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• Show/Hide GridView Header in ListView

  - by Chris

  I have a ListView in WPF, and I want to hide the headers for the ListView when the List the ItemsSource is bound to is null, and display the headers when the ItemsSource is not null and has at least 1 item in the collection. I have found the code online to hide the ListView headers like this: <Window.Resources> <Style x:Key="HideListViewHeaders" TargetType="{x:Type GridViewColumnHeader}"> <Setter Property="Visibility" Value="Collapsed" /> </Style> </Window.Resources> Thanks for any help!

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• How to write a CASE WHEN statement with multiple DATEDIFF variables

  - by Anne C

  I need to calculate the difference between two dates (facility_start_date, facility_end_date) for a report in Reporting Services in SQL 2005. If the facility_end_date is null then it needs to use the report parameter @EndDate in the calculation. However if the facility_end_date is greater than the parameter @EndDate, then it also needs to use the paramenter @EndDate. The code below works fine except that if the facility_end_date is greater than the parameter @EndDate it is still calculating between the facility_start_date and facility_end_date, rather than between the facility_start_date and @EndDate. Any help would be appreciated. CASE WHEN facility_start_date > facility_end_date THEN NULL WHEN DATEPART(day , facility_start_date) > DATEPART(day , facility_end_date) THEN DATEDIFF(d , facility_start_date , ISNULL(facility_end_date , @EndDate)) - 1 WHEN DATEPART(day , .facility_end_date) > DATEPART(day , @EndDate) THEN DATEDIFF(d , facility_start_date , @EndDate) - 1 ELSE DATEDIFF(d , facility_start_date , ISNULL facility_end_date , @EndDate)) END

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• Data structure name: combination array/linked list

  - by me_and

  I have come up with a data structure that combines some of the advantages of linked lists with some of the advantages of fixed-size arrays. It seems very obvious to me, and so I'd expect someone to have thought of it and named it already. Does anyone know what this is called: Take a small fixed-size array. If the number of elements you want to put in your array is greater than the size of the array, add a new array and whatever pointers you like between the old and the new. Thus you have: Static array ————————————————————————— |1|2|3|4|5|6|7|8|9|a|b|c| ————————————————————————— Linked list ———— ———— ———— ———— ———— |1|*->|2|*->|3|*->|4|*->|5|*->NULL ———— ———— ———— ———— ———— My thing: ———————————— ———————————— |1|2|3|4|5|*->|6|7|8|9|a|*->NULL ———————————— ————————————

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• Can I use a single instance of a delegate to start multiple Asynchronous Requests?

  - by RobV

  Just wondered if someone could clarify the use of BeginInvoke on an instance of some delegate when you want to make multiple asynchronous calls since the MSDN documentation doesn't really cover/mention this at all. What I want to do is something like the following: MyDelegate d = new MyDelegate(this.TargetMethod); List<IAsyncResult> results = new List<IAsyncResult>(); //Start multiple asynchronous calls for (int i = 0; i < 4; i++) { results.Add(d.BeginInvoke(someParams, null, null)); } //Wait for all my calls to finish WaitHandle.WaitAll(results.Select(r => r.AsyncWaitHandle).ToArray()); //Process the Results The question is can I do this with one instance of the delegate or do I need an instance of the delegate for each individual call? Given that EndInvoke() takes an IAsyncResult as a parameter I would assume that the former is correct but I can't see anything in the documentation to indicate either way.

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• Execute query stored in variable in a very specific way

  - by niao

  Greetings, I have a problem as follows: I have an SQL variable declared: DECLARE @myVariable nvarchar(max) a third party library set a value for this variable. To simplify, lets say that the value is as follows: SET @myVariable = 'Select ROWGUID from MySampleTable' Now, I want to execute the following query: SELECT ROWGUID FROM myTable WHERE ROWGUID in (exec sp_executesql @myVariable ) However, the above statement does not work because it returns an error telling me that I can't execute stored procedure in that way. I made a workaround and this is what I wrote: create table #temptable (ID uniqueidentifier null) if(@myVariable is not null AND @myVariable !='') insert into #temptable exec sp_executesql @myVariable SELECT ROWGUID FROM myTable WHERE ROWGUID in (select * from #temptable) DROP TABLE #temptable This works fine.However I don't think it is a good idea to use temporary table. How can I achieve the same result without necessity of creating temporary tables? I am using SQL SERVER 2005

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• Cron job execute backup.bash

