Question

我收到此错误 -- TypeError：无法读取未定义的属性“行”，这是怎么回事？这可能是我遗漏的很小的东西。 getMerchants 和 resolve(result.rows) 出现错误

const Pool = require('pg').Pool
const pool = new Pool({
    user: 'my_user',
    host: 'localhost',
    database: 'my_database',
    password: 'root',
    port: 5432,
});

const getMerchants = () => {
    return new Promise(function(resolve, reject) {
        pool.query('SELECT * FROM userIds ORDER BY id ASC', (error, results) => {
            if (error) {
                reject(error)
            }
            resolve(results.rows);
        })
    })
}
const createMerchant = (body) => {
    return new Promise(function(resolve, reject) {
        const { name, email } = body
        pool.query('INSERT INTO userIds (name, email) VALUES ($1, $2) RETURNING *', [name, email], (error, results) => {
            if (error) {
                reject(error)
            }
            resolve(`A new merchant has been added added: ${results.rows[0]}`)
        })
    })
}
const deleteMerchant = () => {
    return new Promise(function(resolve, reject) {
        const id = parseInt(Request.params.id)
        pool.query('DELETE FROM userIds WHERE id = $1', [id], (error, results) => {
            if (error) {
                reject(error)
            }
            resolve(`Merchant deleted with ID: ${id}`)
        })
    })
}

module.exports = {
    getMerchants,
    createMerchant,
    deleteMerchant,
}

Answer 1

根据我的评论：

<块引用>

查询的第二个参数是查询参数，不是回调函数。如果没有参数，则传入 []。除此之外，您的代码看起来在很大程度上是多余的。您应该遵循库提供的正确异步模式，而不是重新创建所有那些无用的承诺...

const getMerchants = () => pool.query('SELECT * FROM userIds ORDER BY id ASC');

然后像这样使用它：

const {rows} = await getMerchants();

类型错误：无法读取未定义的属性“行”

1 个答案: