DataSource Controls :: How To Handle Null Value Between Sql And C#
Feb 3, 2010
I need to retrive a value from a column of a table per stored proc. This is usually an integer, but also can be null. I get this value and store it in a session variable.
Later, I need to pass this same session variable to another stored proc.
Session["myVariable"] = ds.tables[0].rows[0][1]; // this can be null or an integer
somewhere else in the project, I need to pass it to another stored proc exactly as received.
I get a recordset returned from DB and try to load it. However sometimes field "LastRun" may be empty (NULL). when i have this it compiles fine but errors out when value is null m_LastRun = Convert.ToDateTime(r["LastRun"]); when I take out Convert.ToDateTime it doesn't even compile.
I have a query that averages data in 15 minute increments that I display in a chart using Microsoft Chart Controls. Everything works fine except when there is no data for a 15 minute increment. How do I get the chart to show just the empty time slot?
I've got a detailsview control on a page. The table that it interacts with has a DateTime column in it. This column is nullable, and a lot of the records have null for that value. In the EditItemTemplate I've got a calendar control. When I try to put the DetailsView into edit mode, I get the following error message:
System.InvalidCastException was unhandled by user code Message=Specified cast is not valid. Source=App_Web_srpmlyjd StackTrace: at ASP.entries_aspx.__DataBinding__control44(Object sender, EventArgs e) in c:inetpubwwwrootMediaLibraryEntries.aspx:line 103 at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding) at System.Web.UI.Control.DataBindChildren()
I am convinced that the problem is the null values in the DateTime column of the table. I've done some web searches on this, and some have suggested placing some dummy values into that column, but that seems more like a kludge, rather than a solution. How do I keep nulls in the table, and yet not have that preceeding error come up when a user tries to edit the selected record?
for eg i hav a datetime field called Completion date which temporarily has a null value and when i display the records using a gridview it displays a default date...how do i get rid of this default date.the completion Date gets entered at a later stage in the application following which the gridview should show this date....but initially it shouldn't show anything
What if a user hits my site with [URL]t rather than [URL] In other words, they do not specify a value for {id}. If they do not, I want to display a nice "Not Found" page, since they did not give an ID.Is there a more standard MVC framework way of handling this, rather than the code I presently use (see below), where I test accept a nullable int? and then for null? Surely there is a smoother way to handle this.
I have a problem while checking a hashtable value. In the code below I am storing 60 values in the hashtable "hash". One of the values is (or can be) Null. I am checking each entry against its corresponding entry in hashtable "hash1", to see if they match each other. If they don't match I want to check if the value in "hash" is Null, but I can't catch it - it's falling through the 'else' part). How can I overcome this problem?
I have asp.net form with C#, where is I am taking user information to insert in the database as usual by using Linq. well. Where as I am taking Date of birth also from the user, but if user skip to fill date text box from ui, then I am getting date like '01/01/0001' something like this, which certainly database security would not allow to store it.
So I need to check somewhere in my code that it is null or in this (above given) format. If it is null or in format '01/01/0001' then what exactly I have to do? I don't have any default value for dates.
So what is the standard way to handle if date is null (but not mandatory). So many times I found myself in trap while handling null for various types.
In the detailsview, I set a edit item template (a bounded dropdownlist control). But in database there are some data not set to a value (null). After clicking edit button in detailsview control I get the error about the value problem (Because after populating the dropdownlist, there is no item as null in it. )How to set dropdownlist selected index when the data is "null"?
I'm using a custom ashx HttpHandler to retrieve gif images from a database and show it on a website - when the image exists, it works great.
However, there are cases when the image will not exist, and I'd like to have the html table holding the image to become invisible so the "image not found" icon is not shown.
here is my code for selectiong some records from db table
string strSql = "select * from mtblNBD where SentTo=@SentTo and InternalStatus Is NULL order by DeadLine desc"; SqlCommand com = new SqlCommand(strSql, con); com.Parameters.Add("@SentTo", SqlDbType.NVarChar, 50).Value = (string)Session["uname"];
here I am using parameters for SenTo field but not for NULL so it is ok... or should I use parameters for this field where value is NULL , if yes then how can I use parameter for this
I have page that has a datasource. The datasource executes a stored procedure and returns results. If the result is NULL, I'd like to forward the user to an error page. How would I accomplish this with ASP.NET and C#?
I am using this stored procedure with pivot.If i dont have data i am getting null with this stored procedure.Can u tell me how to handle null.below query is pivot.
I have a class with properties for stuff like FileNumber, OpenedDate, ClosedDate etc.When I Initialise the class I set the datetime variables to Date.MinValue.Then when I populate my textboxes I check if the value of the date variables are Date.Minvalue and I set the textbox text to an empty string.
Code: If(File.OpenedDate = Date.MinValue, String.Empty, File.OpenedDate.ToString("yyyy/MM/dd")) However whe I try to save the data to my sql server db I get a datetime out of range error. What is the correct way to handle these null values in my date columns?
I am converting my datatable to LISt using LINQ how do I handle nulls coming from database
List<Port> portDetails = new List<Port>(); DataTable dt = ds.Tables[0]; portDetails = (from q in dt.AsEnumerable() select new Port { PortCode = q.Field<string>("Code"), ExtCode = q.Field<string>("Nb"), Name = q.Field<string>("Name")) }).ToList();
In the above query if Code is null I do not want property portcode to be set to the value it should only set if it is not null or not blank PortCode = q.Field<string>("Code"),
What should be syntax I was trying somethign like this which doesnt work Portcode = q.Field<bool>("Code") == null ? null : q.Field<bool>("Code")
i am trying to write a stored procedure which constructs an email containing a table. typically, when creating a string of HMTL code, i might have something like:
@strEmail = @strEmail + chkNum + '<br>'
but how do you handle it if the html needs single quotes?
Both the Method 1 and Method 2 can handle the paging of GridView, could you tell me how about the performance of the Method 1?and how much will Method 1 slower than Method 2
#region ForPaging public static List<HD_ToDoList> Get_ToDoListByUserNameForPage(string username, int StartIndex, int PageSize) {
I am using the DetailsView Control to read a LastUpdatedDate field (which can be null until an update is performed) from the database. The LastUpdatedDate is of type DateTime saved in UTC. With the DetailsView control, I can use the NullDisplayText property of the boundfield to safely display an custom message. However, once converted to a template field, that property is lost. Now, how would I display that message if the field is null as I am also formatting the date for display to show in local time.
I'm creating a site that will offer several different services (blogs, videos, images..), all under the same site.
Each service will use a separate database and all services must use the same membeship info. Users will only need one login to access all these services.
For the membership database i will use the default aspnetdb database.
There are two ways i can think of:
1) Use a join-query between two databases, each time i want to show some service records per user.
2) Create a custom membership-info table in each service's database, and keep it in sync with the master membership table in aspnetdb database.
