Web Forms :: Tableadapter Doesn't Allow Null Integer Columns?
Mar 29, 2010
I have an sproc which selects data out of my table. The column can return integer or NULLs.
I get the 'failed to enable constraints error' when databinding. If I go to my tableadapter and select my column there is a NullValue property which has 'Throw Exception, Null, Empty'. If I try and unset the exception option it tells me only strings are allowed this. However the 'AllowDBNull' option is set to TRUE.
What is the alternative and will this be fixed in 2010?
I am creating a TableAdapter using corresponding wizard, with a GetDataByID() query. The select statement is like this:select * from books where ID = ?Thus books are filtered by ID. But in case a null is passed as a parameter, I want to select all records rather than none. Could you please tell me how I can do it?
I need to validate integer within a specified range for English and French culture. The integer contains group separator ("," in English culture or " " in French culture). It seems I can't do it with RangeValidator on my machine.
I just want to make sure the RangeValidator can't do this kind validation for Integer before I'm going to write my own control.
I just feel curious because RangeValidator can actually do this kind of validation for Currency!
I receive the error message below, I think because the database field in question is null (I realize I probably should not allow null values, but I can't even display the page to allow the user to enter a value---and I would prefer not to enter a default value in SQL).
How do I avoid this error message? If the column is null (and it is supposed to be an integer), do I need to change the value to something like "0" in the code behind---or is there any easier way to do this right in aspx page (see source of error message below)? Either way, I'm not sure how to do either (I can't get any such lines of code to work here). Object cannot be cast from DBNull to other types.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.InvalidCastException: Object cannot be cast from DBNull to other types.
STDNo nvarchar(6) //student number primary CID nvarchar(7) //course ID primary DNo int //Department Number primary H1 int allow null // Home work 1 H2 int allow null H3 int allow null H4 int allow null H5 int allow null Q1 int allow null //Quize 1 Q2 int allow null Q3 int allow null Q4 int allow null Q5 int allow null HE1 int allow null HE2 int allow null FExam int allow null // Final Exam
and stored procedure like this:
ALTER procedure [dbo].[AddMonthlyMarks] ( @STDNo nvarchar(6), @CID nvarchar(7), @Dno int =isnull, @H1 int, @H2 int,..........................
the Data key name of grid is STDNo the problem is that the instructor this month will add only homework1(h1) for specific student number or to all students and rest of home works and quezies will not entered (Null), to the next month he will enter home work 2 ,etc... i get an error and i think that the null values for others home works in grid make this error caution: in table i check allow null property,the data type is integer How i can convert this null values to integer?
I have a dataset.table which has some null values. am trying to trasform this using xslt to display like excel. If the value is null, then that node is ommitted by the xml. i tried deafulting the null values from the database itself and thats not generic. Handling null values is troublesome. I tried couple of methods to default null values by looping and thats not optimal solution. I used LINQ to handle null values but couldnt comeup with a neat solution. what am looking for is a generic optimal solution to handle these values.
I have two columns in my Gridview marked false for the visible property but which are clearly listed in the DataKeyNames that are still getting set to null in my database table on update.
The first one is a column MId# which is a type int. It starts as 0 but on edit is turned into null. The Second is RequireSKU which is also converted to null.
if a person does not select image in website in database null value go. when we retrieve data for that person i want if image is null then i want to show blank face image. for storing and retrieve image im using handler.ashx but not able to do the part that i have explained .
I am updating a gridview. Problem is that when I hide certain fields that I do not want the user to update, they lose their values ie. the data is wiped out in the field unless I show them on the grid and make them writeable. Is there a property I need to set for the field to retain the value when the grid is updated or is this in the sql statement?
I need to concatenate several columns of a table into a single value, then show that value in an asp dropdownlist. The SQL code I'm issuing is as follows:
SELECT UserID, CustomerNum, UserName + ' - ' + UserAddress + ',' + UserCity + ' ' + UserState AS UserInfo FROM Users WHERE (CustomerNum = @CustomerNum) ORDER BY UserName
I then set 'UserInfo' as the text field in the dropdownlist.This generally works, except occasionally one of the columns in the database is null (for example, UserState). When that happens, the entire concatenation is null, and I get an empty entry in the dropdownlist.
Is there something in SQLServer that will allow me to ignore those NULL results, or will I have to code something up in the DataBind event?
True) to update database row that returns null values from date and numeric columns,Whenever i try to update same row with null (or empty) values on both date and numeric columns, it results in sending '01-Jan-0001' for date column and 0 for numeric column. I want the user to have the options of null or corresponding values for the update.
