如何在MySQL中建立会计系统的表结构以满足不同的会计需求？

CREATE TABLE accounts (
    account_id INT AUTO_INCREMENT PRIMARY KEY,
    account_name VARCHAR(50) NOT NULL,
    account_type VARCHAR(20) NOT NULL
);

CREATE TABLE cost_centers (
    cost_center_id INT AUTO_INCREMENT PRIMARY KEY,
    cost_center_name VARCHAR(50) NOT NULL,
    cost_center_type VARCHAR(20) NOT NULL
);

CREATE TABLE vouchers (
    voucher_id INT AUTO_INCREMENT PRIMARY KEY,
    voucher_date DATE NOT NULL,
    voucher_type VARCHAR(20) NOT NULL,
    voucher_number INT NOT NULL,
    description VARCHAR(100)
);

CREATE TABLE voucher_lines (
    line_id INT AUTO_INCREMENT PRIMARY KEY,
    voucher_id INT NOT NULL,
    account_id INT NOT NULL,
    cost_center_id INT,
    debit DECIMAL(10, 2),
    credit DECIMAL(10, 2),
    FOREIGN KEY (voucher_id) REFERENCES vouchers(voucher_id),
    FOREIGN KEY (account_id) REFERENCES accounts(account_id),
    FOREIGN KEY (cost_center_id) REFERENCES cost_centers(cost_center_id)
);

CREATE TABLE balances (
    balance_id INT AUTO_INCREMENT PRIMARY KEY,
    account_id INT NOT NULL,
    period_start DATE NOT NULL,
    period_end DATE NOT NULL,
    initial_balance DECIMAL(10, 2),
    final_balance DECIMAL(10, 2),
    FOREIGN KEY (account_id) REFERENCES accounts(account_id)
);