行式库与 SQLRow Store & SQL

CREATE TABLE accounts (
  account_id INTEGER PRIMARY KEY,
  account_type TEXT NOT NULL
);
CREATE TABLE transactions (
  tx_id INTEGER PRIMARY KEY,
  account_id INTEGER NOT NULL REFERENCES accounts(account_id),
  tx_date TEXT NOT NULL,
  amount REAL NOT NULL
);
CREATE INDEX idx_tx_account_date ON transactions(account_id, tx_date);
SELECT a.account_type, ROUND(SUM(t.amount), 2) AS net_amount
FROM transactions t JOIN accounts a USING(account_id)
GROUP BY a.account_type ORDER BY net_amount DESC;