如何编写nodeJS查询以使用datetime INTERVAL获取postgreSQL数据库的最近24小时记录

Question

I am fetching last 24 hours records from PostgreSQL DB using CURRENT_TIMESTAMP - INTERVAL '24 hours' in my .js file. But I am not able to write it properly due to single inverted commas in query.

I am fetching records from PostgreSQL database and showing them in terms of bar chart using angular 6.

Here is the query I am trying to run from .js file to fetch last 24 hours records:

query = {

    name: 'fetch-chart-data24',

    text: ' SELECT availablecar, recentTime, adrs FROM stations_logs WHERE adrs = $1 AND recentTiontime > CURRENT_TIMESTAMP - INTERVAL '24 hours' ORDER BY recentTime desc',

    values: [req.body.adrs,req.body.param]
}

Final result from query should be most recent 24 hours records for database. Currently I am getting error as

Unexpected number

Answer 1

You can escape single quotes with back slahes ( \\ ) like this:

{
  ...
  text: ' SELECT availablecar, recentTime, adrs FROM stations_logs WHERE adrs = $1 AND recentTiontime > CURRENT_TIMESTAMP - INTERVAL \'24 hours\' ORDER BY recentTime desc',
  ...
}

---

For further reading:

https://www.digitalocean.com/community/tutorials/how-to-work-with-strings-in-javascript#conclusion

Answer 2

query = {
    name: 'fetch-chart-data24',
    text: `SELECT availablecar, recentTime, adrs FROM stations_logs WHERE adrs = $1 AND recentTiontime > CURRENT_TIMESTAMP - INTERVAL '24 hours' ORDER BY recentTime desc`,
    values: [req.body.adrs,req.body.param]
}

You can make use of template literals . Its for embedding expressions, but can satisfy your use case too.