public static int delete(String sql, List<Param> params)throws SQLException{
		C3p0Pool pool = C3p0Pool.getInstance();
		Connection conn = pool.getConnection();
		PreparedStatement statement = conn.prepareStatement(sql);
		if(params!=null){
			int i=1;
			for(Param p:params){
				if(p.getColumnType()==ColumnType.Date){
					statement.setDate(i++, (Date)p.getValue());		
				}else if(p.getColumnType()==ColumnType.DateTime){
					statement.setDate(i++, (Date)p.getValue());		
				}else if(p.getColumnType()==ColumnType.Integer){
					statement.setInt(i++, (Integer)p.getValue());		
				}else if(p.getColumnType()==ColumnType.BigInt){
					statement.setLong(i++, (Long)p.getValue());		
				}else if(p.getColumnType()==ColumnType.String){
					statement.setString(i++, (String)p.getValue());		
				}else if(p.getColumnType()==ColumnType.DateTime){
					statement.setTimestamp(i++, (Timestamp)p.getValue());		
				}else if(p.getColumnType()==ColumnType.String){
					statement.setString(i++, (String)p.getValue());		
				}
			}			
		}

		try{
			log.info(sql);
			return statement.executeUpdate();
		}finally{
			statement.close();
			conn.close();
		}
	}