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  • Can't get Sum() working in Northwind example

    - by Vince
    Hi, The following code is generating a runtime error and I have no idea why. from o in Orders group o by o.Employee into employeeOrders select new { employeeOrders.Key.EmployeeID, employeeOrders.Key.FirstName, Orders = from eord in employeeOrders orderby eord.OrderID select new { eord.OrderID, eord.OrderDate, OrderTotal=eord.OrderDetails.Sum (od => od.UnitPrice) } } The error is Member access 'System.Decimal UnitPrice' of 'LINQPad.User.OrderDetails' not legal on type 'LINQPad.User.Orders I've also tried this in VS2010 with a standard drag and drop data context and same thing. Thanks in advance

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  • Linq ChangeConflictException (ASP.NET MVC) - occurs when submitting DataContext changes

    - by Alex
    System.Data.Linq.ChangeConflictException: 2 of X updates failed. at System.Data.Linq.ChangeProcessor.SubmitChanges(ConflictMode failureMode) at System.Data.Linq.DataContext.SubmitChanges(ConflictMode failureMode) at PROJECT.Controllers.HomeController.ClickProc(Int32 id, String code, String n) This is what I get very often. This action is done thousands of times a day, and I get this exception about once every 5 seconds. From what I understand it happens when something changes in the database in the period between creating DataContext and updating it. Am I right? What's the problem here and how can I fix it?

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  • How can I join on a CSV varchar?

    - by mgroves
    I have a varchar field that contains a string like "10,11,12,13". How can I use that CSV string to join to another table with those IDs? Here's the approach I'm taking now: select * from SomeTable a WHERE (',' + @csvString + ',') LIKE '%,' + CONVERT(varchar(25), a.ID) + ',%' Where @csvString is "10,11,12,...". I intend to use this method as a join condition as well. That method works, but it's rather slow (using CAST doesn't improve the speed). I understand that having CSVs in the database like that is usually a very silly idea in most cases, but there's nothing I can do about that.

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  • Question About TransactionScope in .NET

    - by peace
    using (TransactionScope scope = new TransactionScope()) { int updatedRows1 = custPh.Update(cust.CustomerID, tempPh1, 0); int updatedRows2 = custPh.Update(cust.CustomerID, tempPh2, 1); int updatedRows3 = cust.Update(); if (updatedRows1 > 0 && updatedRows2 > 0 && updatedRows3 > 0) { scope.Complete(); } } Is the above TransactionScope code structured correctly? This is my first time using it so i'm trying to make as simple as i can.

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  • Complicated SQL query

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

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  • LINQ2SQL: how to merge two columns from the same table into a single list

    - by TomL
    this is probably a simple question, but I'm only a beginner so... Suppose I have a table containing home-work locations (cities) certain people use. Something like: ID(int), namePerson(string), homeLocation(string), workLocation(string) where homeLocation and workLocation can both be null. Now I want all the different locations that are used merged into a single list. Something like: var homeLocation = from hm in Places where hm.Home != null select hm.Home; var workLocation = from wk in Places where wk.Work != null select wk.Work; List<string> locationList = new List<string>(); locationList = homeLocation.Distinct().ToList<string>(); locationList.AddRange(workLocation.Distinct().ToList<string>()); (which I guess would still allow duplicates if they have the same value in both columns, which I don't really want...) My question: how this be put into a single LINQ statement? Thanks in advance for your help!

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  • Select where and where not

    - by Simon
    I have a table containing lessons that I called "cours" (french) and I have several cours inside and I have linked them to students with a table between them to see if they go to the lessons or not. I would like to return data with the SELECT and the data that are NOT select. So, If one student follow 3 courses of 5, I would like to return the 3 courses that he follow and the 2 courses that he doesn't follow. Is there a way to do it ?

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  • Extract multiple values from one column in MySql

    - by Neil
    I've noticed that MySql has an extensive search capacity, allowing both wildcards and regular expressions. However, I'm in somewhat in a bind since I'm trying to extract multiple values from a single string in my select query. For example, if I had the text "<span>Test</span> this <span>query</span>", perhaps using regular expressions I could find and extract values "Test" or "query", but in my case, I have potentially n such strings to extract. And since I can't define n columns in my select statement, that means I'm stuck. Is there anyway I could have a list of values (ideally separated by commas) of any text contained with span tags? In other words, if I ran this query, I would get "Test,query" as the value of spanlist: select <insert logic here> as spanlist from HtmlPages ...

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

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

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

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

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  • Ant database rebuild script, avoiding interactive prompting

    - by fras85
    Hi Guys. I'm writing an ant script to rebuild our database i.e. dropping everything and rebuilding from scratch. The problem our DBA adds a Y/N prompt before executing the rest of the script, and therefore we can't call this from an automated build process. Does anyone have any suggestions to circumvent the Y/N prompt? Obviously we could create seperate scripts, one for the DBA's and one for the automated build - but this requires maintaning both. We're running on Windows so it's not as easy as using sed to strip out the prompt...but i'm thinking something along those lines. Not sure if that's clear enough but hope you can help. Cheers.

