I have a datareader like so but when it encounters a NULL database value, I get the error message "Conversion from type 'DBNull' to type 'String' is not valid."
Dim myReader As SqlDataReader = myCommand.ExecuteReader()
Dim yValues As New List(Of Double)
With myReader
If .HasRows Then
While .Read
yValues.Add(Double.Parse(.GetValue(0)))........
I'm developing a website using asp.net 2.0 . I have retrieved a record from database through the query.
SqlConnection con = new SqlConnection(connectionstring);
con.Open();
String SQL = "SELECT * FROM Table where attribute1 = value";
SqlCommand cmd = new SqlCommand(SQL, con);
SqlDataReader reader = cmd.ExecuteReader();
Sometimes, there is no record matching this query and so null value is retrieved. My question is how to find that the null value is returned. Since If (no record found i.e NULL) certain actions needs to be done and if (records found i.e NOT NULL) ceratin different actions needs to be carried out.
here is my code which is working fine to read batabase image from database but if there is NULL value in database so how can i read physical path noimage.jpg
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Is there a cleaner way to check for a null value comming from the database?
Right now i am doing this
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There has to be a better what than doing this on every row which could possibly be null
I am having trouble parsing the following xml file because it has so many xmlns.
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I need to get the Name = AdminAcct and role = Administrator. However, for some users the <role></role> tag may not be present.
I have not been able to create a function to take a long nvarchar (8000) with a delimeter to return the results in a table . I have a script version that works as a query. I plan to use the Function in a Select * FROM table WHERE FirstName IN dbo.ListOfItem(@InputList) Is the following posible in SQL Server 2005?What is wrong with syntax? Is there a better solution?
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I have setup my business object to have a create_date and edit_date members both datetime datatypes. My company want to display the create_date and edit_date fields in a gridview for each transaction. The problem i have is that after insterting a record it will have a valid create_date but no edit_date and when displayed in the gridview it defaults to datetime.minvalue (My default). How on earth do i show an empty field in my gridview for a null datetime field in the database?
I am using similar architecture to the Imar Spaanjaars example of a tiered solution. With a few small tweeks it has worked well for me for ages. I am passing a List<Database> to my object datasource which connects to my gridview.
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#?
View 1 RepliesI have a text area that allow user the type in an address in free format, how do I parse the address user entered into address1, address2, city, state, zip and country and save into DB?
View 4 RepliesHow i can make the normal search string to sql server full text search parse, because when we are user enyer search text "how to run windows schedule in C#", in database we have article to to this, but data not returning and sometime is say error in key word and etc.
View 1 RepliesIf Request.QueryString("departmentId").ToString() = "0" Then
SqlDataSource1.SelectParameters.Add("departmentId", TypeCode.Int32, 0.ToString())
I want to add a null value instead of 0.string() for the sqlparameter departmentId how do I do this?
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.
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here is my update query syntax.my problem is.if i update only logo1 and logo3 with null logo2 and img null then my query should be update the other record.just dont update null value record but other should be update.but below my query can not update any record.
UPDATE tbitem set itemname= @itemname,note=@note,
price=@price,qty=@qty,logo1=@logo1,
logo2=@logo2,logo3=@logo3,img=@img
where id =@id
and @logo1 is
null and @logo2
is null
and @logo3
is null
and @img is
null
having a table with column having null values
how to identify row of a column contains null value?
i tried isnull,nullif properties but such functions im getting emptied rows
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.
View 3 RepliesHow can i get the values even when the Source or url is null from the below query
SELECT a.id,
isnull((SELECT STUFF((SELECT
'<li><a href="'+url+'">'+Source_Name+'</a>
<span>(' + k.Source +')</span></li>' end
FROM table1 i, table2 k, table3 j where
i.CategoryID = j.Category_ID and i.CategoryID = c.Category_ID and i.Source = k.ID
FOR XML PATH('')),1, 0, '')), '') AS Source_url,
FROM @table4 c INNER JOIN table5 v
on c.Category_ID = v.Category_ID
I have a dropdown list that uses an ObjectDataSource. The select method of the ObjectDataSource needs to localize the TextField, so i create a Dictionary<int, string> and use GetLocalResourceObject as such:
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In the Local Resource file, there is status0, status1, and status2, all with a value (Deleted, Active, Inactive). The dropdown and object datasource like:
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Now, if I use an ObjectDataSource and put the DropDownList's DataSourceID to it, I will get a null reference on the lookup to the GetLocalResourceObject. BUT If I manually set DataSource/DataBind on the dropdown list on Page_Load, it works fine:
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OR If I move the status values to a global resource file and use GetGlobalResource instead of GetLocal, it works fine! Why can I not use an ObjectDataSource and LocalResourceObject in this way?
i have some problem in passing null value to an integer datatype in sql. Here is my code:-
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The if statement within query is where i am having problem!
Assume in my table named school has a column named StudentNo
I try this script
select * from school where StudentNo <> 'AA'
I just wondering why this where clause "where StudentNo <> 'AA' always return false when StudentNo is null?
In following SQL query: SELECT DISTINCT CodeID, CodeDesc FROM Faults.TblFltClearCodes AS TblFltClearCodes
I am getting a list but there is no null value.Within this query I would like to get only one NULL value at the top and then the list.How to do this? Explicitly I am not allowed to give a null value in the table in DB.
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iam using asp.net2.0 with c# with sql server 2000 when iam executing the procedure in local system it is working fine.but when iam executing in client system procedure returns null value, i have checked all connection string , and session value all are working
My SQL field 'modified' is a DateTime type and if the value is NULL in SQL I want to display a 'n/a' string.
I am using FormView templates to display the value.If I use this statement -> ISNULL(Items.modified,'') AS Modified; I get '1/1/1900 12:00:00 AM' in return.If I use this statement -> ISNULL(Items.modified,'n/a') AS Modified; I get 'Conversion failed when converting datetime from character string.'I could go ahead and change my class from "public DateTime Modified" to "public String Modified" but I want the field to represent its real value which is DateTime.I am not inserting the date value back into the table since the sprocs all take care of that for me. I just want to display the 'n/a' string.So, is there any way to display a SQL DateTime type as a string when its value is NULL inside the table?
what i would like to do is when the value of my sqldatasource is returned, then if it is null, run a code, in my case, redirect them to the login page, heres my code:
string connectionString = ConfigurationManager.ConnectionStrings["PokemonPlanetConnectionStrings"].ConnectionString;
string insertSql = "SELECT * FROM LoggedInUsers WHERE UserId = @UserId";
using (SqlConnection myConnection = new SqlConnection(connectionString))
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Now what i would simply like to do is, if the select statement searches the database, and the result is not found, the simply redirect them to "register.aspx"
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?
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