After some peeking at reflector, the interesting methods here (GetFieldValueAsync<T>, IsDBNullAsync, and the internal method GetBytesAsync) only do “interesting” code for the CommandBehavior.SequentialAccess scenario. So: if you’re not using that: don’t bother – the row data is already buffered in memory, and Task<T> is pure overhead (although it will at least be an already-completed task … Read more
using (var conn = new SqlConnection(SomeConnectionString)) using (var cmd = conn.CreateCommand()) { conn.Open(); cmd.CommandText = “SELECT * FROM learer WHERE id = @id”; cmd.Parameters.AddWithValue(“@id”, index); using (var reader = cmd.ExecuteReader()) { if (reader.Read()) { learerLabel.Text = reader.GetString(reader.GetOrdinal(“somecolumn”)) } } }
You can Install System.Configuration.ConfigurationManager from Nuget Install-Package System.Configuration.ConfigurationManager This problem is a known issue as you can see here and the recommended solution is nuget package https://github.com/pusher/pusher-websocket-dotnet/issues/34
EDIT: The fully managed ODP.NET is now available in production. It is very small (less than 10MB) and is not dependent on other files. You can obtain it here: http://www.oracle.com/technetwork/topics/dotnet/downloads/index.html Original answer: One way to easily ensure that the required Oracle client side software (including ODP.NET) is always available on the deployment machine is to … Read more
Something like this. The example is probably not very good as it doesn’t properly dispose objects but you get the idea. Here’s a cleaned up version: using (var connection = new SqlConnection(ConnectionString)) using (var command = connection.CreateCommand()) { connection.Open(); command.CommandText = “select id from test1; select id from test2”; using (var reader = command.ExecuteReader()) { … Read more
When dealing with varbinary(max), there are two scenarios: the length of the data is moderate the length of the data is big GetBytes() is intended for the second scenario, when you are using CommandBehaviour.SequentialAccess to ensure that you are streaming the data, not buffering it. In particular, in this usage you would usually be writing … Read more
What you are looking for is a SqlException, specifically the violation of primary key constraints. You can get this specific error out of this exception by looking at the number property of the exception thrown. This answer is probably relevant to what you need: How to Identify the primary key duplication from a SQL Server … Read more
You need to specify which column of the datarow you want to pull data from. Try the following: StringBuilder output = new StringBuilder(); foreach (DataRow rows in results.Tables[0].Rows) { foreach (DataColumn col in results.Tables[0].Columns) { output.AppendFormat(“{0} “, rows[col]); } output.AppendLine(); }
Also we can try like this, string[] selectedColumns = new[] { “Column1″,”Column2”}; DataTable dt= new DataView(fromDataTable).ToTable(false, selectedColumns);
You could try something like this: string sql = “SELECT dscr FROM system_settings WHERE setting IN ({0})”; string[] paramArray = settingList.Select((x, i) => “@settings” + i).ToArray(); cmd.CommandText = string.Format(sql, string.Join(“,”, paramArray)); for (int i = 0; i < settingList.Count; ++i) { cmd.Parameters.Add(new SqlParameter(“@settings” + i, settingList[i])); }