Deep Populate: Simplifying Multi-Database Data Access

8 Database Support Out Of The Box

Transform Complex Database Joins Into Simple API Requests

Deep Populate revolutionizes how developers handle complex relational data by fetching nested information from multiple databases with a single API call. No more writing intricate JOIN queries or managing multiple database connections manually.

What Makes Deep Populate Different?

Traditional database queries require developers to write complex JOIN statements or make multiple API calls to gather related data. Deep Populate eliminates this complexity by automatically creating a network of relationships across multiple database systems, returning comprehensive nested data structures in one request.

Before Deep Populate:

-- Multiple queries needed
SELECT * FROM persons WHERE name = 'Kishan';
SELECT * FROM streets WHERE id = person.street_id;
SELECT * FROM areas WHERE id = street.area_id;
-- ... and so on for 8+ more queries

With Deep Populate:

// For Schema defined Deep populate
/api/schema/user-path/instance/database/table?deep=[{s_key:"state_id"}]
                            
                                  OR
                                
// To custom Deep populate or override the default schema relation
/api/schema/user-path/instance/database/table?deep=[{s_key:"state_id",t_instance:"oracle",t_db:"inventory",t_col:"states",t_key:"id"}]

Why Deep Populate Makes Cross-Database Data Retrieval Easier

Eliminate N+1 Query Problems

The notorious N+1 query problem disappears when you can fetch all related data in one optimized request. Deep Populate handles the complex query optimization behind the scenes, dramatically reducing database load and improving application performance.

Cross-Database Relationship Management

Where traditional ORMs struggle with multi-database or cross-database resource retrieval, API Maker can over come that limitation with the support of 8 database including both SQL and No-SQL databases including MongnoDB, PostgreSQL, MySQL many other which you can check here.

Automatic Performance Optimization

Built-in query optimization ensures that even complex multi-level relationships execute efficiently. The system intelligently batches queries, uses appropriate indexes, and implements caching strategies to maintain fast response times.

How Deep Populate Works

The Relationship Chain Concept

Database relations are defined at the time of schema creation, When the user targets a specific field via a request, API Maker travels to the database, retrieves the data and wraps the content into a single json response object. This allows API Maker to build relations between different database instances without any limitation.

Let's say if the user does not want to define a schema and wants dynamic cross-database data retrieval or wants to override the default relation, the s_key and t_key properties in the deep-populate parameter object are used in this scenario. To learn more about this feature, click here.

Example Relationship Chain:

 Person → Street → City → Country

Each arrow represents a foreign key relationship that Deep Populate resolves automatically, even when the data spans different database systems.

Sample Request Object With Deep Populated Data:

Deep Populate requests use a nested JSON structure that mirrors your data relationships:

{
    "find": { "person_name": "John" },
    "deep": [
        {
            "s_key": "street_id",
            "t_key": "id",
            "t_table": "streets",
            "deep": [
                {
                    "s_key": "city_id",
                    "t_key": "id",
                    "t_table": "cities",
                    "deep": [
                        {
                            "s_key": "country_id",
                            "t_key": "id",
                            "t_table": "countries"
                        }
                    ]
                }
            ]
        }
    ]
}

This structure tells API Maker exactly how to traverse your data relationships, regardless of which databases contain each piece of information.

Sample Response Object With Deep Populated Data:

{
    "person_name": "John",
    "streets": {
        "id": 5,
        "name": "Main Street",
        "cities": {
            "id": 101,
            "name": "New York",
            "countries": {
                "id": 1,
                "name": "USA"
            }
        }
    }
}

Advanced Features for Enterprise Applications

Streaming for Large Datasets

When dealing with large result sets, The stream APIs can be used to optimize the api response content, The streams can help by providing the content of the request into chunks without loading the data into memory which will prevent memory overload in larger data infrastructures.

Benefits Of Using Deep Populate With Streams:

  • Memory-efficient processing of large result sets
  • Real-time data delivery for responsive user interfaces
  • Automatic pagination handling for complex nested queries
  • Scalable architecture that grows with your data volume

Auto-Caching Layer

The built-in caching system recognizes patterns in Deep Populate requests and automatically caches frequently accessed data combinations. This intelligent caching reduces database load and improves response times for common query patterns.

Caching Features:

  • Automatic cache invalidation when source data changes
  • Configurable cache duration per database or collection
  • Memory-efficient cache storage with intelligent eviction policies
  • Cross-database cache coherency for consistent results

Schema-Based Relationship Definitions

Frequently used Database relationships can be defined into api maker schemas which allow user to request the Data by providing the name of the field in the request which makes cross-database data retrieval faster and easier. Visit this page for more detail.

// Simplified request with pre-configured relationships via database schema
{
  "find": { "person_name": "Kishan" },
  "deep": ["full_address_chain"]
}

Integration with Modern Development Workflows

RESTful API Compatibility

Deep Populate works seamlessly with standard REST API patterns, extending traditional GET requests with powerful relationship traversal capabilities. Your existing API clients require no modifications to benefit from Deep Populate functionality.

GraphQL-Style Flexibility

While maintaining REST simplicity, Deep Populate provides GraphQL-like flexibility for specifying exactly which related data you need. This approach combines the best aspects of both API techniques without requiring a complete architectural change.

Microservices Architecture Support

In microservices environments, Deep Populate can aggregate data from services that manage different databases, providing a unified data access layer that simplifies client application development.

Development and Testing Tools

API Maker provides comprehensive testing tools for Deep Populate queries, including query visualization, performance profiling, and relationship validation. These tools help developers understand query execution paths and optimize data access patterns.

Migration from Existing Systems

While migrating from other existing systems, People often encounter the problem of defining the relations in the database which can be quite painful, In API Maker the Database relations can be created with one click and the user can start using features like Deep Populate without any extra hustle.

Multi-Database Architecture Support

The feature works seamlessly across API Maker's supported database ecosystem, Database relations between SQL to SQL are possible as well as SQL to NoSQL:

Relational Databases:

Document and Distributed Databases:

  • MongoDB for flexible document-based data models
  • TiDB for distributed SQL processing
  • Percona XtraDB for high-performance MySQL clustering

Detailed Platform Comparison:

How Deep Populate Stacks Up Against the Competition

  • When building modern applications, developers often choose between established backend platforms like Supabase, Firebase, Appwrite, or GraphQL implementations. Here's how Deep Populate compares across key features:
Feature Related To Getting Data API Maker Supabase Firebase Appwrite
Cross-Database Queries ✅ Native support across 8+ databases ❌ Single PostgreSQL only ❌ Single Firestore only ❌ Single database per project
Real-time Multi-DB Relations ✅ Live updates across databases ⚠️ PostgreSQL only ⚠️ Firestore only ⚠️ Single database
SQL + NoSQL Integration ✅ Seamless MySQL→MongoDB queries ❌ PostgreSQL only ❌ NoSQL only ⚠️ Limited SQL support
Unlimited Nesting Depth ✅ Person→Street→City→Country→... ⚠️ Manual JOIN complexity ❌ Limited subcollection depth ⚠️ Manual relationship handling
Auto Query Optimization ✅ Built-in batching & caching ⚠️ Manual optimization needed ⚠️ Limited optimization tools ⚠️ Basic optimization
Schema-less Dynamic Queries ✅ Override relations on-the-fly ❌ Fixed schema required ❌ Collection structure fixed ❌ Schema-dependent
Multi-Database Transactions ✅ Cross-database types ACID support ❌ Single database only ❌ Limited transaction scope ❌ Single database only
Enterprise Database Support ✅ Oracle, SQL Server, MySQL, etc. ❌ PostgreSQL only ❌ Firestore only ⚠️ Limited enterprise options

Supabase: PostgreSQL Excellence, Limited Scope

Supabase excels at PostgreSQL management but struggles with multi-database scenarios.

Supabase Limitations:

  • Single PostgreSQL database per project
  • Complex JOINs require manual SQL optimization
  • No cross-database relationship support
  • Limited to PostgreSQL's data types and constraints

Deep Populate Advantages:

  • Query across PostgreSQL, MongoDB, MySQL simultaneously
  • Automatic optimization across different database engines
  • No SQL knowledge required for complex relationships
  • Support for 8+ database types in one query

Firebase: Great for Simple Apps, Limited for Enterprise

Firebase's Firestore is excellent for rapid prototyping but hits walls with complex data.

Firebase Limitations:

  • No true relational queries (only subcollections)
  • Expensive for read-heavy applications
  • Limited to NoSQL document model
  • Complex pricing structure for large datasets

Deep Populate Advantages:

  • True relational queries across any database type
  • Predictable pricing model
  • Mix relational and document data in single queries
  • Built-in caching reduces read costs

Why API Maker Doesn't Need GraphQL Support

Deep Populate: The GraphQL Alternative That Actually Works

Many developers ask why API Maker doesn't offer GraphQL support. The answer is simple: Deep Populate provides all the benefits of GraphQL without any of the complexity, overhead, or limitations.

GraphQL was created to solve the problems of over-fetching data and making multiple API calls. Deep Populate solves these same problems with better performance and without having to learn unnecessary material about how to retrieve data from a table.

The GraphQL Problem Statement

GraphQL emerged to address several key issues with traditional REST APIs:

  • Over-fetching: Getting more data than needed
  • Under-fetching: Making multiple requests for related data
  • API Versioning: Managing schema changes over time
  • Frontend Flexibility: Letting clients specify exactly what data they need

Deep Populate solves all these problems better than GraphQL.

