How can I convert Dataset column value to an integer

Question

public DataSet ds = new DataSet();
public SqlDataAdapter adapter = new SqlDataAdapter();

public int AuthenticatedUserAge(String User_name)
{
    string sql = "SELECT UserName, Age FROM tblDataProg WHERE (UserName ='" +   User_name  + "')";
    ds = GetDataSet(sql);
    int help = int.Parse(ds.Tables[0].Rows[0]["Age"].ToString());
    return help;    
}

public DataSet GetDataSet(string sql)
{
    SqlConnection connection = new SqlConnection(ConnStr());
    SqlCommand cmd = new SqlCommand();
    cmd.CommandText = sql;
    cmd.Connection = connection;
    adapter = new SqlDataAdapter(cmd);
    connection.Open();
    adapter.Fill(ds);
    connection.Close();
    return ds;
}    

public string ConnStr()
{
    return @"Data Source=.\SQLEXPRESS;AttachDbFilename='G:\עבודת גמר תכנות\v5\חדש תיקיה 1\v4\App_Data\SiteDB.mdf';Integrated Security=True;User Instance=True";
}

I need to check that the value that is returned from AuthenticatedUserAge is a number less than 17 that it will write hello teenager else write hello adult.

The problem I think is this line doesn't return a value:
int help = int.Parse(ds.Tables[0].Rows[0]["Age"].ToString());
it throws this error:

Input string was not in a correct format

Can you please show us how you are actually calling these methods in your code? For example, where do you assign to the `username` session variable? — shree.pat18, May 18 '14 at 15:22
What is returned? If it throws an error, what error is thrown? Have you set breakpoints and debugged this? — Phil Sandler, May 18 '14 at 15:29
it throws this error: Input string was not in a correct format. — user3649869, May 18 '14 at 16:16
it throws this error: Input string was not in a correct format @Phil Sandler — user3649869, May 18 '14 at 16:23
Is the column in the SQL Table an Integer? From what I am reading, you are having trouble with the Age Column? It could be a simple matter of an ALTER Statement in SQL to correct the data type.. Then, you don''t have to do all of these code gyrations. — Leptonator, May 18 '14 at 16:30
i checkd 10 times the type age in the table is int @Leptonator — user3649869, May 18 '14 at 16:33

score 0 · Answer 1 · answered May 18 '14 at 17:51

This is not really an answer, but it will not be clear in a comment.

Break this line up:

int help = int.Parse(ds.Tables[0].Rows[0]["Age"].ToString());

Into:

//set a breakpoint on the next line
string temp = ds.Tables[0].Rows[0]["Age"].ToString(); 
//take one step (F10) over the break and hover over temp
//or use a watch.  What is the value of temp?
int help = int.Parse(temp);

score 0 · Answer 2 · edited May 23 '17 at 10:29

The value in the database for that user's age must be NULL.
You need to check for NULL, and to be safe you should also check for no results returned from the database.

public int AuthenticatedUserAge(String User_name)
{
    string sql = "SELECT UserName, Age FROM tblDataProg WHERE (UserName ='" +   User_name  + "')";
    ds = GetDataSet(sql);
    //check for no results
    if(ds.Tables.Count == 0 || ds.Tables[0].Rows.Count == 0)
    {
       return 0;
    }
    //check for null
    if(ds.Tables[0].Rows[0]["Age"] == DBNull.Value)
    {
       return 0;
    }
    int help = int.Parse(ds.Tables[0].Rows[0]["Age"].ToString());
    return help;    
}

furthermore you REALLY should not be using dynamic SQL - please use parameters instead. Read this.

score 0 · Answer 3 · edited Mar 16 '16 at 23:26

Use the TryParse method to prevent an error:

public int AuthenticatedUserAge(String User_name)
{
    string sql = "SELECT UserName, Age FROM tblDataProg WHERE (UserName ='" +   User_name  + "')";
    ds = GetDataSet(sql);
    int help = 0;
    int.TryParse(ds.Tables[0].Rows[0]["Age"].ToString(), out help);
    return help;    
}

With the above code, if an error occurs, the value of help will remain at its initialization value (in this case, 0).

score 0 · Answer 4 · edited Feb 27 '17 at 10:21

0

Try this. It will help you.

int help = Convert.ToInt32(ds.Tables[0].Rows[0]["Age"]);

edited Feb 27 '17 at 10:21

Ankita Shah

1,818
11
30

answered Feb 27 '17 at 10:08

Ajsatis

31
2

score 0 · Answer 5 · answered May 09 '18 at 19:26

0

Probably age field is Null you may use this to identify and set a default value.

int Help = ds.Tables[0].Rows[0]["Age"] != DBNull.Value ? Convert.ToInt16(ds.Tables[0].Rows[0]["Age"]) : 0;

answered May 09 '18 at 19:26

Ozkan Konca

61
4

How can I convert Dataset column value to an integer

5 Answers5