dbnull Questions
3
Solved
The stored procedure for command can return null.Is it correct way to check if the returned value is null or should I also check that obj is null?
object obj = command.ExecuteScalar();
int id = -1...
2
Solved
I have the follwoing code that performs a query and returns a result. However, I looked around and found some examples to take care of null values but I get an error: "Invalid attempt to read when ...
Involution asked 31/12, 2013 at 19:57
4
Solved
I frequently have to deal with DataTables connected to grid controls, custom updating always seems to produce a lot of code related to DBNull.Value. I saw a similar question here but think there mu...
3
Solved
I need to parse a value from a DataRow and assign it to another DataRow. If the input is valid, then I need to parse it to a double, or else add a DBNull value to the output. I'm using the followin...
7
If in VB.NET I have DataRow and I want to test whether a column value is Null, should I use:
myDataRow.IsNull("Column1")
OR
IsDBNull(myDataRow("Column1"))
6
Solved
I am using a dataset to pull data from a DB. One of the fields in a row is NULL. I know this. However, the following vb.net code throws a StrongTypingException (in the autogenerated get_SomeField()...
4
Solved
My code is 2x longer than it would be if I could automatically set IsDBNull to "" or simply roll over it without an error.
This is my code:
Dim conn As New SqlConnection
conn.ConnectionString = M...
3
Solved
I have two DateTime objects, BirthDate and HireDate. They are correctly formatted as a string and when I pass them through to my data access layer, they need to be parsed into a DateTime object.
...
3
Solved
I have some textboxes on my page which can be empty because they are optional and I have this DAL code
parameters.Add(new SqlParameter("@FirstName", FirstName));
parameters.Add(new SqlParame...
Zoophobia asked 16/9, 2012 at 2:56
4
I'm getting an error when selecting from a rows.AsEnumerable(). I am using the following code...
var rows = ds.Tables[0].AsEnumerable();
trafficData = rows.Select(row => new tdDataDC
{
Calc...
Squarely asked 29/6, 2010 at 23:13
6
Solved
Is there any difference between null and System.DBNull.Value? If yes, what is it?
I noticed this behavior now -
while (rdr.Read())
{
if (rdr["Id"] != null) //if (rdr["Id"] != System.DBNull.Valu...
2
Solved
Why does the following query raise the error below for a row with a NULL value for barrel when I explicitly filter out those rows in the Where clause?
Dim query = From row As dbDataSet.conformalRo...
9
Solved
I have a table which contains null values and I need to get data from the table using SqlDataReader. I can't figure out how I can safely cast DBNull to int.
I'm doing it in this way at the moment:...
Halsted asked 21/2, 2012 at 12:35
1
Solved
I'm using the SQL Express 2010 query builder. I need to be able to increment a field.
In my behind code, I make a call such as
tableAdapter.IncrementLikeCount(id);
If I just use an increment, t...
Byrnes asked 3/2, 2012 at 22:42
2
Solved
I want to create a stored procedure (in SQL Server 2008 R2) that will update a record in a table based on the table's PK.
The stored proc will have, for example, four parameters:
@ID int,
@Name n...
Brendon asked 12/8, 2011 at 17:2
8
Solved
I'm trying to populate a class object with values from a database table. The someObject.Property field is a nullable int type.
someObject.Property = Convert.ToInt32(dbReader["SomeField"]);
So, i...
1
Solved
I have a Product table with non-null "quantity" (decimal) and "status" (int) columns, and I created a view on this table with the following case expression:
SELECT P.ProductTypeId,
(CASE WHEN P.S...
4
Solved
I understand that the SQL standard allows multiple NULL values in a column that is part of the UNIQUE constraint.
What I don't understand is why the UNION construct (at least in PostgreSQL,) treat...
Supporter asked 20/4, 2011 at 2:50
4
Solved
What are the benefits of using the c# method DataRow.IsNull to determine a null value over checking if the row equals DbNull.value?
if(ds.Tables[0].Rows[0].IsNull("ROWNAME")) {do stuff}
vs
if(d...
2
Solved
I want to return all rows from a SQL Server 2008 database table into a SQL data source if a textBox field is blank. So I made a stored procedure with an if @date IS NULL clause.
Although the stor...
Carpometacarpus asked 21/2, 2011 at 15:51
2
Solved
I use OleDB to read an Excel file. One of the columns has a "Common" format and contains both strings with letters and values consisting of numbers only. String values are retrieved without problem...
2
I'm using a SQL Server 2008 stored procedure to create a new record with
this syntax:
cmd.Parameters.Add("@photo", DBNull.Value)
cmd.ExecuteNonQuery()
but the result is a:
Operand type clash...
Coexist asked 10/3, 2010 at 21:23
3
Solved
I have defined Class Person property Birthday as nullable DateTime? , so why shouldn’t the null coalescing operator work in the following example?
cmd.Parameters.Add(new SqlParameter("@Birthday",...
Thirddegree asked 6/8, 2010 at 15:22
13
Is there a better/cleaner way to do this?
int stockvalue = 0;
if (!Convert.IsDBNull(reader["StockValue"]))
stockvalue = (int)reader["StockValue"];
Lizbeth asked 12/3, 2010 at 13:56
2
Solved
I have the following code
foreach (DataRowView dr in Data)
{
if (dr == System.DBNull.Value)
{
nedID = 1;
}
}
but i get the following error
Operator == cannot be applied to operands of type...
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