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  • How can I perform this query between related tables without using UNION?

    - by jeremy
    Suppose I have two separate tables that I watch to query. Both of these tables has a relation with a third table. How can I query both tables with a single, non UNION based query? I want the result of the search to rank the results by comparing a field on each table. Here's a theoretical example. I have a User table. That User can have both CDs and books. I want to find all of that user's books and CDs with a single query matching a string ("awesome" in this example). A UNION based query might look like this: SELECT "book" AS model, name, ranking FROM book WHERE name LIKE 'Awesome%' UNION SELECT "cd" AS model, name, ranking FROM cd WHERE name LIKE 'Awesome%' ORDER BY ranking DESC How can I perform a query like this without the UNION? If I do a simple left join from User to Books and CDs, we end up with a total number of results equal to the number of matching cds timse the number of matching books. Is there a GROUP BY or some other way of writing the query to fix this?

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  • Linq to Sql: Update Entity throug a new Object

    - by Dänu
    Hey Guys I'd like to update an entity via linq, but since I edit the entity in a view after serializing it, I don't have direct access to the entity inside the data context. I could do it like this: entity.property1 = obj.property1; entity.property2 = obj.property2; ... thats not cool... not cool at all. Next thing I tried is to do it via .attach() like so: context.Table.attach(entity, obj); doesn't work either. So is there another option short of reflection?

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  • MySQL: Count occurrences of known (or enumerated) distinct values

    - by Eilidh
    After looking at how to count the occurrences of distinct values in a field, I am wondering how to count the occurrences of each distinct value if the distinct values are known (or enumerated). For example, if I have a simple table - TrafficLight Colour ------------ ------ 1 Red 2 Amber 3 Red 4 Red 5 Green 6 Green where one column (in this case Colour) has known (or enumerated) distinct values, how could I return the count for each colour as a separate value, rather than as an array, as in the linked example. To return an array with a count of each colour (using the same method as in the linked example), the query would be something like SELECT Colour COUNT(*) AS ColourCount FROM TrafficLights GROUP BY Colour, and return an array - Colour ColourCount ------ ----------- Red 3 Amber 1 Green 2 What I would like to do is to return the count for each Colour AS a separate total (e.g. RedCount). How can I do this?

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  • Best performance approach to history mechanism?

    - by Royi Namir
    We are going to create History Mechanism for our changes in DB (DART in pic) via Triggers. we have 600 tables. Each record that will be changed - the trigger will insert the deleted one into XXX. regarding to the XXX : option 1 : clone each table in "Dart" DB and each table now will have a "sister table" e.g. : Table1 will have Table1_History problems : we will have 1200 tables programmer can do mistakes by working on wrong tables... option 2 : make a new DB (DART_2005 in pic) and the history tables will be there option 3 : use linked server which stores the Db which will contain the history tables. question : 1) which option gives the best performance ( I guess 3 is not - but is it 1 or 2 or same ?) 2) Does option 2 is acting like "linked server" ( in queries we will need to select from both DB's...) 3) What is the best practice approach ?

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  • Ways to update a dependent table in the same MySQL transaction?

    - by codie
    I need to update two tables inside a single transaction. The individual queries look something like this: 1. INSERT INTO t1 (col1, col2) VALUES (val1, val2) ON DUPLICATE KEY UPDATE col2 = val2; If the above query causes an insert then I need to run the following statement on the second table: 2. INSERT INTO t2 (col1, col2) VALUES (val1, val2) ON DUPLICATE KEY UPDATE col2 = col2 + val2; otherwise, 3. UPDATE t2 SET col2 = col2 - old_val2 + val2 WHERE col1 = val1; -- old_val2 is the value of t1.col2 before it was updated Right now I run a SELECT on t1 first, to determine whether statement 1 will cause an insert or update on t1. Then I run statement 1 and either of 2 and 3 inside a transaction. What are the ways in which I can do all of these inside one transaction itself? The approach I was thinking of is the following: UPDATE t2, t1 set t2.col2 = t2.col2 - t1.col2 WHERE t1.col1 = t2.col2 and t1.col1 = val1; INSERT INTO t1 (col1, col2) VALUES (val1, val2) ON DUPLICATE KEY UPDATE col2 = val2; INSERT INTO t2, t1 (t2.col1, t2.col2) VALUES (t1.col1, t1.col2) ON DUPLICATE KEY UPDATE t2.col2 = t2.col2 + t1.col2 WHERE t1.col1 = t2.col2 and t1.col1 = val1; Unfortunately, there's no multi-table INSERT... ON DUPLICATE KEY UPDATE in MySQL 5.0. What else could I do?

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

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

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  • SSRS Dynamic Returning Dataset Collection Field in Expression

    - by Ray Clark
    I wrote a custom assembly to take a parameter value from the report and return a field from the dataset collection. My assembly returns the correct fields!name.value, but it shows me the string representation of it. How can I get it to resolve as the actual fields!name.value to display the actual data in the dataset? If I enter fields!name.value in manually it works fine showing me the value. If I resolve it with my custom code it display "fields!name.value" to me in the cell.

