CREATE TABLE accounts (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name TEXT NOT NULL,
    type TEXT CHECK(type IN ('asset', 'liability', 'equity', 'revenue', 'expense'))
);

CREATE TABLE journal_entries (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    account_id INTEGER,
    date TEXT,
    description TEXT,
    debit REAL DEFAULT 0,
    credit REAL DEFAULT 0,
    FOREIGN KEY (account_id) REFERENCES accounts(id)
);