector(); SetDataVector(vector<vector<T>> dataVector); bool operator == (Matrix* matrix); bool operator < (Matrix* matrix); bool operator <= (Matrix* matrix); bool operator > (Matrix* matrix); bool operator >= (Matrix* matrix); Matrix* operator + (Matrix* matrix); Matrix* operator - (Matrix* matrix); Matrix* operator * (Matrix* matrix); private: vector<vector<T>> datavector; int columns,rows; }; In Matrix cpp Visual Stuio automaticlly generated code for default constructors #include "StdAfx.h" #include "Matrix.h" Matrix::Matrix() { } Matrix::~Matrix() { } However if I want to compile this I get an error 'Matrix' : use of class template requires template argument list The error are in file Matrix.cpp in default constructors What may be the problem ??

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ICommand.CanExecute being passed null even though CommandParameter is set...

- by chaiguy

I have a tricky problem where I am binding a ContextMenu to a set of ICommand-derived objects, and setting the Command and CommandParameter properties on each MenuItem via a style: <ContextMenu ItemsSource="{Binding Source={x:Static OrangeNote:Note.MultiCommands}}"> <ContextMenu.Resources> <Style TargetType="MenuItem"> <Setter Property="Header" Value="{Binding Path=Title}" /> <Setter Property="Command" Value="{Binding}" /> <Setter Property="CommandParameter" Value="{Binding Source={x:Static OrangeNote:App.Screen}, Path=SelectedNotes}" /> ... However, while ICommand.Execute( object ) gets passed the set of selected notes as it should, ICommand.CanExecute( object ) (which is called when the menu is created) is getting passed null. I've checked and the selected notes collection is properly instantiated before the call is made (in fact it's assigned a value in its declaration, so it is never null). I can't figure out why CanEvaluate is getting passed null.

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How to test a lamda expression var query result is null?

- by mike

var query = from emp in dbEmp.Employees join dept in dbEmp.Departments on emp.DeptID equals dept.DeptID where dept.DepartmentName.Contains(this.TextBox1.Text) select new { EmpID = emp.EmpID, EmpName = emp.EmpName, Age = emp.Age, Address = emp.Address, DeptName = dept.DepartmentName }; if (query==null) Label1.Text = "no results match your search"; GridView1.DataSource = query; GridView1.DataBind(); Everything works in the right way, but the label doesn't show the message when query result returns null. The label can show without condition(querry==null). So how to test if a var query result returns nothing? Thanks

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how to write extension method to check string value is null or not.

- by kumar

Hi all, (LocalVariable)ABC.string(Name)= (Idatareader)datareader.GetString(0); this name value is coming from database.. what happening here is if this name value is null while reading it's throwing an exception? I am manually doing some if condition here. I don't want to write a manual condition to check all my variables.. I am doing something like this now.. string abc = (Idatareader)datareader.GetValue(0); if(abc = null) //assiging null else assiging abc value is there something like can we write extension method for this? thanks

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Any sense to set obj = null(Nothing) in Dispose()?

- by serhio

Is there any sense to set custom object to null(Nothing in VB.NET) in the Dispose() method? Could this prevent memory leaks or it's useless?! Let's consider two examples: public class Foo : IDisposable { private Bar bar; // standard custom .NET object public Foo(Bar bar) { this.bar = bar; } public void Dispose() { bar = null; // any sense? } } public class Foo : RichTextBox { // this could be also: GDI+, TCP socket, SQl Connection, other "heavy" object private Bitmap backImage; public Foo(Bitmap backImage) { this.backImage = backImage; } protected override void Dispose(bool disposing) { if (disposing) { backImage = null; // any sense? } } }

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Why is rails setting ":null => false" on all my columns in schema.rb?

- by ryeguy

Even if I never specify :null => false in my migrations that initially add columns to tables, rails still generates code in schema.rb that specifies the columns as having :null => false. Why is this? If I develop on my box, and then use rake db:schema:load on my production box, I'm going to get very different behavior! Edit: Even if I delete schema.rb and run rake db:schema:dump, it still puts :null => false on the new schema even if it isn't defined like that in the actual database. It seems it can't tell whether or not a column is marked as allowing nulls. I'm using SQLite if that helps.

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How can a FILE* (pointer to a struct) be tested (if == NULL)?

- by m4design

I was playing around with C, anyways I was thinking how can file pointer (which points to a struct type), be tested if NULL as for instant: FILE *cfPtr; if ( ( cfPtr = fopen( "file.dat", "w" ) ) == NULL ) I tried to do that myself, but an error occurs. struct foo{ int x; }; struct foo bar = {0}; if (bar == NULL) puts("Yay\n"); else puts("Nay"); error C2088: '==' : illegal for struct Here's the FILE deceleration in the stdio.h file: struct _iobuf { char *_ptr; int _cnt; char *_base; int _flag; int _file; int _charbuf; int _bufsiz; char *_tmpfname; }; typedef struct _iobuf FILE;

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How to check if the internal typedef struct of a typedef struct is NULL ?

