17. Databases Part 2: SQLite & Supabase | FlutterFlow University Expert Training

[@Jeepingtop]

a wealth of knowledge... and I really like the voice acting. you are really Pro.💪 I wish you prosperity in your business, until your second milk teeth😊

[@johnieboy6760]

How to get the lastInsertedIdRow in sqlite. How to link foreign keys to a row created.

[@rabeezley]

Will SQLite be available for the web in Flutterflow in the near future?

[@YannBula]

x2, commenting to see future replies

[@rehaanu]

How do we add offline capabilities aswell as online

[@rabeezley]

I would be very interested in this also. Seems like local first is the way to go.

[@MrIzeQ]

1. Manual Synchronization (Custom Logic):
How it works:
You write custom code (e.g., in Flutter/Dart for a FlutterFlow app) to handle the synchronization logic between the local and online databases.
You decide when to sync, what data to sync, and how to resolve conflicts.
Steps:
Local Database (e.g., SQLite): Set up your local database using a package like sqflite in Flutter.
Online Database (e.g., PostgreSQL, Firebase): Set up your online database.
Synchronization Logic:
Initial Data Download: When the app starts (or on-demand), fetch data from the online database and populate the local database.
Track Changes: Implement a mechanism to track changes made locally (e.g., using a "dirty" flag or a separate "changes" table in SQLite).
Upload Changes: Periodically or when an internet connection is available, send local changes to the online database.
Download Changes: Fetch changes from the online database and update the local database accordingly.
Conflict Resolution: Implement logic to handle conflicts that may arise when the same data is modified both locally and online (e.g., "last write wins," "server wins," or a more sophisticated merging strategy). You can use timestamps for this.
API Calls: Use FlutterFlow's API call features or write custom code to interact with your online database's API.
Pros:
Full Control: You have complete control over the synchronization process.
Flexibility: You can tailor the logic to your specific needs.
Cons:
Complex: Requires significant development effort to write and maintain the synchronization code.
Error-Prone: More prone to errors and inconsistencies if not implemented carefully.
Difficult to Scale: Can become very complex as your data model and synchronization requirements grow.
2. Using a Synchronization Library/Framework:
How it works:
Leverage a library or framework that simplifies the synchronization process.
These tools often provide higher-level abstractions for managing local and online data, tracking changes, and handling conflicts.
Examples:
WatermelonDB (JavaScript/React Native): A reactive database framework that has synchronization capabilities. It is based on SQLite.
Realm (Mobile): A mobile database that offers a Sync feature to synchronize data with MongoDB Atlas.
Couchbase Lite (Mobile): A NoSQL embedded database with built-in synchronization capabilities using Couchbase or other compatible backends.
Firebase (with Offline Persistence): Firebase's Realtime Database and Cloud Firestore have built-in offline persistence and synchronization features. When you enable offline persistence, the Firebase SDK automatically caches data locally and handles synchronization when the device comes online.
Pros:
Faster Development: Reduces the amount of custom synchronization code you need to write.
Less Error-Prone: Libraries are typically well-tested and handle many of the complexities of synchronization for you.
Easier to Maintain: Simpler to update and maintain compared to manual synchronization.
Cons:
Less Control: You might have less control over the specific details of the synchronization process compared to writing it manually.
Vendor Lock-in: You become dependent on the chosen library or framework.
Learning Curve: You need to learn how to use the specific library or framework.
3. Using a Backend-as-a-Service (BaaS) with Offline Features:
How it works:
Some BaaS providers offer built-in offline persistence and synchronization as part of their platform.
You interact with the BaaS provider's SDK, and they handle the synchronization logic for you.
Examples:
Firebase (Realtime Database and Cloud Firestore): As mentioned, Firebase offers offline persistence and automatic synchronization.
AWS Amplify DataStore: Provides a programming model for leveraging shared and distributed data without writing additional code for offline or online scenarios.
Pros:
Easiest to Implement: Often the simplest approach, as the BaaS provider handles most of the complexity.
Fully Managed: You don't need to manage any servers or databases.
Cons:
Vendor Lock-in: You become heavily dependent on the BaaS provider.
Cost: BaaS pricing can be more expensive than managing your own backend, especially as your app scales.
Limited Customization: You might have less flexibility to customize the synchronization logic compared to other approaches.
Choosing the Right Approach:
Manual Synchronization: Suitable for projects with very specific or complex synchronization needs where you require fine-grained control. Only recommended if you have the expertise and resources to implement and maintain it correctly.
Synchronization Library/Framework: A good balance between control and development speed. Suitable for moderately complex projects where you want to simplify the synchronization process but still have some control.
BaaS with Offline Features: The easiest option if you want a fully managed solution and are comfortable with the vendor lock-in and potential costs. Ideal for projects where development speed and ease of use are top priorities.
Example (Conceptual - using Firebase in FlutterFlow):
Enable Offline Persistence in Firebase:
In your Firebase console, enable offline persistence for either the Realtime Database or Cloud Firestore.
Use Firebase SDK in FlutterFlow:
Add the necessary Firebase packages (firebase_core, cloud_firestore or firebase_database) to your pubspec.yaml.
Initialize Firebase in your FlutterFlow app's main entry point.
Interact with Firebase:
Use FlutterFlow's visual interface to build your UI.
Use custom actions or functions to interact with the Firebase SDK, which will automatically handle local caching and synchronization.
Example Code (Illustrative - adding a patient to Firestore with offline persistence):
import 'package:cloud_firestore/cloud_firestore.dart';
Future addPatient(String firstName, String lastName, String dob) async {
try {
await FirebaseFirestore.instance.collection('patients').add({
'first_name': firstName,
'last_name': lastName,
'dob': dob,
'timestamp': FieldValue.serverTimestamp(), // Important for conflict resolution
});
} catch (e) {
print("Error adding patient: $e");
}
}
Use code with caution.
Dart
Important Considerations:
Conflict Resolution: Carefully design your conflict resolution strategy. Common approaches include:
Last Write Wins: The last modification overwrites previous changes.
Server Wins: The data from the online database always takes precedence.
Client Wins: The local changes are always kept.
Custom Merge Logic: You write code to merge the changes based on specific rules. Using timestamps can help determine which data is newer.
Data Modeling: Design your data model to support synchronization efficiently. Consider adding fields like:
last_updated_at (timestamp): To track when data was last modified.
is_deleted (boolean): To handle deletions logically (soft deletes instead of hard deletes).
server_id (string): To store the ID of the corresponding record in the online database (if applicable).
Testing: Thoroughly test your synchronization logic to ensure data consistency and prevent data loss. Simulate offline and online scenarios, and test various conflict resolution cases.
Security: Secure both your local and online databases appropriately. Use encryption for sensitive data stored locally, and implement proper authentication and authorization for your online database.
By carefully considering your project's requirements, choosing the right approach, and implementing robust synchronization logic, you can successfully build applications that leverage the benefits of both local and online databases, providing a seamless and efficient user experience.

