Mongo Storage

Mongo Storage allows GlueSQL to use MongoDB as a backend for SQL queries. It enables features such as joins and aggregations on top of MongoDB collections while optionally enforcing GlueSQL's schema system.

Prerequisites

Install and run MongoDB.

1. Using Docker

docker run --name mongo-glue -d -p 27017:27017 mongo

2. Local Installation

Follow the official MongoDB installation guide.

Example

Below is a minimal example showing how to execute SQL statements on MongoDB using GlueSQL in Rust:

use gluesql::{prelude::Glue, mongo_storage::MongoStorage};

#[tokio::main]
async fn main() {
    let conn_str = "mongodb://localhost:27017";
    let storage = MongoStorage::new(conn_str, "my_db").await.unwrap();
    let mut glue = Glue::new(storage);

    let sql = "
        CREATE TABLE Foo (id INT, name TEXT);
        INSERT INTO Foo VALUES (1, 'Alice'), (2, 'Bob');
        SELECT * FROM Foo;
    ";

    let payloads = glue.execute(sql).await.unwrap();
    println!("{:#?}", payloads);
}

After running the above code you will have a Foo collection in MongoDB populated with two documents. You can continue to query it using SQL syntax:

SELECT name FROM Foo WHERE id > 1;

| name |
|------|
| Bob  |

Summary

Mongo Storage integrates MongoDB with GlueSQL so you can work with your MongoDB data using standard SQL. Ensure MongoDB is running before connecting.