README.md

GoQrius

Warning

GoQrius is under heavy development.

A powerful filter query parameter implementation based on Microsoft API Guidelines and OData filter for filtering and querying data with expressive syntax.

Note

This repository only contains the lexer-parser.

To check the current data-layer implementations, check Implementations.

🚀 Features

GoQrius provides a comprehensive set of logical operators for building complex filter expressions:

Comparison Operators

• eq: to check for equality, e.g. name eq 'John'.
• ne: to check not equality, e.g. name ne 'John'.
• gt: to check greater than, e.g. age gt 18.
• ge: to check greater than or equal, e.g. age ge 18.
• lt: to check lower than, e.g. age lt 21.
• le: to check lower than or equal, e.g. age le 21.

Logical Operators

• not: to negate the next check, e.g. not name eq 'John'.
• and: to AND concatenate conditions, e.g. name eq 'John' and age gt 18
• or: to OR concatenate conditions, e.g. age le 18 or age ge 65

📚 Examples

Imagine the following users

Id	Name	Surname	Age	Email
1	John	Doe	20	john.doe@example.com
2	Jane	Doe	10
3	Alice	Smith	66	alice.smith@example.com
4	Bob	Smith	30

Then it's expected to filter the following conditions:

Filter	John(1)	Jane(2)	Alice(3)	Bob(4)
name eq 'John'	✅	❌	❌	❌
name ne 'John'	❌	✅	✅	✅
not name eq 'John'	❌	✅	✅	✅
age gt 18 and age lt 65	✅	❌	❌	✅
age le 18 or age gt 65	❌	✅	✅	❌
email eq null	❌	✅	❌	✅

🔧 Implementations

GoQrius is designed to be easily integrated into your REST API endpoints. By using:

filter := "name eq 'John'" // e.g. value retrieved from a query parameter. 
e, err := goqrius.Parse(filter)
if err != nil {
 ...
}
...

You get the GoQrius expression that can be transformed to a filtering clause in your data layer.

The current data layers implementations for GoQrius are:

• GormGoQrius