Does this send my query anywhere?

No. Parsing and conversion run entirely in your browser using a hand-written SQL subset parser.

Does it support real SQL syntax, like joins or subqueries?

No. This is a best-effort converter for a simple SELECT statement's columns, FROM table, WHERE conditions, ORDER BY, and LIMIT. JOINs, subqueries, GROUP BY, and aggregate functions aren't supported and are reported as an error rather than silently mishandled.

Which WHERE operators are supported?

=, !=, <>, >, =, <=, combined with AND/OR (AND binds tighter than OR, matching normal SQL precedence). Parenthesized groups within WHERE aren't supported.

What happens to SELECT * vs. specific columns?

SELECT * produces a find() call with just the query object. Selecting specific columns adds a second find() argument as a MongoDB projection, e.g. { col1: 1, col2: 1 }.

SQL to NoSQL Query Converter - SQL to MongoDB Online

Overview

Introduction

Moving a query from a relational database to MongoDB means re-learning how WHERE, ORDER BY, and LIMIT map onto find(), sort(), and limit().

This tool converts a simple SQL SELECT statement into an equivalent MongoDB-style query string directly in your browser, with no server round trip.

What Is SQL to NoSQL Query Converter?

A hand-written parser for a practical subset of SQL SELECT syntax: column lists (including *), a single table name, WHERE conditions joined by AND/OR, ORDER BY, and LIMIT.

It produces a MongoDB shell-style query string using find(), sort(), and limit(), with a projection as find()'s second argument when specific columns were selected.

How SQL to NoSQL Query Converter Works

The parser walks the statement clause by clause: it splits out the column list, table name, WHERE clause, ORDER BY column/direction, and LIMIT count using a small hand-written grammar, not a general-purpose SQL engine.

WHERE conditions are split on OR first, then AND within each OR-group, matching SQL's usual AND-before-OR precedence, and each condition's comparison operator maps to the matching MongoDB query operator ($gt, $gte, $lt, $lte, $ne).

When To Use SQL to NoSQL Query Converter

Use it when prototyping a MongoDB migration and you want a quick starting point for translating a handful of familiar SQL queries.

It's also useful for learning how SQL WHERE clauses map onto MongoDB's query operators without looking each one up individually.

Often used alongside JavaScript Formatter and JavaScript Validator.

Features

Advantages

Runs entirely client-side, so queries never leave your browser.
Handles the operators and clauses developers reach for most often: comparisons, AND/OR, ORDER BY, and LIMIT.
Produces a projection argument automatically when specific columns are selected, rather than always fetching every field.

Limitations

This is an explicitly best-effort subset converter, not a full SQL engine: it has no support for JOINs, subqueries, GROUP BY, aggregate functions, or parenthesized WHERE groups, and reports a clear error rather than guessing at those.
WHERE clauses mixing AND and OR are resolved with standard AND-before-OR precedence and no way to override it with parentheses, since parenthesized grouping isn't parsed.
Column and table names must be simple identifiers; qualified names like table.column or quoted identifiers aren't supported.

Examples

WHERE with AND, ORDER BY, and LIMIT, selecting specific columns

Input

SELECT col1, col2 FROM table WHERE col = 'value' AND col2 > 5 ORDER BY col3 LIMIT 10

Output

db.table.find({ col: "value", col2: { $gt: 5 } }, { col1: 1, col2: 1 }).sort({ col3: 1 }).limit(10)

The WHERE conditions merge into one object, the selected columns become a projection, and ORDER BY/LIMIT become chained sort()/limit() calls.

SELECT * with no WHERE clause

Input

SELECT * FROM users

Output

db.users.find({})

With no WHERE clause and no specific columns, the query object is empty and no projection argument is added.

Best Practices & Notes

Best Practices

Keep queries to a single table; this tool has no notion of joining collections.
Use simple, unqualified column and table names so the parser doesn't misread them as part of a WHERE expression.
Double-check the generated operators against MongoDB's query operator docs before relying on them in production code.

Developer Notes

The SQL grammar is parsed with hand-written regex-based clause splitting (no external SQL parser library), and the MongoDB query object is rendered with a small custom stringifier that mimics mongosh's shell syntax rather than strict JSON.

SQL to NoSQL Query Converter Use Cases

Getting a first-pass MongoDB query while migrating a small SQL-based service
Learning how a specific SQL WHERE clause maps onto MongoDB's comparison operators
Quickly sketching a find() call from a familiar SELECT statement during a code review discussion

Common Mistakes

Pasting a query with a JOIN or subquery and expecting a correct translation; those aren't supported and are reported as an error instead.
Assuming parentheses in a WHERE clause change evaluation order; they aren't parsed, so only the default AND-before-OR precedence applies.

Tips

If the converter reports an unsupported clause, simplify the query to the supported subset (columns, WHERE, ORDER BY, LIMIT) and translate the rest by hand.
Run the output through the JSON Formatter if you want to pretty-print just the query object apart from the find()/sort()/limit() chain.

SQL to NoSQL Query Converter