Check if a record exists in the database

Question

I am using these lines of code to check if the record exists or not.

SqlCommand check_User_Name = new SqlCommand(\"SELECT * FROM Table WHERE ([user] = \'\" +         


        

Answer 1

The ExecuteScalar method should be used when you are really sure your query returns only one value like below:

SELECT ID FROM USERS WHERE USERNAME = 'SOMENAME'

If you want the whole row then the below code should more appropriate.

SqlCommand check_User_Name = new SqlCommand("SELECT * FROM Table WHERE ([user] = @user)" , conn);
check_User_Name.Parameters.AddWithValue("@user", txtBox_UserName.Text);
SqlDataReader reader = check_User_Name.ExecuteReader();
if(reader.HasRows)
{
   //User Exists
}
else
{
   //User NOT Exists
}