How to Generate PostgreSQL Seed Data: Complete Guide
Step-by-step guide to generating realistic PostgreSQL seed data for testing, development, and demos. Includes JSONB, UUID, arrays, and foreign key support.
Why Generate PostgreSQL Seed Data?
PostgreSQL seed data is essential for:
- •Testing: Test your application with realistic data scenarios
- •Development: Work with data that matches production patterns
- •Demos: Show your application with populated, realistic data
- •Performance Testing: Test queries and pagination with large datasets
PostgreSQL-Specific Features
Supported PostgreSQL Types
Basic Types
- • INTEGER, BIGINT, SMALLINT
- • SERIAL, BIGSERIAL
- • VARCHAR, TEXT, CHAR
- • BOOLEAN
- • DATE, TIMESTAMP, TIMESTAMPTZ
Advanced Types
- • UUID (v4 generation)
- • JSONB (nested objects)
- • Arrays (integer[], text[])
- • DECIMAL, NUMERIC
- • ENUM types
Best Practices for PostgreSQL Seed Data
1. Use Realistic Data Types
Match your seed data types to production patterns. Use email types for email columns, names for name columns, and addresses for location data. MockBlast automatically infers appropriate data types from column names.
2. Maintain Referential Integrity
Always include foreign key relationships in your schema. MockBlast generates parent tables first, then child tables with valid foreign key references. This ensures your seed data maintains database constraints.
3. Test with Various Data Sizes
Generate different amounts of data for different testing scenarios. Small datasets (100-1000 rows) for unit tests, medium datasets (10,000-100,000 rows) for integration tests, and large datasets (1M+ rows) for performance testing.
Importing Seed Data into PostgreSQL
Once you've generated your seed data with MockBlast:
- 1.Download the SQL INSERT statements file from MockBlast
- 2.Connect to your PostgreSQL database using psql or your preferred client
- 3.Run the SQL file:
psql -d your_database -f seed_data.sql - 4.Verify the data was inserted correctly with a SELECT query
Related Resources
PostgreSQL Mock Data Generator
Generate production-ready PostgreSQL mock data with full support for JSONB, UUID, arrays, and Postgres-specific data types.
Foreign Keys & Referential Integrity
Learn how to generate PostgreSQL seed data with foreign key relationships and maintain referential integrity across tables.
JSONB Generator for PostgreSQL
Generate valid JSONB data for PostgreSQL with nested objects, arrays, and complex JSON structures for your seed data.
Test Data with Foreign Keys
Complete guide to creating test data with foreign key relationships for PostgreSQL and other SQL databases.
Frequently Asked Questions
- Does MockBlast support PostgreSQL JSONB columns?
- Yes! MockBlast has native JSONB support. You can define nested JSON structures and MockBlast will generate valid JSONB data that PostgreSQL accepts. Perfect for testing modern Postgres schemas with JSON columns.
- Can I generate UUID primary keys for PostgreSQL?
- Absolutely! MockBlast supports UUID generation for Postgres primary keys and foreign keys. It generates valid UUID v4 values and maintains referential integrity across tables automatically.
- How do I handle foreign keys in PostgreSQL seed data?
- MockBlast automatically handles foreign key relationships. When you import a schema with FOREIGN KEY constraints, MockBlast generates data that maintains referential integrity. Parent tables are populated first, then child tables reference valid parent IDs.
- Can I generate PostgreSQL array columns?
- Yes! MockBlast supports PostgreSQL array columns (e.g., integer[], text[], varchar[]). You can specify array types and MockBlast will generate properly formatted array data for Postgres.
- How large can my PostgreSQL seed data be?
- MockBlast can generate millions of rows of PostgreSQL data efficiently using server-side streaming. Perfect for seeding large databases or testing pagination and performance. Memory usage stays constant regardless of row count.