Function init_mongodb_to_postgres 

pub async fn init_mongodb_to_postgres(
    mongo_url: &str,
    target_url: &str,
) -> Result<()>

Initial replication from MongoDB to PostgreSQL

Performs one-time migration of MongoDB database to PostgreSQL target using JSONB storage:

1. Validates MongoDB connection string
2. Connects to MongoDB and verifies connection
3. Extracts database name from connection string
4. Lists all collections from MongoDB database
5. For each collection:
   • Converts documents to JSONB format
   • Creates JSONB table in PostgreSQL
   • Batch inserts all data

All MongoDB data is stored as JSONB with metadata:

• id: Original _id field (ObjectId → hex, String/Int → string)
• data: Complete document as JSON object
• _source_type: “mongodb”
• _migrated_at: Timestamp of migration

Arguments

• mongo_url - MongoDB connection string (mongodb:// or mongodb+srv://)
• target_url - PostgreSQL connection string for target (Seren) database

Returns

Returns Ok(()) if migration completes successfully.

Errors

This function will return an error if:

• MongoDB connection string is invalid
• Cannot connect to MongoDB database
• Database name is not specified in connection string
• Cannot connect to target PostgreSQL database
• Collection conversion fails
• Database creation or insert operations fail

Examples

init_mongodb_to_postgres(
    "mongodb://localhost:27017/mydb",
    "postgresql://user:pass@seren.example.com/targetdb"
).await?;