[@MrIzeQ]

@@rabeezley 1. Manual Synchronization (Custom Logic):
How it works:
You write custom code (e.g., in Flutter/Dart for a FlutterFlow app) to handle the synchronization logic between the local and online databases.
You decide when to sync, what data to sync, and how to resolve conflicts.
Steps:
Local Database (e.g., SQLite): Set up your local database using a package like sqflite in Flutter.
Online Database (e.g., PostgreSQL, Firebase): Set up your online database.
Synchronization Logic:
Initial Data Download: When the app starts (or on-demand), fetch data from the online database and populate the local database.
Track Changes: Implement a mechanism to track changes made locally (e.g., using a "dirty" flag or a separate "changes" table in SQLite).
Upload Changes: Periodically or when an internet connection is available, send local changes to the online database.
Download Changes: Fetch changes from the online database and update the local database accordingly.
Conflict Resolution: Implement logic to handle conflicts that may arise when the same data is modified both locally and online (e.g., "last write wins," "server wins," or a more sophisticated merging strategy). You can use timestamps for this.
API Calls: Use FlutterFlow's API call features or write custom code to interact with your online database's API.
Pros:
Full Control: You have complete control over the synchronization process.
Flexibility: You can tailor the logic to your specific needs.
Cons:
Complex: Requires significant development effort to write and maintain the synchronization code.
Error-Prone: More prone to errors and inconsistencies if not implemented carefully.
Difficult to Scale: Can become very complex as your data model and synchronization requirements grow.
2. Using a Synchronization Library/Framework:
How it works:
Leverage a library or framework that simplifies the synchronization process.
These tools often provide higher-level abstractions for managing local and online data, tracking changes, and handling conflicts.
Examples:
WatermelonDB (JavaScript/React Native): A reactive database framework that has synchronization capabilities. It is based on SQLite.
Realm (Mobile): A mobile database that offers a Sync feature to synchronize data with MongoDB Atlas.
Couchbase Lite (Mobile): A NoSQL embedded database with built-in synchronization capabilities using Couchbase or other compatible backends.
Firebase (with Offline Persistence): Firebase's Realtime Database and Cloud Firestore have built-in offline persistence and synchronization features. When you enable offline persistence, the Firebase SDK automatically caches data locally and handles synchronization when the device comes online.
Pros:
Faster Development: Reduces the amount of custom synchronization code you need to write.
Less Error-Prone: Libraries are typically well-tested and handle many of the complexities of synchronization for you.
Easier to Maintain: Simpler to update and maintain compared to manual synchronization.
Cons:
Less Control: You might have less control over the specific details of the synchronization process compared to writing it manually.
Vendor Lock-in: You become dependent on the chosen library or framework.
Learning Curve: You need to learn how to use the specific library or framework.
3. Using a Backend-as-a-Service (BaaS) with Offline Features:
How it works:
Some BaaS providers offer built-in offline persistence and synchronization as part of their platform.
You interact with the BaaS provider's SDK, and they handle the synchronization logic for you.
Examples:
Firebase (Realtime Database and Cloud Firestore): As mentioned, Firebase offers offline persistence and automatic synchronization.
AWS Amplify DataStore: Provides a programming model for leveraging shared and distributed data without writing additional code for offline or online scenarios.
Pros:
Easiest to Implement: Often the simplest approach, as the BaaS provider handles most of the complexity.
Fully Managed: You don't need to manage any servers or databases.
Cons:
Vendor Lock-in: You become heavily dependent on the BaaS provider.
Cost: BaaS pricing can be more expensive than managing your own backend, especially as your app scales.