- by watchloop

typedef struct { uint32 item1; uint32 item2; uint32 item3; uint32 item4; <some_other_typedef struct> *table; } Inner_t; typedef struct { Inner_t tableA; Inner_t tableB; } Outer_t; Outer_t outer_instance = { {NULL}, { 0, 1, 2, 3, table_defined_somewhere_else, } }; My question is how to check if tableA is NULL just like the case for outer_instance. It tried: if ( tmp->tableA == NULL ). I get "error: invalid operands to binary =="

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How can i do re coding without assign null value?

- by Phsika

How can i do below without assign null value "Tex=null"? static void Main(string[] args) { FileInfo f = new FileInfo("C:/temp/Arungg.txt"); StreamWriter Tex; Tex = null; if (!f.Exists) { f.CreateText(); } else { Tex = f.AppendText(); } Tex.WriteLine("Test1"); Tex.WriteLine("Test2"); Tex.Write(Tex.NewLine); Tex.Close(); Console.WriteLine(" The Text file named Arungg is created "); }

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C++ STL question related to insert iterators and overloaded operators

- by rshepherd

#include <list> #include <set> #include <iterator> #include <algorithm> using namespace std; class MyContainer { public: string value; MyContainer& operator=(const string& s) { this->value = s; return *this; } }; int main() { list<string> strings; strings.push_back("0"); strings.push_back("1"); strings.push_back("2"); set<MyContainer> containers; copy(strings.begin(), strings.end(), inserter(containers, containers.end())); } The preceeding code does not compile. In standard C++ fashion the error output is verbose and difficult to understand. The key part seems to be this... /usr/include/c++/4.4/bits/stl_algobase.h:313: error: no match for ‘operator=’ in ‘__result.std::insert_iterator::operator* [with _Container = std::set, std::allocator ]() = __first.std::_List_iterator::operator* [with _Tp = std::basic_string, std::allocator ]()’ ...which I interpet to mean that the assignment operator needed is not defined. I took a look at the source code for insert_iterator and noted that it has overloaded the assignment operator. The copy algorithm must uses the insert iterators overloaded assignment operator to do its work(?). I guess that because my input iterator is on a container of strings and my output iterator is on a container of MyContainers that the overloaded insert_iterator assignment operator can no longer work. This is my best guess, but I am probably wrong. So, why exactly does this not work and how can I accomplish what I am trying to do?

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Why would a 'public event EventHandler cccc' be null?

- by Matt

Why would a 'public event EventHandler cccc' be null? I have a class that's public class Builder { public event EventHandler StartedWorking; public Builder() { // Constructor does some stuff } public void Start() { StartedWorking(this, eventargobject); //StartedWorking is null -- } } This seems straightforward and something I do all the time? Am I missing something obvious or is there something that could cause this? EDIT: Does this mean that if I fire an event that is not subscribed to in a client class I have to check that it is not null? EDIT-2: I guess I'd never had events that were never not subscribed to and hence never ran into this -- You learn something new every day Sorry about the seemingly stupid question....

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C++ STL question related to insert iterators and sets

- by rshepherd

#include #include #include #include using namespace std; class MyContainer { public: string value; MyContainer& operator=(const string& s) { this->value = s; return *this; } }; int main() { list<string> strings; strings.push_back("0"); strings.push_back("1"); strings.push_back("2"); set<MyContainer> containers; copy(strings.begin(), strings.end(), inserter(containers, containers.end())); } The preceeding code does not compile. In typical STL style the error output is verbose and difficult to understand. The key part seems to be this... /usr/include/c++/4.4/bits/stl_algobase.h:313: error: no match for ‘operator=’ in ‘__result.std::insert_iterator::operator* [with _Container = std::set, std::allocator ]() = __first.std::_List_iterator::operator* [with _Tp = std::basic_string, std::allocator ]()’ ...which I interpet to mean that the assignment operator needed is not defined. I took a look at the source code for insert_iterator and noted that it has overloaded the assignment operator. The copy algorithm must uses the insert iterators overloaded assignment operator to do its work(?). I guess that because my input iterator is on a container of strings and my output iterator is on a container of MyContainers that the overloaded insert_iterator assignment operator can no longer work. This is my best guess, but I am probably wrong. So, why exactly does this not work and how can I accomplish what I am trying to do?

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