what should I do to put some IF for sometimes that my query does not have any answer

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I write this sql query:

C#

SqlCommand cmd2 = new SqlCommand();
       cmd2.Connection = new SqlConnection(Class1.CnnStr);
       cmd2.CommandText = "SELECT MAX(Code) FROM Table WHERE Number=@Number ";
       cmd2.Connection.Open();
       cmd2.Parameters.AddWithValue("@Number", Hidden_txt.Text);
       cmd2.ExecuteNonQuery();

and I want to put some (IF) such as:

C#

if (cmd2.ExecuteScalar()=="Null")
{....}

for sometimes that my query does not have answer but it doesn't work. what should I do to put some IF for sometimes that my query does not have any answer?

Posted 12-Nov-11 1:58am

kitykity

Updated 12-Nov-11 2:05am

Mehdi Gholam

v2

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4 solutions

Solution 1

You can edit your query like this :

SQL

SELECT MAX(ISNULL(Code,0)) FROM Table WHERE Number=@Number

Posted 12-Nov-11 2:08am

Mehdi Gholam

Comments

Amir Mahfoozi 14-Nov-11 7:58am

+5 good solution ;)

Mehdi Gholam 14-Nov-11 8:51am

Cheers

Solution 2

Use a try catch block instead...
Execute your SQL Command and "connection.open" statements in the try clause...

Also since execute non query returns number of rows affected, you can check if the number of rows returned is greater than 0

PS. Use stored Procedures rather than fire the query directly from the code itself

Posted 12-Nov-11 2:09am

qadirv

Solution 4

Hi,
you can try by

C#

int result=-1;
result=cmd2.ExecuteNonQuery();

if(result != -1)
{

}

it will work proper. Because ExecuteNonQuery returns an "int" value indicating the no. of rows affected.so you can try this...

Posted 12-Nov-11 2:46am

Member 8034530

Updated 12-Nov-11 2:58am

v2

Comments

Dalek Dave 12-Nov-11 8:58am

I put a code block in for readability.

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OriginalGriff · Accepted Answer · 2011-11-12T02:10:00

Solution 3

Try:

C#

if (cmd2.ExecuteScalar() == DBNull.Value)
   {
   ...
   }

Posted 12-Nov-11 2:10am

OriginalGriff

Comments

kitykity 12-Nov-11 8:46am

thank you veryyyyy much