PostgreSQL Synchronization Tool

/* npq - A C# libpq wrapper
 * 
 * The contents of this file are subject to the terms
 * of the Common Development and Distribution License
 * (the "License").  You may not use this file except
 * in compliance with the License.
 *
 * You can obtain a copy of the license at
 * http://www.opensource.org/licenses/cddl1.php.
 * See the License for the specific language governing
 * permissions and limitations under the License.
 *
 * Copyright 2009 by martin.faust@e56.de
 */
using System;

namespace npq {
	/// <summary>
	/// A PostgresSQL connection
	/// </summary>
	public class PostgreSQL : IDisposable {
		internal IntPtr conn = IntPtr.Zero;
		int protocol;
		string version;
		
		/// <value>
		/// Returns the version string of the server
		/// </value>
		public string Version { get { return version; }}
		/// <value>
		/// Returns the protocol version
		/// </value>
		public int Protocol { get { return protocol; }}
		
		/// <summary>
		/// Connect to the database
		/// </summary>
		/// <param name="info">Connection string as described in the libpq docs</param>
		public PostgreSQL(string info) {
			conn = PG.PQconnectdb(info);
			if (PG.PQstatus(conn) != ConnStatusType.CONNECTION_OK)
				throw new PostgreSQLException(PG.PQerrorMessage(conn));
			
			int v = PG.PQserverVersion(conn);
			int major = v / 10000;
			v -= major * 10000;
			int minor = v / 100;
			v -= minor * 100;
			
			version = string.Format("{0}.{1}.{2}", major, minor, v);
			protocol = PG.PQprotocolVersion(conn);
		}

		/// <value>
		/// Returns the last error message
		/// </value>
		public string Error {
			get { return PG.PQerrorMessage(conn); }
		}
		
		/// <summary>
		/// Begin a transaction
		/// </summary>
		public void StartTransaction() { Exec("START TRANSACTION").Dispose(); }

		/// <summary>
		/// Comit transaction
		/// </summary>
		public void ComitTransaction() { Exec("COMMIT").Dispose(); }
		/// <summary>
		/// Rollback a transaction
		/// </summary>
		public void RollbackTransaction() { Exec("ROLLBACK").Dispose(); }
		
		/// <summary>
		/// Excecute a sql query
		/// </summary>
		public Result Exec(string query) { return new Result(this, PG.PQexec(conn, query)); }

		/// <summary>
		/// Free ressources
		/// </summary>
		public void Dispose() {
			if (conn != IntPtr.Zero) {
				PG.PQfinish(conn);
				conn = IntPtr.Zero;
			}		
		}		
	}
}