Query Language

Powerful query syntax for filtering and finding documents

Overview

jasonisnthappy includes a custom query language for filtering documents. The query language supports comparison operators, logical operators, field existence checks, and array operations. All queries are evaluated efficiently using the database's indexing system.

Comparison Operators

Use comparison operators to filter documents based on field values.

Greater Than (>)

age > 30

Matches documents where the age field is greater than 30.

Greater Than or Equal (>=)

age >= 30

Matches documents where the age field is greater than or equal to 30.

Less Than (<)

age < 30

Matches documents where the age field is less than 30.

Less Than or Equal (<=)

age <= 30

Matches documents where the age field is less than or equal to 30.

Equals (is)

name is "Alice"
status is true
count is 42
value is null

Matches documents where the field exactly equals the specified value. Supports strings, numbers, booleans, and null.

Not Equals (is not)

name is not "Bob"

Matches documents where the field does not equal the specified value.

Logical Operators

Combine multiple conditions using logical operators.

AND

age > 30 and city is "NYC"

Both conditions must be true for the document to match.

OR

age < 18 or age > 65

At least one condition must be true for the document to match.

NOT

not age > 30

Negates a condition. The document matches if the condition is false.

Parentheses for Grouping

(age < 18 or age > 65) and status is "active"

Use parentheses to control evaluation order and create complex logic.

Field Operators

Exists

email exists

Matches documents that have the specified field (field is not null).

Not Exists

email not exists

Matches documents that do not have the specified field (field is null or missing).

Boolean Shorthand

active

Shorthand for active is true. Matches documents where the field is true.

Array Operators

Query documents with array fields using specialized array operators.

Has

tags has "javascript"

Matches documents where the tags array contains the value "javascript".

Has Any

tags has any ["javascript", "typescript", "rust"]

Matches documents where the tags array contains at least one of the specified values.

Has All

tags has all ["javascript", "typescript"]

Matches documents where the tags array contains all of the specified values.

Nested Fields

Access nested object fields using dot notation.

user.address.city is "NYC"
user.profile.age > 30
settings.notifications.email is true

Use dots to traverse nested objects and query deeply nested fields.

Query Examples

Simple Queries

// Find users older than 30
age > 30

// Find active users
status is "active"

// Find users with email addresses
email exists

Complex Queries

// Find active users in NYC older than 25
age > 25 and city is "NYC" and status is "active"

// Find users who are either minors or seniors
age < 18 or age > 65

// Find users with specific tags
tags has any ["premium", "verified"]

Nested Field Queries

// Find users in NYC with verified profiles
user.address.city is "NYC" and user.profile.verified is true

// Find users with high engagement scores
metrics.engagement.score > 80 and metrics.active is true

Combined Queries

// Find premium users in specific cities who are active
(city is "NYC" or city is "SF") and subscription is "premium" and status is "active"

// Find users who don't have certain attributes
not (tags has "spam") and not (status is "banned")

// Complex filtering with multiple conditions
age >= 18 and age <= 65 and (income > 50000 or education is "graduate") and employment is "employed"

Usage in Code

use jasonisnthappy::Database;

fn main() -> jasonisnthappy::Result<()> {
    let db = Database::open("my.db")?;
    let collection = db.collection("users");

    // Find with query
    let results = collection.find("age > 30 and city is \"NYC\"")?;

    // Count matching documents
    let count = collection.count_with_query("status is \"active\"")?;

    // Find one document
    let user = collection.find_one("email is \"alice@example.com\"")?;

    Ok(())
}
from jasonisnthappy import Database

with Database.open("my.db") as db:
    collection = db.collection("users")

    # Find with query
    results = collection.find('age > 30 and city is "NYC"')

    # Count matching documents
    count = collection.count_with_query('status is "active"')

    # Find one document
    user = collection.find_one('email is "alice@example.com"')
const { Database } = require('jasonisnthappy');

const db = Database.open('my.db');
const collection = db.collection('users');

// Find with query
const results = collection.find('age > 30 and city is "NYC"');

// Count matching documents
const count = collection.countWithQuery('status is "active"');

// Find one document
const user = collection.findOne('email is "alice@example.com"');

db.close();
package main

import (
    "github.com/sohzm/jasonisnthappy-go"
)

func main() {
    db, _ := jasonisnthappy.Open("my.db")
    defer db.Close()

    collection, _ := db.Collection("users")

    // Find with query
    results, _ := collection.Find("age > 30 and city is \"NYC\"")

    // Count matching documents
    count, _ := collection.CountWithQuery("status is \"active\"")

    // Find one document
    user, _ := collection.FindOne("email is \"alice@example.com\"")
}

Performance Tips