c# database HELP

raluca mindrut

I am getting this error: "data type mismatch in criteria expression" Can you tell me why?

here's the code

try

{

string constring = @"Provider = Microsoft.ACE.OLEDB.12.0; Data source= bla.accdb;Persist Security Info=True;";

OleDbConnection conexiune = new OleDbConnection(constring);

OleDbCommand cmdDataBase = new OleDbCommand("Select * from Table1 where nume =' " + this.textBox1.Text+"' and parola ='"+this.textBox2.Text+"';", conexiune);

OleDbDataReader myReader;

conexiune.Open();

myReader = cmdDataBase.ExecuteReader();

int count = 0;

while (myReader.Read())

{ count = count + 1; }

if (count == 1)

{

MessageBox.Show("FS");

}

else

{

MessageBox.Show("no");

}

catch (Exception ex)

{ MessageBox.Show(ex.Message); }

}

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes12y ago
If 'nume' is a string in the database, then it looks like you're adding a leading space to what's in textbox1.

If you're getting a count of 0 but are expecting it to be 1, you need to watch out for mis-matches due to leading/trailing spaces or differences in capitalization.
raluca mindrut12y ago
thanks, it works but even if it is correct, it still cout NO
Vulpes12y ago
I would guess that either nume, parola or both are not strings but numeric types within your database.

If that's the case, then don't surround them with single quotes in your Select command.