如何从 Deno 的 sqlite 库中获取对象数组？

Question

我正在尝试从 sqlite 获取 user.foo 和 user.bar 而不是一组值：

https://deno.land/x/sqlite

    let user: any = await db.query('SELECT id, email, hashed_password FROM users WHERE email = ?', [body.email]);

    if (!user || !user.length) {
      context.response.status = 400;
      context.response.body = { message: "User not found" };
      return;
    }   
    user = user[0];
    console.log(user);
    console.log(body.password, user[2]);
    const comparison = await bcrypt.compare(body.password, user[2]);
    console.log('comparison: ', comparison);

这可能吗？

编辑：我在这里仍然收到一个错误，即查询没有返回任何行，即使它在 try catch 中（并且行确实存在）

    try {
      const query = db.prepareQuery<[number, string]>("SELECT id, email, hashed_password FROM users WHERE email = ?",
      [body.email],
     );
      user = query.oneEntry();
    } catch(err) {
      console.error(err);
      context.response.status = 400;
      context.response.body = { message: "User not found" };
      return;
    }

    console.log('user: ', user);

Answer 1

    let user: any;

    try {
      const query = db.prepareQuery<string>("SELECT id, email, hashed_password FROM users WHERE email = :email",
     );
      user = query.oneEntry({ email: body.email });
      query.finalize();
    } catch(err) {
      console.error(err);
      context.response.status = 400;
      context.response.body = { message: "User not found" };
      return;
    }

    console.log('user: ', user);

Answer 2

假设您指的是https://deno.land/x/sqlite 的模块，您可以使用以下方法从您的查询中接收对象行：

• db.queryEntries
• PreparedQuery 上的*Entries 方法之一（例如pq.allEntries、pq.iterEntries、pq.oneEntry）

您可以在查询语句和参数中使用positional or named parameters。在https://www.sqlite.org/lang_expr.html#parameters 阅读更多内容。

这是一个完整的工作示例，改编自您的问题代码：

so-69784761.ts

import {DB, PreparedQuery, Row, RowObject} from 'https://deno.land/x/sqlite@v3.1.1/mod.ts';

const db = new DB();
const preparedQueries: PreparedQuery[] = [];

function initialize (): void {
  db.query(`
  CREATE TABLE IF NOT EXISTS users (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    email TEXT NOT NULL UNIQUE,
    hashed_password TEXT NOT NULL
  );
  `);
}

function cleanup (): void {
  // All prepared queries need to be finalized before closing the db
  for (const pq of preparedQueries) pq.finalize();
  db.close();
}

type DBUser = {
  id: number;
  email: string;
  hashed_password: string;
};

function main () {
  initialize();

  // The first two generics don't matter: we don't receive or use the return value
  const insertUserQuery = db.prepareQuery<Row, RowObject, Omit<DBUser, 'id'>>(`
  INSERT INTO users (email, hashed_password)
  VALUES (:email, :hashed_password);
  `);
  preparedQueries.push(insertUserQuery);

  for (const user of [
    {email: 'a@example.com', hashed_password: 'a123'},
    {email: 'b@example.com', hashed_password: 'b123'},
  ]) insertUserQuery.execute(user);

  const findUserByEmailQuery = db.prepareQuery<
    [DBUser['id'], DBUser['email'], DBUser['hashed_password']],
    DBUser,
    [DBUser['email']]
  >(`
  SELECT id, email, hashed_password
  FROM users
  WHERE email = ?;
  `);
  preparedQueries.push(findUserByEmailQuery);

  function findUserByEmail (email: DBUser['email']): DBUser | undefined {
    try {
      return findUserByEmailQuery.oneEntry([email]);
    }
    catch {
      return undefined;
    }
  }

  let user = findUserByEmail('a@example.com');
  console.log(user?.email, user?.id, user?.hashed_password);

  user = findUserByEmail('b@example.com');
  console.log(user?.email, user?.id, user?.hashed_password);

  cleanup();
}

main();

deno run so-69784761.ts
a@example.com 1 a123
b@example.com 2 b123