Limited Customization: You might have less flexibility to customize the synchronization logic compared to other approaches.
Choosing the Right Approach:
Manual Synchronization: Suitable for projects with very specific or complex synchronization needs where you require fine-grained control. Only recommended if you have the expertise and resources to implement and maintain it correctly.
Synchronization Library/Framework: A good balance between control and development speed. Suitable for moderately complex projects where you want to simplify the synchronization process but still have some control.
BaaS with Offline Features: The easiest option if you want a fully managed solution and are comfortable with the vendor lock-in and potential costs. Ideal for projects where development speed and ease of use are top priorities.
Example (Conceptual - using Firebase in FlutterFlow):
Enable Offline Persistence in Firebase:
In your Firebase console, enable offline persistence for either the Realtime Database or Cloud Firestore.
Use Firebase SDK in FlutterFlow:
Add the necessary Firebase packages (firebase_core, cloud_firestore or firebase_database) to your pubspec.yaml.
Initialize Firebase in your FlutterFlow app's main entry point.
Interact with Firebase:
Use FlutterFlow's visual interface to build your UI.
Use custom actions or functions to interact with the Firebase SDK, which will automatically handle local caching and synchronization.
Example Code (Illustrative - adding a patient to Firestore with offline persistence):
import 'package:cloud_firestore/cloud_firestore.dart';
Future addPatient(String firstName, String lastName, String dob) async {
try {
await FirebaseFirestore.instance.collection('patients').add({
'first_name': firstName,
'last_name': lastName,
'dob': dob,
'timestamp': FieldValue.serverTimestamp(), // Important for conflict resolution
});
} catch (e) {
print("Error adding patient: $e");
}
}
Use code with caution.
Dart
Important Considerations:
Conflict Resolution: Carefully design your conflict resolution strategy. Common approaches include:
Last Write Wins: The last modification overwrites previous changes.
Server Wins: The data from the online database always takes precedence.
Client Wins: The local changes are always kept.
Custom Merge Logic: You write code to merge the changes based on specific rules. Using timestamps can help determine which data is newer.
Data Modeling: Design your data model to support synchronization efficiently. Consider adding fields like:
last_updated_at (timestamp): To track when data was last modified.
is_deleted (boolean): To handle deletions logically (soft deletes instead of hard deletes).
server_id (string): To store the ID of the corresponding record in the online database (if applicable).
Testing: Thoroughly test your synchronization logic to ensure data consistency and prevent data loss. Simulate offline and online scenarios, and test various conflict resolution cases.
Security: Secure both your local and online databases appropriately. Use encryption for sensitive data stored locally, and implement proper authentication and authorization for your online database.
By carefully considering your project's requirements, choosing the right approach, and implementing robust synchronization logic, you can successfully build applications that leverage the benefits of both local and online databases, providing a seamless and efficient user experience.

[@rehaanu]

@@MrIzeQ Thank you for detailed possibilities, however im a new developer and using supabase backend, i tried powersync but in long term its too costly. im looking for a basic solution like of firebase but my DB is not scalable on firebase. i have seen some tutorials of flutterflow for manual sync but its too complicated for me especially when my DB will be used by multi tenants. im creating a point of sale and business solutions software. flutterflow is what i need for scalability on different platforms.

[@MrIzeQ]

@@rehaanu nothing is complicated with the use of AI, go to google ai studio, pick gemini exp 1206, and let it be your personal PHD tutor

[@kavoshgar9733]

Majid is a nice tutor

[@RR-et6zp]

dude, people will use supabase, not sqllite