I have a situation where a query returns ~20 columns, but at any given execution only 5 of the 20 will have non-NULL values. The remaining 15 will contain null for every row in those columns.
I need to figure out which of the 5 columns have values. I am using a SqlCommand. How would I best approach figuring out these 5 columns?
i have DateFrom and DateTo columns in tblLOgs.if they both are same then select only DateFrom else both selects.my procedure is ....do modification in them
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I am working on a legacy application. It uses custom MVC framework and Windows Communication Framework service to bridge the Presentation layer with the rest of the application (i'll call this AppServer).
Every Entity in the AppServer inherits from BaseEntity which contains the method:
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As you can see:
if the personObject was not null, but the ContactAddress was, [which is exactly what happens in the construction of a PersonObject in the event that no contact details are provided (hence they are not present in the HashTable and dont get created)] then the code will fail with a null reference exception.
SO:
Is there a fundamental flaw in the way that objects are getting created? It would be easy to point the finger in this direction, however, im sure there must have been some reason for the original architect to choose not to instantiate an empty ContactAddress object every time a Person object is referenced - EG if in a particular Presention->AppServer Request/Response cycle we only want a person's login details - we wouldn't care about the ContactDetails.
FINALLY MY QUESTION:
Is there a clean way to check for null objects within an aggregation, without doing something like:
if(Parent!=null)
if(Parent.child!= null)
if(Parent.child.child != null)
It just looks messy and it seems such a common problem, im sure there would be a better way of doing things.
I have a Listview with a LinqDataSource. I am allocating a resoure called Bladder Scanners to clinicians on the day selected. The field in the database, 'Allocated_Bladder_Scanner_Id', allows nulls. The 'nullable' property of the field in the dbml is set to allow nulls.In the edit template, I have an unbound dropdownlist (drpBladderScannerDropdown) with an 'empty string' item added to cater for nulls, and
AppendDataBoundItems="true".In order to show only bladder scanners which have not yet been allocated on the selected day, I am databinding the dropdownlist to a dictionary of unallocated bladder scanners in the ItemDataBound event. I then add the currently selected bladder scanner as a listitem and set it as the selected item. So far, so good, all works well. However, if the clinician has a bladder scanner currently allocated, and then the user elects to not allocate the clinician a bladder scanner on that day by selecting 'Nothing' from the dropdownlist, the LinqDataSource fails to update the field. It does not throw an exception, it just doesn't set the field to nulls. In ItemUpdating I have the following code:
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I have two columns first name and last name , that have duplicates, how can i remove the duplicates and only leave the distinct members intact?
View 6 RepliesI have a GridView and check box in one of the columns.what i need to do is, if the checkbox is checked i need to replace it with a Tick Mark image instead of checkbox, otherwise leave the column blank.
View 13 RepliesIm developing an ASP Web application and have a Gridview which I have set as follows:-
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At this point alls good.
I have a field in the selected table that returns an integer which relates to a Table on a Seperate Database.
Is it possible, when the grid is being filled to check a fields value and set anothers columns value depending on the vale?
ie First Row Column 1 value is 1 so set Column 2 to "Sunny"
Second Row Column 1 value is 2 so set Column 2 to "Cloudy"
I have a datasource, which includes many columns, idealy, I need use a gridview to show:
1) first 3 columns: template fields, these fields depends on values in some columns of datasource. I use template fields, hard coded. works fine.
2) the other columns. This is I do not know how to do it. In the data source, there are about 10-20 columns data, each time, the # of columns of the data varies. idealy, I need show each of them as a seperated column in gridview. The entire data source may have 30 columns, but some of them are used in 1), and I only want show these 10-20 columns in gridview. Some columns in data source, I may not use them at all. is there a way to do this? or have to seperate them as a detail view style UI?
how to sort a datatable (dataview) so that the second column is ascending but nulls are last.
I'm trying to do the following Date1 ASC, DATE2 ASC (but if DATE2 is null it is last in this Date1 group)
Note: Date1 can never be null so a Date2 that is null should still be grouped in with its Date1.
I'm looking to find some command or control that will change fields in a detailsview insert a 0 if there was no data inserted into them. Some example code from my boundfield is:
<asp:BoundField DataField="Assignment_Travel_Time"
I have been struggling with an issue with the Detailsview that I'm using only sending null values to my sqldatasource update. I have seen people on the forums with this problem before but none with my specifics. Essentially, I'm creating a master/details scenario but using ajax updatepanels. A Gridview holds the master records and upon selection of that record the Detailsview is populated and brought up in a modal box. This works fine to display the data in the Detailsview. But upon update all nulls are sent back. I've evaluated the NewValues collection in the Detailsview OnItemUpdating event, and see all nulls. I read a posthere that talks about the KB article KB941155; which states a problem with .NET not being able to find a bound control in template situations:http://support.microsoft.com/kb/941155I wasn't sure if this applied to me since I am using Master pages. A couple of other notes. I am using BoundFields in my Detailsview, as well as a sqldatasource with a stored procedure updatecommandtype. The DataKeyNames are being set correctly as well.
