Using Socrata SODA API to query most recent rows by datetime

问题

I am new to this site and this is my first question. I am trying to query the "Seattle Real Time Fire 911 Calls" database from the Socrata Seattle Open Data site: https://data.seattle.gov/Public-Safety/Seattle-Real-Time-Fire-911-Calls/kzjm-xkqj. I'm not an expert at using the SODA API, and I'm having difficulty figuring out how to query the most recent entries in the database. All attempts to use the "order" or "where" SoQL statements give me data from 2010 or 2011, and I cannot figure out how to query the most recent 300 entries. Querying the "top" rows yields the oldest entries. Using a full OData feed pull yields data as recent as today, but I need to use a fast json or csv SODA API query.

Note: The datetime field does not respond to any "where" statements that I use.

Thank you!

回答1:

OK, a few tips to get started:

• The $order parameter sorts by default in ascending (ASC) order, so you'll want to actually order by datetime DESC to get the latest records first
• Unfortunately Seattle has a number of crimes that are listed with no datetime, so you'll also want to filter with a $where query to only retrieve results in a date range. $where=datetime > '2014-07-01' works for me, for example
• To only get the top 300 results, you'll want to pass a $limit=300 parameter as well.

Here's a sample request in Runscope for you to try out.

来源：https://stackoverflow.com/questions/25001635/using-socrata-soda-api-to-query-most-recent-rows-by-datetime