REST API examples and queries

Querying your database is an essential part of any application. restdb.io uses plain URLs with simple parameters and JSON documents to query your database. In this section we will give you plenty of REST API examples using MongoDB like query syntax.

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Query language

Database queries are created as valid JSON documents. A query object consists of fields and operators that make up a complete query. Please note that query fields are case sensitive.

A simple query example:

https://mydb-fafc.restdb.io/rest/customers?q={"status": "GOLD"}

Which is the same as asking the database: fetch all records with status GOLD

Please note that maximum 1000 records are returns from any query unless the $max parameter is specified.

Simple queries

Match a single field (find Joe):

https://mydb-fafc.restdb.io/rest/people?q={"name": "Joe"}

Match multiple fields (find Joe who's 17):

https://mydb-fafc.restdb.io/rest/people?q={"name": "Joe", "age": 17}

In addition to query simple fields, you can use special operators to perform more advanced queries.

Logic operators

$not operator

Return documents not matching the query.

https://mydb-fafc.restdb.io/rest/people?q={"name" : {"$not" : "Joe"}}

$in operator

Return documents matching any values.

https://mydb-fafc.restdb.io/rest/people?q={"name" : {"$in" : ["Joe", "Jane", "Donald"]}}

$nin operator

Return documents not matching any of the values.

https://mydb-fafc.restdb.io/rest/people?q={"name" : {"$nin" : ["Joe", "Jane", "Donald"]}}

$regex operator

Match a regular expression against field.

https://mydb-fafc.restdb.io/rest/people?q={"name" : {"$regex" : ".Joe*"}}

$or operator

Return documents that matches one or the other field.

https://mydb-fafc.restdb.io/rest/people?q={"$or": [{"name": "Jane"}, {"name": "Donald"}]}

$and operator

Return documents both fields.

https://mydb-fafc.restdb.io/rest/people?q={"$and": [{"name": "Jane"}, {"last-name": "Cassidy"}]}

Logical operators overview

Conditional operators

$gt operator

Return documents that matches each field value greater than numeric value.

https://mydb-fafc.restdb.io/rest/people?q={"salary": {"$gt": 10000}}

$gte operator

Return documents that matches each field value greater than or equal to numeric value.

https://mydb-fafc.restdb.io/rest/people?q={"salary": {"$gte": 10000}}

$lt operator

Return documents that matches each field value less than numeric value.

https://mydb-fafc.restdb.io/rest/people?q={"salary": {"$lt": 10000}}

$lte operator

Return documents that matches each field value less than or equal to numeric value.

https://mydb-fafc.restdb.io/rest/people?q={"salary": {"$lte": 10000}}

$bt operator

Return documents that matches each field value between two numeric values.

https://mydb-fafc.restdb.io/rest/people?q={"salary": {"$bt": [5000, 7500]}}

$exists operator

Return documents that matches each field with a value.

https://mydb-fafc.restdb.io/rest/people?q={"field": {"$exists": true}}

$exists (sub array) operator

Return documents that matches each sub field with any value.

https://mydb-fafc.restdb.io/rest/people?q={"field.0": {"$exists": true}}

$elemMatch operator

Return documents that matches at least one of the elements in an array field.

https://mydb-fafc.restdb.io/rest/people?q={"contact":{"$elemMatch":{"name":"Anderson", age:35}}}

$distinct operator

Return array of unique values from matching fields.

https://mydb-fafc.restdb.io/rest/people?q={"$distinct": "age"}&sort=age

Example output:
[
 "18",
 "19",
 "20",
 "21",
 "22",
 "23",
 "24",
 "25",
 "26"
 ]

Conditional operators overview

Date operator

Querying based on dates are done using the $date operator combined with ISO date strings. For example:

// between two dates
{"_changed":{"$gt":{"$date":"2016-08-01"},"$lt":{"$date":"2016-08-05"}}}

Dynamic date variables

To enable more dynamic queries using the $date operator, like "get all records this month", we have added a number of predefined date variables.

// older than the time just now
{"startat":{"$lt":{"$date":"$now"}}}

We also support MomentJS. Check out their docs and compose the date variable like this:

{"startat":{"$gt":{"$date":"$moment.endOf.hour"}}}
{"startat":{"$gt":{"$date":"$moment.subtract.3.days"}}}
{"startat":{"$gt":{"$date":"$moment.subtract.3.hours"},"$lt":{"$date":"$moment.add.3.hours"}}}
{"startat":{"$gt":{"$date":"$moment.startOf.year"},"$lt":{"$date":"$moment.endOf.year"}}}

Sort operator

The $orderbyoperator lets you sort the result from a query. You can sort on single or multiple fields within the same query. We use the URL parameter hint h={..} to specify sorting.

E.g. query all records from peopleand sort the result set by name in ascending order, and then by age in descending order.

https://mydb-fafc.restdb.io/rest/people?q={}&h={"$orderby": {"name": 1, "age": -1}}

URL Parameters overview

As part of the REST API, restdb.io has a number of parameters that we can use. They are added to the REST URLs as query parameters shown below:

https://<db-name>.restdb.io/rest/<collection>[.<format>]?q={}&h={}&...

The following table shows all valid URL parameters to a database REST endpoint:

Query examples

The following table shows some examples on how to query restdb.io:

Comprehensive code examples for various languages

SQL to NoSQL mapping

The following table shows how traditional SQL statements are expressed as RestDB Queries.