/// <summary>
/// Creates a prepared version of the command on a PostgreSQL server.
/// </summary>
public override void Prepare()
{
// Check the connection state.
CheckConnectionState();
// reset any responses just before getting new ones
Connector.Mediator.ResetResponses();
// Set command timeout.
m_Connector.Mediator.CommandTimeout = CommandTimeout;
if (!m_Connector.SupportsPrepare)
{
return; // Do nothing.
}
using (m_Connector.BlockNotificationThread())
{
try
{
// Use the extended query parsing...
planName = m_Connector.NextPlanName();
String portalName = m_Connector.NextPortalName();
parse = new NpgsqlParse(planName, GetParseCommandText(), new Int32[] { });
m_Connector.Parse(parse);
// We need that because Flush() doesn't cause backend to send
// ReadyForQuery on error. Without ReadyForQuery, we don't return
// from query extended processing.
// We could have used Connector.Flush() which sends us back a
// ReadyForQuery, but on postgresql server below 8.1 there is an error
// with extended query processing which hinders us from using it.
m_Connector.RequireReadyForQuery = false;
m_Connector.Flush();
// Description...
NpgsqlDescribe describe = new NpgsqlDescribe('S', planName);
m_Connector.Describe(describe);
NpgsqlRowDescription returnRowDesc = m_Connector.Sync();
Int16[] resultFormatCodes;
if (returnRowDesc != null)
{
resultFormatCodes = new Int16[returnRowDesc.NumFields];
for (int i = 0; i < returnRowDesc.NumFields; i++)
{
NpgsqlRowDescription.FieldData returnRowDescData = returnRowDesc[i];
if (returnRowDescData.TypeInfo != null && returnRowDescData.TypeInfo.NpgsqlDbType == NpgsqlDbType.Bytea)
{
// Binary format
resultFormatCodes[i] = (Int16)FormatCode.Binary;
}
else
{
// Text Format
resultFormatCodes[i] = (Int16)FormatCode.Text;
}
}
}
else
{
resultFormatCodes = new Int16[] { 0 };
}
bind = new NpgsqlBind("", planName, new Int16[Parameters.Count], null, resultFormatCodes);
}
catch (IOException e)
{
throw ClearPoolAndCreateException(e);
}
catch
{
// As per documentation:
// "[...] When an error is detected while processing any extended-query message,
// the backend issues ErrorResponse, then reads and discards messages until a
// Sync is reached, then issues ReadyForQuery and returns to normal message processing.[...]"
// So, send a sync command if we get any problems.
m_Connector.Sync();
throw;
}
}
}