Question

我得到了{{＆＃39; AVG（Price）＆＃39;：＆＃39; 31000.0000＆＃39; }而不是＆＃39; 31000.0000

这是函数

async function getAveragePrice(year) {
const sql = await init();
const [rows] = await sql.query('SELECT AVG(Price) FROM Car where year= 
?', [year], (err, result) => {
  if (err) {
     return null;
  }
 });
 return rows;
}

我正在使用nodejs mysql2

Answer 1

试试这个：

async function getAveragePrice(year) {
  const sql = await init()
  const row = await sql.query('SELECT AVG(Price) AS avg_price FROM Car where year=?', year, (err, result) => {
    if (err) {
      return null
    }
    return result.avg_price
  })
}

Answer 2

1）回调部分是冗余的2）这是预期的行为，.query(sql)返回Promise<array of rows>而行是对象，其中每个键是对应的字段名称

async function getAveragePrice(year) {
  const db = await init();
  const [rows] = await db.query('SELECT AVG(Price) as avg FROM Car where year=?', [year])
  return rows[0].avg;
}

NodeJS mysql查询返回错误的结果

2 个答案: