Convert SQL WHERE with Comparison Operators to MongoDB

Comparison Operators: SQL to MongoDB

SQL WHERE clauses with comparison operators translate directly to MongoDB query operators inside the filter document passed to find().

Example SQL

SELECT * FROM products
WHERE price >= 100 AND stock > 0

Generated MongoDB Query

db.products.find({
  price: { $gte: 100 },
  stock: { $gt: 0 }
})

Operator Mapping Table

SQL Operator	MongoDB Operator	Example
=	implicit / $eq	{ status: "active" }
!= or <>	$ne	{ status: { $ne: "deleted" } }
>	$gt	{ age: { $gt: 21 } }
>=	$gte	{ price: { $gte: 100 } }
<	$lt	{ quantity: { $lt: 5 } }
<=	$lte	{ rating: { $lte: 3 } }

Implicit AND

When multiple conditions are placed in the same filter document (as shown above), MongoDB treats them as an implicit AND. This is equivalent to SQL's AND keyword and is the most common pattern for combining conditions.

Equality Shorthand

For equality checks, MongoDB uses a shorthand where the value is placed directly: { status: "active" } instead of { status: { $eq: "active" } }. Both forms work, but the shorthand is more idiomatic and widely used.

Type-Aware Comparisons

MongoDB comparisons are type-aware. Comparing a string field with a number will not produce matches, unlike some SQL databases that perform implicit type casting. Ensure your filter values match the stored data types.