Using Variables in your Custom Query

Overview

Neurelo custom queries support variables so that values can be passed in to your queries during run time execution. Here is how to add a variable"

SELECT * FROM "User" where id = {{ id }}

In the above query, {{ id }} is a variable that requires the user to pass the value of "id" at the when calling the endpoint for run-time execution.

When you add a variable to a custom query, remember to specify the data-type for the variable

Accessing custom query API endpoints with variables

Once you have a custom query with variables saved and deployed, you can use them depending on the HTTP Method defined in the custom query

• GET & DELETE methods will use the query string params to pass the values for the variables in the request URL. e.g.

  ${API_URL}/custom/query?id=1

• POST, PATCH & PUT methods will use values for the variables specified in the request body, assuming the body is a valid JSON:

{
  "id": 1,
  "anotherParameter": "Here"
}

Important considerations

• Variables do not need to be wrapped between single or double quotes for string datatypes, as we do the right parsing in our back end.

## Wrong
SELECT * FROM "Users" where id = '{{ id }}'

## Correct
SELECT * FROM "Users" where id = {{ id }}

• SQL Queries run as Parametrized Queries, meaning queries are protected from SQL Injection.

• Supported variable types are:

  • Int

  • String

  • Array

  • Boolean

  • Float

• A List variables purpose is to provide a list of values to be spread as the different elements of an array to be used in an IN clause in SQL, so that your queries can look like this:

SELECT * FROM users WHERE id IN {{ ids }}

## Can turn into
SELECT * FROM users where id IN ($id1, $id2, ...)