updating a row gives error Operation must use an updateable query - asp.net

Question

I'm getting this error when I'm trying to update a record:
ERROR [HY000] [Microsoft][ODBC Microsoft Access Driver]
Operation must use an updateable query
However when I add a new record, it would add just fine.
I did some searching and found out that the problem is because The ASP.NET worker process does not have permission to update the database. But how am I being able to insert a new record (Isn't inserting updating the database!) but not update (set a record to a different value).
OdbcConnection DbConnection = new OdbcConnection("DSN=inv");
DbConnection.Open();
try
{
string newPassword = password1.Text;
OdbcCommand DbCommand = new OdbcCommand("UPDATE Users" + " SET [Password] = '" + newPassword + "'" + " Where Name = '" + Session["LoginId"] + "'" + ";", DbConnection);
DbCommand.ExecuteNonQuery();
Server.Transfer("Default.aspx", true);
}

Answer 1

You will often get that error if you don't have a primary key declared on that table.
Your code is also pretty ugly, at the very least you should be using a parameterized query:
OdbcCommand DbCommand = new OdbcCommand("UPDATE Users SET [Password] = #Password Where Name = #Name", DbConnection);
var param = DbCommand.Parameters.Add("#Password", OdbcType.Text);
param.Value = passWord;
param = DbCommand.Parameters.Add("#Name", OdbcType.Text);
param.Value = Session["LoginId"];
And I hope this isn't anything more than a toy/demo app -- storing passwords in the clear is bad. Storing passwords in access in the clear is a double bad.