问题
I am wiorking on a web application when i click on to fetch data from database i get the following error:
ExecuteReader requires an open and available Connection. The connection's current state is closed.
ExecuteReader requires an open and available Connection. The connection's current state is closed.
I declare my connection on a seperate class as the following:
public Database()
{
valid = false;
using (connection = new SqlConnection(connectionString))
{
connection.Open();
}
}
Where i get the error:
and i call it from a WebForm. Why do i get this error when the connection is already open (I used to use odbc connection and it works fine, however the SqlConnection is not working)
What is the reason?
回答1:
SQL connection is open within using scope only:
using (var connection = new SqlConnection(connectionString)) {
connection.Open(); // open here
...
} // close here
So put your command(s) into the using scope:
using (var connection = new SqlConnection(connectionString)) {
connection.Open();
// command creation and execution should be within connection "using" scope
using (var q = new SqlCommand()) {
q.Connection = connection;
...
// reader should be within command "using" scope
using (var reader = q.ExecuteReader()) {
...
}
}
...
} // close here
来源：https://stackoverflow.com/questions/36179589/executereader-requires-an-open-and-available-connection-the-connections-curre