generate

Generate test data from a schema file.

seedling generate

The main command. Generates test data from a schema file and writes it to the specified output.

Usage

seedling generate [options]

Flags

Flag	Description	Default
--count	Rows per root table	100
--seed	Deterministic seed (0 = random)	0
--schema	Schema file path	schema.yaml
--output	Output file or directory	stdout
--format	Output format (sql, csv, jsonl, parquet)	sql
--batch-size	Rows per batch	1000
--db	Direct database insert DSN	—
--copy	Use COPY protocol (Postgres only)	false
--truncate	TRUNCATE tables before inserting	false
--generators	YAML generator overrides file	—
--config	seedling.yaml config file	—
--dry-run	Print plan without generating	false
--parallel	Generate tables in parallel	false
--verbose	Progress bars and summary	false

Examples

Basic SQL Generation

seedling generate --count 10000 --output seed.sql

Deterministic Generation

seedling generate --count 50000 --seed 42 --output seed.sql

Direct Database Insert

seedling generate --count 500000 --db postgres://localhost:5432/staging

Postgres COPY Protocol (Max Throughput)

seedling generate --count 1000000 --db postgres://localhost:5432/staging --copy

CSV Output

seedling generate --count 10000 --output data/ --format csv

Dry Run

seedling generate --count 500000 --dry-run --verbose

Output:

Plan:
  users:    500,000 rows
  orders:   1,200,000 rows (FK: users.id)
  payments: 1,200,000 rows (FK: orders.id)
  ---
  Total:    2,900,000 rows
  Est. size: 450 MB
  FK order: users → orders → payments

With Generator Overrides

seedling generate --count 10000 --generators overrides.yaml

With Config File

seedling generate --config seedling.yaml