I have the below stored procedure witch has an error I cann't figure out.
What I want: Gets rankOrder. If rankOrder doesn't have a value (= null) the @num should be insertet as 1 as value. If there is a row and a rankOrder is should set the @num to insert the value + 1. The last one works perfect. But when the row I select is emty = null value the value is set to null in the insert command.
I'm currently stuck with a problem with MVC2 RC and validation on a dropdownlist :
I have a page with some fields and a dropdownlist. The dropdownlist is not a mandatory field so I would like to save a null value into my property.
Unfortunately, I can't validate my page with a null selected value, because when I look into the modelstate just on the first line of my action, I've already an error telling me I must choose an item.
Is it normal working of dropdownlist validation or is it a bug ?
I'm trying to make filters on gridview. Gridview is bound to SqlDataSourceControl.
The problem is when there is NULL value in DB.
Parameters
Code:
[code]....
Select Statement
Code:
SELECT Name, Phone, email FROM suragch WHERE (firstname LIKE @firstname + '%') AND (phone LIKE @phone + '%') AND (email LIKE @email + '%')
Above example works fine if there is no NULL.
When users want to find email they leave phone field empty and enters the firstname. But my example doesn't displaying email of given user if phone is NULL in db.
I've created a WCF Service that Performs Insert User, What it does is, it'l get user name, age,gender,address,phone no and inserts these values into SQL database.
Problem is :
These things are working fine, if i give all the values in the WCF Test Client, It's Not working when i din't enter value for Address and click "Invoke" Button, It's throwing an Exception Procedure or Function "Insert_User" Expects
ADDRESS' Which was not supplied. I've created the SQL table Which allow Null Values for Address.
I've did the same Operaion in WebService also, there it's working fine, if i din't enter any value for tha Allow Null Colums, it's accepting the Null value and inserting into Database.
Why this Problem comes in WCF Test client, Guide me to Get rid of this Problem.
In reference to this question that I just asked, [URL] it appears that for some reason, an empty text box's value is not being fed to SQL Server as NULL, as it ought to be.
I have a typical gridview/formview master control setup. When I try to update or insert I don't get any errors but it also doesn't work. When I try to insert data all I get are null values and when I update, none of the values are updated. The formview looks like its working, but just doesn't. The primary key is an identity and it auto-increments by one.
I have a webpage that displays the results of a query on a table. The resulting list is sorted by town:
New York
Hyatt Regency Waldorf Astoria Paris
Hotel du Louvre Hotel Le Meurice
I've been asked to add to this list another sublist of nearby hotels. The intended result is:
New York
Hyatt Regency Waldorf Astoria nearby hotels:
hotel 1 hotel 2
Paris
Hotel du Louvre Hotel Le Meurice nearby hotels:
hotel 3 hotel 4
I've got a TableAdapter set up in VS2010 so that I can query the table for nearby hotels with "@town" as the parameter. So at the end of each list of hotels in a town, I need to display the results of this query.
If the query turns up no records (no nearby hotels), I don't want to display anything. If it turns up 1 or more records, I want to display the list of nearby hotels.
I am trying to set up a conditional "if" statement that checks to see if any records returned but am getting an error when I try to build:
Error 3 'Maine_Innkeeper_Site_2010.App_Code.DataAccessLayer.MaineInnsDatasetTableAdapters.membersTableAdapter.GetNearbyProperties(string)' is a 'method', which is not valid in the given context E:Ed dataclientsMaine InnkeepersMIA website 2010Maine Innkeeper Site 2010lodging-search-output.aspx.cs 49 49 Maine Innkeeper Site 2010 [Code]....
I have a TableAdapter that consists of an SQL SELECT query.
Need to create an "if" statement that checks to see if the query returned any records.
Tried "HasRows" but Visual Studio 2010 says: Error 2 'Maine_Innkeeper_Site_2010.App_Code.DataAccessLayer.MaineInnsDataset.membersDataTable' does not contain a definition for 'HasRows' and no extension method 'HasRows' accepting a first argument of type 'Maine_Innkeeper_Site_2010.App_Code.DataAccessLayer.MaineInnsDataset.membersDataTable' could be found (are you missing a using directive or an assembly reference?) E:Ed dataclientsMaine InnkeepersMIA website 2010Maine Innkeeper Site 2010lodging-search-output.aspx.cs 49 83 Maine Innkeeper Site 2010
What's the proper way to check if HasRows is wrong?
