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;
using System.Collections.Generic;

namespace npq {
	
	
	/// <summary>
	/// Encapsulates the access to the result
	/// </summary>
	public class Result : IDisposable {
		PostgreSQL psql;
		IntPtr res;
		ExecStatusType status;
		bool valid;
		int columns, rows;
		string[] columnNames;
		
		/// <summary>
		/// Constructor
		/// </summary>
		public Result(PostgreSQL _psql, IntPtr _res) {
			psql = _psql;
			res = _res;
			if (res == IntPtr.Zero)
				throw new PostgreSQLException("Result is IntPtr.Zero");
			
			status = PG.PQresultStatus(_res);
			valid =  (status == ExecStatusType.PGRES_COMMAND_OK || status == ExecStatusType.PGRES_TUPLES_OK);	
			columns = PG.PQnfields(res);
			rows = PG.PQntuples(res);
			columnNames = new string[columns];
			for(int i=0; i<columns; i++)
				columnNames[i] = PG.PQfname(res, i);
			
			if (status != ExecStatusType.PGRES_COMMAND_OK && status != ExecStatusType.PGRES_TUPLES_OK) {
				string message = PG.PQresultErrorMessage(res);
				Dispose();
				throw new PostgreSQLException(message);
			}
		}
		
		/// <summary>
		/// Free ressources
		/// </summary>
		public void Dispose() {
			if (res != IntPtr.Zero) {
				PG.PQclear(res);
				res = IntPtr.Zero;
			}
		}

		/// <value>
		/// The number of rows affected
		/// </value>
		public int AffectedRows { get { return PG.PQcmdTuples(res); } }
		
		/// <value>
		/// Returns true, if the result is empty
		/// </value>
		public bool Empty { get { return rows == 0; }}
		
		/// <value>
		/// Returns true, if the result is valid
		/// </value>
		public bool Valid { get { return valid; }}
		/// <value>
		/// Returns the Status
		/// </value>
		public ExecStatusType Status { get { return status; }}
		
		/// <value>
		/// Returns the number of columns in the result
		/// </value>
		public int Columns { get { return columns; }}
		/// <value>
		/// Returns the number of rows in the result
		/// </value>
		public int Rows { get { return rows; }}
		
		/// <value>
		/// Access to the data
		/// </value>
		public string this[int row, int column] {
			get { 
				if (row < 0 || row >= rows || column < 0 || column >= columns)
					throw new PostgreSQLException("Row or column index out of range!");
				return PG.PQgetvalue(res, row, column);
			}
		}
	
		/// <value>
		/// Access to the data
		/// </value>
		public string this[int row, string column] {
			get { 
				if (row < 0 || row >= rows)
					throw new PostgreSQLException("Row index out of range!");
				for(int i=0; i<columns; i++) {
					if (columnNames[i] == column)
						return PG.PQgetvalue(res, row, i);
				}
				throw new PostgreSQLException(string.Format("Column {0} not found!", column));
			}
		}
		
		public int ColumnIndex(string column) {
			for(int i=0; i<columns; i++) {
				if (columnNames[i] == column)
					return i;
			}
			throw new PostgreSQLException(string.Format("Column {0} not found!", column));
		}
		
		/// <summary>
		/// Returns the column name
		/// </summary>
		public string ColumnName(int column) {
			if (column < 0 || column >= columns)
				throw new PostgreSQLException("Column index out of range!");
			return columnNames[column];
		}

		/// <summary>
		/// Returns the column name
		/// </summary>
		public string ColumnTypeName(int column) {
			if (column < 0 || column >= columns)
				throw new PostgreSQLException("Column index out of range!");
			return PG.PQftypename(psql.conn, PG.PQftype(res, column));
		}

		/// <summary>
		/// Returns the column type
		/// </summary>
		public int ColumnType(int column) {
			if (column < 0 || column >= columns)
				throw new PostgreSQLException("Column index out of range!");
			return PG.PQftype(res, column);
		}

		public bool GetBoolean(int row, int column) { return bool.Parse(this[row, column]); }
		public byte GetByte(int row, int column) { return byte.Parse(this[row, column]); }
		public short GetShort(int row, int column) { return short.Parse(this[row, column]); }
		public int GetInt(int row, int column) { return int.Parse(this[row, column]); }
		public long GetLong(int row, int column) { return long.Parse(this[row, column]); }
		public float GetFloat(int row, int column) { return float.Parse(this[row, column]); }
		public double GetDouble(int row, int column) { return double.Parse(this[row, column]); }

		public void Dump() {
			for(int col=0; col<columns; col++)
				Console.Write("{0, 15}", columnNames[col]);
			Console.WriteLine();
			for(int row=0; row<rows; row++) {
				for(int col=0; col<columns; col++)
					Console.Write("{0,15}", this[row, col]);
				Console.WriteLine();
			}
		}
	}
}