View 6 RepliesMy filter Expression was working fine with filtering by Control Parameters.When I added the Phone Parameter it went nuts - with the Phone Parameter the GridView just Comes out blank upon loading the page (without it would show Select * from Individuals)Is it because the phone field is populated with numbers? Don't get it.... In the SQL server the 'phone' field is set to 'varchar(30)' and nulls are allowed.here is my code:
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I'm trying to add these 4 co,umns to the table as bit type woth a defaut of FALSE. What am I doing wrong here? I get a syntax error near (
create PROCEDURE [dbo].[AddADIFields]
AS
ALTER TABLE dbo.tblTESTS ADD (AI1 Bit 0,AI2 Bit 0,AI3 Bit 0,AI4 Bit 0)
I am SELECTING two columns:
SELECT ([FirstName] + [LastName]) AS [FullName], UserID WHERE CustomerID = @CustomerID
I would just like to know if there is a way to add a space between the two columns in the select statement.
This SqlDataSource Binds to a DropDownList so TextValue = "FullName" and DataValue = "UserId"
but of course, the way it is now the fullname is all one word.
I want to create a constraint for 3 columns (A B and C) where if columns B or C are not null, then A cannot be null. And vice versa (i.e., if A is not null, then either B cannot be null, or C cannot be null).I am not very well versed in SQL and would like to know what is the best way to achieve this (e.,g Check constraint, stored procedure, function, trigger)? I'm leaning towards trigger but I'm not 100% sure if that's right nor of how to implement it.
View 3 RepliesI want to know that how many tables we can have in database and what is the maximum no. of columns.I also want to know the maximum size for each datatype.
View 3 RepliesI need to join some tables to get the matching records. I often have to ask around to see how certain tables could be joined. Is there any way to query the information schema or some thing else to see what columns/values match in certain tables in order to figure out how tables should be joined.
View 4 RepliesI have a DataSet that I bind to a GridView control. I want to only show certain columns from the DataSet. Should I do that with my SQL query (that I use to populate my DataSet) or somehow with a DataView?
View 7 Repliesis there a SQL statment i could write that would sum each column and allow me to then access each sum individually
i.e
Dim objCmd As New OleDb.OleDbCommand("SELECT SUM(expression) FROM orderForm WHERE OrderDate=@OrderDate", objConn)
is there anything i can replace expression with such that all the columns in orderForm could be summed and returned as one record
or is there a way to replace expression with something that would allow me to just keep changing the paramater so i could continuously reexectute the same command w/o having to create a new command for each column
this is my sample script
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after execute this script which returns a column name "XML_F52E2B61-18A1...." can I change this column name?like this
select EMPNO AS EmployeeName -- we can use AS to change column name
from EMPLOYEE
I am returning a dataset from a method and trying to set one of the columns as Primary Key.
CategoryList.Tables[0].PrimaryKey = new DataColumn[] { CategoryList.Tables[0].Columns["CategoryNodeId"] };
Interestingly it gives me this error at run-time, These columns don't currently have unique values.
Now I perfectly know why this error should error, but there are no duplicate keys in this data column. I broke the code in between and bound the dataset to gridview to check if this column contains any duplicates and this is not the case. Here is the result set underneath. Have a look at the first column 'CategoryNodeId'.
CategoryNodeId
CategoryId
Name
ParentCategoryNodeId [code]...
unable to find a work around for now.
If I have a linq statement like:
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There may be a lot of data in the Blogs table. What if all I wanted was say BlogID, BlogTitle and BlogAuthor and nothing else, is there a way to do this in an effort to make the sql more efficent?
Along the same lines in my DataContext (.dbml) file I added some associations between some of my tables. This makes coding nice when I do a linq statement that will join those tables automatically for me but my concern is does it do that everytime, thus making all my linq quieries inefficient?
I use MySQL database and SqlDataSource controls. I generate update and insert queries in my code behind.how I can get a list of columns from the SqlDataSource control?
View 2 RepliesI have a table like this..
---------------------------------------------------
ItemID ItemName Qty CenterID
---------------------------------------------------
1 X 10 52
1 X 6 53
1 X 4 57
2 y 6 58
I SHOULD convert the abouve table like this..
ItemID ItemName Qty CenterA centerB CenterC CenterD
---------------------------------------------------
1 X 20 10 6 4 0
2 Y 6 0 0 0 6
i dont why its happening.Below is my table
Create table workorder
(
WoID nvarchar(10),
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