Syntax problem in C#

Question

var temp = ConfigurationManager.ConnectionStrings["connectionStr"].ConnectionString; conn = new SqlConnection(temp); conn.Open(); // Create the command SqlCommand command = new SqlCommand("SELECT * FROM View_Patients", conn); command.Connection = conn; RecCount = Convert.ToInt32(command.ExecuteScalar()); last line giving the error "Input String was not in a correct format"

Rafnas T P · Answer

hi, in your select query you are returning morethan one result , if you wanted to get count of rows in a table you can try as follows SqlCommand command = new SqlCommand("SELECT count(*) FROM View_Patients", conn); command.Connection = conn; RecCount = Convert.ToInt32(command.ExecuteScalar(

Nitin Sontakke · Answer

Typically, I avoid using syntax the way you have used it. I would first store the value returned by the ExecuteScalar() to a variable and then pass that variable to the Convert.Int32. This is the best strategy. Furthermore, if you have noticed (and you should always) carefully, ExecuteScalaer returns the Object, which is means it's data type is not clear to ExecuteScalar, which makes sense because it doesn't know what data-type column we will be using in SELECT statement. So change it as follows: Int32 RecCount = Convert.ToInt32(command.ExecuteScalar().ToString()); Another thing is, your intentions are not quite clear here. What exactly are trying to do? You are saying saying 'select *' and not using it's output at all. The value of FIRST column of the FIRST row will be returned to you if you use ExecuteScalar. Then you are storing it in RecCount, which doesn't make any sense at all.