25.2. Database Setup

The Minesweeper game will use a combination of session cookies and database operations to store important information. Let’s begin by getting the database file ready.

25.2.1. Start With an Outline

Before we write any code, we need to think about what data the game needs in order to work. In particular, we want to identify the information to save in the game’s database. There are LOTS of possibilities! However, for our basic game, we want to start small. We can always refine the database structure later!

Consider the data that needs to persist. For example, if a user leaves the game in the middle of play and comes back later, what needs to go into the database to keep a record of their progress?

For starters, our database should save:

  1. Information about each mine hidden on the board. This includes a primary key value as well as a location (row letter plus column number).
  2. Information about each individual cell on the board. This includes a primary key, the cell’s location, the number of mines in surrounding cells, whether the user has clicked the cell, and whether the cell contains a mine.

This outline suggests 2 tables for the database - one for a list of mines, and another for the cells on the game board.

25.2.2. db_setup.py

Use the tools in Visual Studio code to create a new Python file at the same level as main.py. Call the new file db_setup.py. This will be a separate program, and its only job is to create the database file and add two tables.

Follow along with the video to build this program.

Tip

The video player automatically sets the resolution. However, this choice might not be good enough to clearly see all of the text.

If the code looks blurry on your screen, click the gear icon in the video controls and increase the resolution to the maximum value.

Note

For our basic game, we might not use all of the columns in the tables yet. However, they could be useful later, so there’s no harm in adding them now.

25.2.3. Video Summary

Tip

Don’t try to code db_setup.py using only the summary! The clip contains information and specific code instructions that you really shouldn’t skip.

The text by itself doesn’t provide enough detail on its own. It’s a SUMMARY and not a GMESD (Give-Me-Every-Single-Detail).

  1. After creating the game.db database file, add two new tables: mines and board. The first table stores an ID number and location for each mine created in the game. The second table stores information about each cell on the game board.

  2. Adding DROP TABLE commands at the top of the file lets us quickly remove and recreate the two tables. This is useful if we need to make a fresh start.

  3. The mines table includes two columns: mine_id and coordinates. mine_id is the primary key, and its data type must be INTEGER instead of INT. (For some reason, using the INT syntax doesn’t automatically increment the primary key values).

    coordinates is of type TEXT and will store values like C9 or E2.

  4. The board table includes columns for cell_id (the primary key), coordinates, surr_mines (surrounding mines), guessed and mine_id.

    cell_id, surr_mines, and mine_id are integers. coordinates is a text data type, and guessed is a boolean.

  5. No rows need to be added to the mines table at this time. However, the board table does require some information.

  6. A pair of nested loops create a string value for the coordinates of each cell on the board.

  7. The loops also execute a SQL query to insert new rows into the board table. Each new row includes a string for coordinates and the value False for the guessed column.

  8. Note the unused row and column labels (X, Y, 0, and 11). There is a reason for these extra labels, but we won’t explore that until the end of the chapter.