specified cast is invalid

[arial]

Hi

I am new to programming. learning c# , asp.net.

write a simple program: to get the id from database and save it to arraylist to find the max(id).

and getting exception: Specified cast is invalid.

at line: int low = (int)arrm[i];

Appreciate any help.

Thanks

[r035198x]

Thanks Plater for all your help.

By after making a changes you suggested Now I am getting new error:

Index was outside the bounds of the array.

at line: int temp=reader.Get Int32(1);

Can you post what you have now(using code=css tags ofcourse)?

[arial]

I am not sure how to do CSS. so, here is what I have.

cmd4.CommandText = "select id from dpt" ; 

cmd4.ExecuteNonQuery();

SqlDataReader reader = cmd4.ExecuteReader();

while(reader.Read())

{

int temp=reader.GetInt32(1);

arrm.Add(temp);}

reader.Close();

cmcmd4.Connection.Close();

int max = 0;

for (int i = 0;i<arrm.Count;i++)

{

int min = (int) arram[i];

if (max < min)

max = min;

}

[r035198x]

I am not sure how to do CSS. so, here is what I have.

cmd4.CommandText = "select id from dpt" ; 

cmd4.ExecuteNonQuery();

SqlDataReader reader = cmd4.ExecuteReader();

while(reader.Read())

{

int temp=reader.GetInt32(1);

arrm.Add(temp);}

reader.Close();

cmcmd4.Connection.Close();

int max = 0;

for (int i = 0;i<arrm.Count;i++)

{

int min = (int) arram[i];

if (max < min)

max = min;

}

No that's not what I meant. I meant that you wrap all the code in one set of code tags not broken up like that and then when you have all the code wrapped in one set of code tags, you add =css to the opening code tag so that your opening code tag looks like this
[code=css].

[arial]

Ok. I got it, here it is:

 cmd4.CommandText = "select id from dpt" ; 
cmd4.ExecuteNonQuery();
SqlDataReader reader = cmd4.ExecuteReader();
while(reader.Read())
{
int temp=reader.GetInt32(1);
arrm.Add(temp);
}
arrm.Sort();
reader.Close();
cmd4.Connection.Close();
 
int max = 0;
for (int i = 0; i < arrm.Count; i++)
{
int min = (int)arrm[i];
if (max < min)
max = min;
}

Thanks,

[Plater]

Try making it:
int temp=reader.Get Int32(0);

I wasn't sure if it was zero one one based index.

[arial]

Hi Plater,

then it is back to original error: specified cast is invalid.

line: int temp=reader.Get Int32(0);

Thanks,

[Plater]

Ok how SURE are you that your ID column is an int?

int temp=-1;
try
{
temp=int.Parse(reader.GetValue(0).ToString());
}
catch(Exception ee)
{//if you make it here, your first column is NOT of datatype int
}
 

[arial]

Hi Plater ,

Thank so very much for all your help.

my first column is id and it is numeric datatype in sql database.

with your help I was able to solve my problem.

But Now, I got one more little issue. which is I am trying to do a query with like clause and i think I am not getting write syntax.

Need help with that please.

Select paperid from Allreport where paperid like ' "+DateTime.Now. ToString("yymm" )+%" ' ;

my paperid will be for this month. 070901,070902 depending on as many time report was modified by user and I like to get the all paperid for a perticular month.

thank you,

[Plater]

That SQL statement looked good, what kind of error are you getting?

[arial]

query is in C# page along with other code.

and I am getting Invalid Expression on % sign.