Ready to transform your data access layer? Explore API Maker's Deep Populate documentation see how it can simplify your next project.


FAQ's

1. How many database levels can Deep Populate handle in a single request?

Deep Populate supports unlimited nesting levels. You can traverse relationships from Person → Street → Area → City → State → Country → Continent → Planet → Galaxy and beyond. However, for optimal performance, we recommend keeping queries under 10 levels deep.

2. What's the difference between schema-based and custom Deep Populate requests?

Schema-based requests use pre-defined relationships (deep: ["full_address_chain"]) for simplicity and performance. Custom requests let you specify exact relationships on-the-fly with full control over source and target databases. Use schemas for common patterns and custom for one-off queries.

3. Can I use Deep Populate with real-time data or webhooks?

Absolutely. Deep Populate works with API Maker's real-time features. You can set up webhooks that trigger when any data in your relationship chain changes, and use streaming APIs to get live updates of nested data structures.

4. Does Deep Populate support filtering and sorting on nested data?

Yes. You can apply filters, sorting, and pagination at any level of your deep populate query. For example, you can get a person's address while only including cities with population > 100,000, sorted by name.

5. What happens if one of the databases in my deep query is unavailable?

API Maker handles database failures gracefully. If a database is unavailable, the query returns partial results up to the point of failure, along with error details. You can configure fallback behavior and retry logic for critical data paths.

6. How does Deep Populate handle performance with large datasets?

Deep Populate includes automatic query optimization, intelligent batching, and built-in caching. For very large datasets, you can use streaming APIs to process results in chunks without loading everything into memory.

7. Can Deep Populate work across different database types in one query?

Yes, absolutely. Deep Populate seamlessly connects data across all supported databases - MySQL, PostgreSQL, MongoDB, Oracle, SQL Server, MariaDB, TiDB, and Percona XtraDB. You can start with a MongoDB document and traverse to PostgreSQL tables without any additional configuration.


Learn more about API Maker's low-code backend platform and other powerful features at apimaker.dev


Live example with video is given below for deep populate across database types

MongoDB

Find data from mongodb

MySQL

Get city data from mysql

SQL Server

Get states data from sql server database

Maria DB

Get countries data from maria database

Oracle DB

Get continent data from database

PostgreSQL DB

Get planets data from postgresql database

Ti DB

Get planets data from TI database

Percona XtraDB

Get planets data from Percona Xtra database

  • One GET API call can get data from N number of different types of databases with N number of data complexity.
  • Stream APIs can stream huge amount of data.
  • In our custom APIs, we can get huge data as one by one object so we can process them one by one.
  • If caching is enabled in any table/collection, it can leverage that and speed up the process.
8 Database support request body

{
    "find": {
    "person_name": "Kishan"
    },
    "deep": [
    {
        "s_key": "street_id",
        "t_key": "id",
        "t_table": "streets",
        "deep": [
        {
            "s_key": "area_id",
            "t_key": "id",
            "t_table": "areas",
            "deep": [
            {
                "s_key": "city_id",
                "t_key": "id",
                "t_table": "cities",
                "deep": [
                {
                    "s_key": "state_id",
                    "t_key": "id",
                    "t_table": "states",
                    "deep": [
                    {
                        "s_key": "country_id",
                        "t_key": "id",
                        "t_table": "countries",
                        "deep": [
                        {
                            "s_key": "continent_id",
                            "t_key": "id",
                            "t_table": "continents",
                            "deep": [
                            {
                                "s_key": "planet_id",
                                "t_key": "id",
                                "t_table": "planets",
                                "deep": [
                                {
                                "s_key": "galexy_id",
                                "t_key": "id",
                                "t_table": "galaxies"
                                }
                                ]
                            }
                            ]
                        }
                        ]
                    }
                    ]
                }
                ]
            }
            ]
        }
        ]
    }
    ]
}

                                                            
Response from 8 different databases

{
    "person_name": "Kishan",
    "street_id": { // from MongoDB
        "id": 12,
        "street_name": "TIRUPATI",
        "area_id": { // from MySQL
            "id": 24,
            "area_name": "RANIP",
            "city_id": { // from SQL_SERVER
                "id": 382480,
                "city_name": "AHMEDABAD",
                "state_id": { // from MariaDB
                    "id": 91,
                    "state_name": "GUJARAT",
                    "country_id": { // from Oracle
                        "id": 4,
                        "country_name": "INDIA",
                        "continent_id": { // from PostgreSQL
                            "id": 3,
                            "countinent_name": "ASIA"
                            "planet_id": { // from Ti DB
                                "id": 2,
                                "planet_name": "EARTH"
                                "galexy_id": { // from Percona XtraDB
                                    "id": 1,
                                    "galaxies_name": "Milky Way"
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}