@Override
	public String toString(){
		
		StringBuilder sb = new StringBuilder();
		sb.append("Table: " + name + "\r\n");
		
		int lines = columns.size()*20;
		StringBuilder fillerSpace = new StringBuilder();
		StringBuilder fillerUnderline = new StringBuilder();
		StringBuilder fillerSpaceL = new StringBuilder();
		StringBuilder fillerUnderlineL = new StringBuilder();
		for(int i=0 ; i<lines ; i++){
			fillerSpace.append(" ");
			fillerUnderline.append("_");
			if(i%20 == 0){
				fillerSpaceL.append("|");
				fillerUnderlineL.append("|");
			}else{
				fillerSpaceL.append(" ");
				fillerUnderlineL.append("_");
			}
		}
		sb.append(fillerUnderline + "\r\n");
		sb.append(fillerSpaceL + "|\r\n|");
		
		for(Entry<String,Column> column : columns.entrySet()){
			Column col = column.getValue();
			sb.append(col.getName() + ":" + col.getType());
			for(int j=0 ; j<20-(col.getName().length() + 2 + col.getType().toString().length()) ; j++)
				sb.append(" ");
			sb.append("|");
		}
		sb.append("\r\n" + fillerUnderlineL + "|\r\n");
		
		return sb.toString();
	}