  - by leejava

  Dear all, I wish to let cron executes backup.bash, but when I try to create cron as below: */1 * * * * /var/www/mango_gis/delete_snapshot.bash /dev/null It didn't execute my script at all. Here is my script as below: #!/bin/bash get() { local pos=$1 shift eval 'echo ${'$pos'}'; } length(){ echo $#; } find_snapshots() { echo $(ec2-describe-snapshots | xargs -n1 basename); } snapshots=$(find_snapshots) len=$(length $snapshots) row_count=$(($len/6)) if(($row_count 6)); then delete_count=$(($row_count-6)) for (( i=1; i<=$delete_count; i++ )); do ec2-delete-snapshot $(echo $(get $((2+$((6*$(($i-1)))))) $snapshots)) /dev/null done fi Please advise... Leakhina

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• problem with sql statement using vb.net

  - by newBie

  hi i got some problem i got this 3 line statement: Dim infoID As Integer = objCommand1.ExecuteScalar() Dim strSQL2 As String = "insert into feedBackHotel (infoID, feedBackView) values(" + infoID + ",'" + FeedBack + "')" Dim objCommand2 As New SqlCommand(strSQL2, conn) objCommand2.ExecuteNonQuery() the problem here is..the strSQL2 can capture the infoID from previous statement, but it didnt insert into the database. it will pop out this error "Conversion from string "insert into feedBackHotel (infoI" to type 'Double' is not valid." in both table related, use same data type (int) but for the feedBackHotel's infoID i allow it to be null..bcoz if i make it not null, it will show another error.. im using vb.net ..can anyone help?

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• Initializing a value through a Session variable

  - by William Calleja

  I need to Initialize a value in a Javascript by using a c# literal that makes reference to a Session Variable. I am using the following code <script type="text/javascript" language="javascript" > var myIndex = <%= !((Session["myIndex"]).Equals(null)||(Session["myIndex"]).Equals("")) ? Session["backgroundIndex"] : "1" %>; However the code above is giving me a classic Object reference not set to an instance of an object. error. Why? Shouldn't (Session["myIndex"]).Equals(null) capture this particular error?

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• How to restrict this function from execution in android? Please help

  - by andyfan

  This code is present in one of this activity. I want to restrict addJoke() function from executing if the String variable new_joke is null, has no text or contains just spaces. Here is code protected void initAddJokeListeners() { // TODO m_vwJokeButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View view) { //Implement code to add a new joke here... String new_joke=m_vwJokeEditText.getText().toString(); if(new_joke!=null&&new_joke!=""&&new_joke!=" ") { addJoke(new_joke); } } }); } I don't know why addJoke() function is getting executed even I don't enter any text in EditText field. Please help.

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• pthread_exit return value

  - by Manty

  This is surprising for me. void * thread_func(void *arg) { pthread_exit(&ret); } int main(void) { pthread_t thr; int *exit_status; pthread_create(&thr, NULL, thread_func, NULL); sleep(2); pthread_join(thr, (void **)&exit_status); printf("value of exit status - %d\n", *exit_status); ret = 20; pthread_join(thr, (void **)&exit_status); printf("value of exit status - %d\n", *exit_status); return 0; } The output is value of exit status - 50 value of exit status - 20 I was expecting both the times the exit_status would be the actual exit value(50 in my case) of the thread. Instead it is just returning the value of the global variable which I used for pthread_exit. Is it not a bug?

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• How can I fake sql data while preserving statements without commenting my server-side code?

  - by Fedor

  I have to use hardcoded values for certain fields because at this moment we don't have access to the real data. When we do get access, I don't want to go through a lot of work uncommenting. Is it possible to keep this statement the way it is, except use '25' as the alias for ratecode? IF(special.ratecode IS NULL, br.ratecode, special.ratecode) AS ratecode, I have about 8 or so IF statements similar to this and I'm just too lazy ( even with vim ) to re-append while commenting out each if statement line by line. I would have to do this: $sql = 'SELECT u.*,'; // IF ( special.ratecode IS NULL, br.ratecode, special.ratecode) AS ratecode $sql.= '25 AS ratecode';

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• Insert into select and update in single query

  - by Ossi

  I have 4 tables: tempTBL, linksTBL and categoryTBL, extra on my tempTBL I have: ID, name, url, cat, isinserted columns on my linksTBL I have: ID, name, alias columns on my categoryTBL I have: cl_id, link_id,cat_id on my extraTBL I have: id, link_id, value How do I do a single query to select from tempTBL all items where isinsrted = 0 then insert them to linksTBL and for each record inserted, pickup ID (which is primary) and then insert that ID to categoryTBL with cat_id = 88. after that insert extraTBL ID for link_id and url for value. I know this is so confusing, put I'll post this anyhow... This is what I have so far: INSERT IGNORE INTO linksTBL (link_id,link_name,alias) VALUES(NULL,'tex2','hello'); # generate ID by inserting NULL INSERT INTO categoryTBL (link_id,cat_id) VALUES(LAST_INSERT_ID(),'88'); # use ID in second table I would like to add here somewhere that it only selects items where isinserted = 0 and iserts those records, and onse inserted, will change isinserted to 1, so when next time it runs, it will not add them again.

