serhiihoroshko/mongo-demo

• Required mongodb: mongod command
• Windows, Develop: npm run windowsDebug command

Modelling Relationships:

Trade off between query performance vs consistency

1. Using References (Normalization) -> CONSISTENCY

let author = {
    name: 'Travis Scott'
}

let book = {
    author: 'id'
}

2. Using Embedded Documents (Denormalization) -> PERFORMANCE

let book = {
    author: {
        name: 'Travis Scott'
    }
}

3. Hybrid approach mongodb (best for small shops)

let author = {
    name: 'Travis Scott'
    ... // and other prorerties
}

let book = {
    author: {
        id: 'referral',
        name: 'Travis Scott'
    }
}

Comparison Query Operators:

• eq (equal),
• ne (not equal),
• gt (greather than)
• gte (greathe than or equal to)
• lt (less than)
• lte (less than or equal to)
• in
• nin (not in)

Logical Query Operators

• or
• and

Regular Expression

$regex manual

Examples { <field>: /pattern/<options> }:

• Start with Tolkien .find ({ author: /^Tolkien/ })
• Ends with Tolkien .find ({ author: /Tolkien$/i })
• Contain Tolkien .find ({ author: /.*Tolkien.*/ })

Counting

.count();