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  • Insert Stored Procedure, Using Asp.Net WebForm to Insert new [Customer]

    - by user2953815
    Can someone please help me create a stored procedure to insert a new customer from a web form. I am having difficulty making the state a drop down list for customer to pick a state from the list and having that inserted into the database. INSERT INTO Customer ( Cust_First, Cust_Middle, Cust_Last, Cust_Phone, Cust_Alt_Phone, Cust_Email, Add_Line1, Add_Line2, Add_Bill_Line1, Add_Bill_Line2, City, State_Prov_Name, Postal_Zip_Code, Country_ID ) VALUES ( @Cust_First, @Cust_Middle, @Cust_Last, @Cust_Phone, @Cust_Alt_Phone, @Cust_Email, @Add_Line1, @Add_Line2, @Add_Bill_Line1, @Add_Bill_Line2, @City, @State_Prov_Name, @Postal_Zip_Code, @Country_ID )"> <InsertParameters> <asp:Parameter Name="Cust_First" Type="String"></asp:Parameter> <asp:Parameter Name="Cust_Middle" Type="String"></asp:Parameter> <asp:Parameter Name="Cust_Last" Type="String"></asp:Parameter> <asp:Parameter Name="Cust_Phone" Type="String"></asp:Parameter> <asp:Parameter Name="Cust_Alt_Phone" Type="String"></asp:Parameter> <asp:Parameter Name="Cust_Email" Type="String"></asp:Parameter> <asp:Parameter Name="Add_Line1" Type="String"></asp:Parameter> <asp:Parameter Name="Add_Line2" Type="String"></asp:Parameter> <asp:Parameter Name="Add_Bill_Line1" Type="String"></asp:Parameter> <asp:Parameter Name="Add_Bill_Line2" Type="String"></asp:Parameter> <asp:Parameter Name="City" Type="String"></asp:Parameter> <asp:Parameter Name="Postal_Zip_Code" Type="String"></asp:Parameter> <asp:Parameter Name="Cust_ID" Type="Int32"></asp:Parameter> <asp:Parameter Name="State_Prov_Name" Type="String"></asp:Parameter> <asp:Parameter Name="Country_Name" Type="String"></asp:Parameter> </InsertParameters>

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  • Date and time Query - problem

    - by Gold
    hi i try to run this query: select * from WorkTbl where ((Tdate = '20100414' AND Ttime = '06:00') and (Tdate <= '20100415' AND Ttime <= '06:00')) i have this date: 14/04/2010 and time: 14:00 i cant see hem, how to fix the query ? thank's in advance

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  • Removing "Using temporary; Using filesort" from this MySQL select+join+group by query

    - by claytontstanley
    I have the following query: select t.Chunk as LeftChunk, t.ChunkHash as LeftChunkHash, q.Chunk as RightChunk, q.ChunkHash as RightChunkHash, count(t.ChunkHash) as ChunkCount from chunksubset as t join chunksubset as q on t.ID = q.ID group by LeftChunkHash, RightChunkHash And the following explain table: id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE subsets ref PRIMARY,IDIndex,SubsetIndex SubsetIndex 767 const 522014 "Using where; Using temporary; Using filesort" 1 SIMPLE subsets eq_ref PRIMARY,IDIndex,SubsetIndex PRIMARY 771 sotero.subsets.Id,const 1 "Using where; Using index" 1 SIMPLE c ref IDIndex IDIndex 4 sotero.subsets.Id 12 "Using where" 1 SIMPLE c ref IDIndex IDIndex 4 sotero.subsets.Id 12 note the "using temporary; using filesort". When this query is run, I quickly run out of RAM (presumably b/c of the temp table), and then the HDD kicks in, and the query slows to a halt. I thought it might be an index issue, so I started adding a few that sort of made sense: Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment chunks 0 PRIMARY 1 ChunkId A 17796190 NULL NULL BTREE chunks 1 ChunkHashIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 IDIndex 1 Id A 1483015 NULL NULL BTREE chunks 1 ChunkIndex 1 Chunk A 243783 NULL NULL BTREE chunks 1 ChunkTypeIndex 1 ChunkType A 2 NULL NULL BTREE chunks 1 chunkHashByChunkIDIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 chunkHashByChunkIDIndex 2 ChunkId A 17796190 NULL NULL BTREE chunks 1 chunkHashByChunkTypeIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 chunkHashByChunkTypeIndex 2 ChunkType A 261708 NULL NULL BTREE chunks 1 chunkHashByIDIndex 1 ChunkHash A 243783 NULL NULL BTREE chunks 1 chunkHashByIDIndex 2 Id A 17796190 NULL NULL BTREE But still using the temporary table. The db engine is MyISAM. How can I get rid of the using temporary; using filesort in this query? Just changing to InnoDB w/o explaining the underlying cause is not a particularly satisfying answer. Besides, if the solution is to just add the proper index, then that's much easier than migrating to another db engine.

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