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• Dynamically set the result of a TSQL query using CASE WHEN

  - by Name.IsNullOrEmpty

  SELECT MyTable.Name,(SELECT CASE WHEN ISNULL(SUM(TotalDays), 0) <= 0 THEN 0 ELSE SUM(TotalDays) END AS Total FROM Application AS Applications WHERE (ID = MyTable.id)) - MIN(Assignments) AS Excesses FROM MyTable The above TSQL statement is a subquery in a main query. When i run it, if TotalDays is NULL or <=0, then Total is set to 0 (zero). What i would like to do here is to set the result of the whole query(Excesses) to 0. I want (Excesses) which is the result of Total - Min(Assignments) to be set to 0 if its NULL or <=0. I want the CASE WHEN to apply to the whole query but am struggling to get it right.

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• How to read output of android process command

  - by kevdliu

  I am trying to get the output of android shell command 'getprop' with java since getprop() always returns null no matter what. I tried this from developer.android.com: Process process = null; try { process = new ProcessBuilder() .command("/system/bin/getprop", "build.version") .redirectErrorStream(true) .start(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } InputStream in = process.getInputStream(); //String prop = in.toString(); System.out.println(in); process.destroy(); However what is printed is not the output but a bunch of characters and numbers (dont have the exact output right now). How can i get the output of the process? Thanks!

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• what is wrong with my create table SQL?

  - by George2

  Hello everyone, I am using SQL Server 2008 management studio to execute the following SQL statements, and here is the related error message from SQL Server management studio. Any ideas what is wrong? SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO Create TABLE [dbo].[BatchStatus]( [BatchID] [uniqueidentifier] NOT NULL CONSTRAINT [PK_BatchStatus_ID], [BatchStatus] [int] NULL, CONSTRAINT [PK_BatchStatus_ID] PRIMARY KEY CLUSTERED ( [BatchID] ASC )WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY] ) ON [PRIMARY] GO Msg 102, Level 15, State 1, Line 3 Incorrect syntax near ','. Msg 319, Level 15, State 1, Line 8 Incorrect syntax near the keyword 'with'. If this statement is a common table expression, an xmlnamespaces clause or a change tracking context clause, the previous statement must be terminated with a semicolon. thanks in advance, George

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• Is there a way to have a bit bucket pointer? (C/C++)

  - by Crazy Chenz

  Is there a way to have a bit bucket pointer? A lot of IO (specifically input related) system calls return data to a buffer of a specific size. Is there a trick or way to make a sorta bit bucket pointer, so I can accept any amount of data that will be thrown away. Doing something like "char tmp[INT_MAX]" is crazy. The behavior I am looking for is something like /dev/null, only in a pointer world. Not to hopeful on this.... just curious. Thanks, Chenz UPDATE: Perhaps mmap-ing /dev/null. Forgot about that when I asked the question.

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• Resolve property at runtime. C#

  - by user1031381

  I have some class which have some code public IEnumerable<TypeOne> TypeOne { get { if (db != null) { var col = db.Select<TypeOne>(); if (col.Count > 0) return col; } return db2.TypeOne; } } public IEnumerable<TypeTwo> TypeTwo { get { if (db != null) { var col = db.Select<TypeTwo>(); if (col.Count > 0) return col; } return db2.TypeTwo; } } So as You can see there is a lot of duplicated Code and there are same property name and item type of enumerable. I want to call some property of object like "obj.MyProp". And MyProp must be resolved at runtime with some generic or non-generic method. Is it possible?

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• Getting a query to index seek (rather than scan)

  - by PaulB

  Running the following query (SQL Server 2000) the execution plan shows that it used an index seek and Profiler shows it's doing 71 reads with a duration of 0. select top 1 id from table where name = '0010000546163' order by id desc Contrast that with the following with uses an index scan with 8500 reads and a duration of about a second. declare @p varchar(20) select @p = '0010000546163' select top 1 id from table where name = @p order by id desc Why is the execution plan different? Is there a way to change the second method to seek? thanks EDIT Table looks like CREATE TABLE [table] ( [Id] [int] IDENTITY (1, 1) NOT NULL , [Name] [varchar] (13) COLLATE Latin1_General_CI_AS NOT NULL) Id is primary clustered key There is a non-unique index on Name and a unique composite index on id/name There are other columns - left them out for brevity

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• How to generate JSON object on client side and send it to server?

