README.md

SQL queries on top of MongoDB

It is a programmatic tool that helps you write SELECT queries on top of MongoDB collections.

How to run the project

1. Install all dependencies

  npm install

2. Building SQL Grammar

  npm run sql-mongo

3. Formulating the query API Docs

4. Running the application to query

npm run query

API Reference

1. Import the parser

import { Parser } from "./models/Parser";

2. Create a new parser object

  const parser = new Parser(url)

Parameter	Type	Description
url	string	Required. Connection URL of MongoDB database

NOTE: The connection url must contain database name

For example

mongodb+srv://url/sample_database

3. Call the connect method to connect to the MongoDB instance

await parser.connect();

4. Use the query method to query from the collection

 parser.query(statement, callback);

Parameter	Type	Description
statement	string	Required. SQL select statement
callback	function	Required. Callback function to get the results

Query Semantics

SELECT [ * | column name(s) ]
FROM [ collection name ]
[WHERE condition]

Column

At least one of them is required

Parameter	Description
*	Select all columns
column1, column2...	Select one or more specific columns

Collection Name

At least one collection name is required

Parameter	Description
users	Name of the collection to perform query

Condition in where clause

Conditions with logical and range operators to satisfy for selecting documents

column1=SQL and column2>=n100 or column3 < N200

NOTE: Prefix numbers with n or N. Else they will be parsed as strings

Conditions for querying subdocuments

Use the dot annotation to query subdocuments

WHERE customer.name = Tom and customer.age > N28

Operators

Supported logical and range operators

Parameter	Type
AND	Logical
OR	Logical
<	Range
>	Range
=	Range
<=	Range
>=	Range