  - by EugeneS

  I have ExtJS based application. I have compound object on the server side, and have ExtJS window with few tabs for editing different parts of this one object. For example: I Have Compound object "Car" public class Car { public string Name; public string Color; public List Wheels; public List Doors; } And on my ExtJS window i have tabs ("General Info", "Wheels", "Doors") for editing different parts of this object. So what i want: When i want to create a new car i want to generate JSON configuration for my class "Car" like {Name:null; Color:null; Wheels:[]; Doors:[]} then sent it to the client, fill it on the client (without callbacks to server) and after user finishes creating his Car object (he added wheels, doors, set name and color) and press save, I want to sent this filled(generated) JSON object to server and save it to DB. Is it possible? Thanks

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• SQL JOIN with two or more tables as output - most efficient way?

  - by littlegreen

  I have an SQL query that executes a LEFT JOIN on another table, then outputs all results that could be coupled into a designated table. I then have a second SQL query that executes the LEFT JOIN again, then outputs the results that could not be coupled to a designated table. In code, this is something like: INSERT INTO coupledrecords SELECT b.col1, b.col2... s.col1, s.col2... FROM bigtable AS b LEFT JOIN smallertable AS s ON criterium WHERE s.col1 IS NOT NULL INSERT INTO notcoupledrecords SELECT b.col1, b.col2... bigtable AS b LEFT JOIN smallertable AS s ON criterium WHERE s.col1 IS NULL My question: I now have to execute the JOIN two times, in order to achieve what I want. I have a feeling that this is twice as slow as it could be. Is this true, and if yes, is there a way to do it more efficiently?

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• Why did this code still work?

  - by bstullkid

  Some old code that I just came across: MLIST * new_mlist_link() { MLIST *new_link = (MLIST * ) malloc(sizeof(MLIST)); new_link->next = NULL; new_link->mapi = NULL; new_link->result = 0; } This was being called to build a linked list, however I noticed there is no statement: return new_link; Even without the return statement there, the list still got built properly. Why did this happen? EDT: Platform: Mandriva 2009 64bit Linux 2.6.24.7-server GCC 4.2.3-6mnb1

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• Send a String[] ArrayList over Socket connection

  - by Duncan Palmer

  So i'm trying to send a String[] Array/List over an open socket connection. I currently have this code: Sending: public void sendData() { try { OutputStream socketStream = socket.getOutputStream(); ObjectOutputStream objectOutput = new ObjectOutputStream(socketStream); objectOutput.writeObject(new String[] {"Test", "Test2", "Test3"}); objectOutput.close(); socketStream.close(); } catch (Exception e) { System.out.println(e.toString()); } } Recieving: public Object readData() { try { InputStream socketStream = socket.getInputStream(); ObjectInputStream objectInput = new ObjectInputStream(new GZIPInputStream(socketStream)); Object a = objectInput.readObject(); return a; } catch(Exception e) { return null; } } After I have recieved the String array/list on the other end I want to be able to iterate through it like I would do normally so I can get the values. My current code doesn't seem to works as it returns null as the value. is this possible?

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• How can I filter out the "My Computer"-option in a SWT DirectoryDialog?

  - by Superfisi

  Hello *, in our Eclipse RCP application running on Windows XP we use a DirectoryDialog, in which the user should... ahmm... choose a directory! :D The problem is: If the user selects the "My Computer"-option (in German Windows "Arbeitsplatz") the Dialog returns null. The DirectoryDialog provides a method setFilterPath(String path) in which I put the File.pathSeparatorChar (to remain OS-independant). My suggestion was that if there has to be a file separator in the directory the "My Computer"-option would be ignored cause it is null - for example the "OK"-button would be greyed out or sth. like that... but it is also valid to klick "OK". Any suggestions from your side? :D Thanks in advance! Alex

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• beginner's question about CSS

  - by Nitesh Panchal

  Hello, I am creating a website and i want to allow personalization to individual users upto some extent like changing font family, background color etc. The problem with this is that, my default css file that i load has already default classes for everything. Now when i fetch the background color from my database, then if there is null value for background color then default css class of mystylesheet.css should be loaded and if the value is not null, then i want to override this with my default css. How is it possible? Thanks in advance :)

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• C# background worker and timer loop

  - by Mike

  This is my first attempt of a Timer, if someone could help me out where I am going wrong it would be awesome. I'm trying to use a while loop where if the timer hits 30 seconds try to loop it again. private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) { System.Windows.Forms.Timer my_timer = new System.Windows.Forms.Timer(); my_timer = null; //int restartticker = 30000; while (true) { my_timer.Start(); if (my_timer.Equals(30000)) { watcherprocess1(); } my_timer = null; } } Object reference not set to an instance of an object. my_timer.Start();

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