yml2ddl

name	yml2ddl
description	Generate SQL DDL statements from Starlake YAML definitions

YML to DDL Skill

Generates SQL DDL (Data Definition Language) statements: CREATE TABLE, ALTER TABLE, etc.: from your Starlake YAML table definitions. Supports multiple target databases through type mappings defined in types/default.sl.yml.

Usage

starlake yml2ddl [options]

Options

• --datawarehouse <value>: Target data warehouse name: must match a DDL mapping key in types/default.sl.yml (required). Examples: bigquery, snowflake, postgres, redshift, synapse, duckdb
• --connection <value>: JDBC connection name with read/write access (for --apply mode)
• --output <value>: Output directory for generated DDL files (default: ./{datawarehouse}/)
• --catalog <value>: Database catalog name (if applicable)
• --domain <value>: Generate DDL for this specific domain only (default: all domains)
• --schemas <value>: Comma-separated list of schemas within the domain to generate DDL for
• --apply: Execute the generated DDL directly against the database
• --parallelism <value>: Parallelism level (default: available CPU cores)
• --reportFormat <value>: Report output format: console, json, or html

Configuration Context

Type Mappings in types/default.sl.yml

The DDL generation uses ddlMapping to map Starlake types to database-specific types:

# metadata/types/default.sl.yml
types:
  - name: "string"
    primitiveType: "string"
    ddlMapping:
      bigquery: "STRING"
      snowflake: "VARCHAR"
      postgres: "TEXT"
      duckdb: "VARCHAR"
      synapse: "NVARCHAR(MAX)"

  - name: "long"
    primitiveType: "long"
    ddlMapping:
      bigquery: "INT64"
      snowflake: "BIGINT"
      postgres: "BIGINT"
      duckdb: "BIGINT"

  - name: "decimal"
    primitiveType: "decimal"
    ddlMapping:
      bigquery: "NUMERIC"
      snowflake: "NUMBER(38,9)"
      postgres: "NUMERIC"

Examples

Generate DDL for BigQuery

starlake yml2ddl --datawarehouse bigquery

Generate DDL for Snowflake (Specific Domain)

starlake yml2ddl --datawarehouse snowflake --domain starbake

Generate and Apply DDL to PostgreSQL

starlake yml2ddl --datawarehouse postgres --connection my_pg_conn --apply

Generate DDL to Custom Output Directory

starlake yml2ddl --datawarehouse duckdb --output /tmp/ddl

Generate DDL for Specific Schemas

starlake yml2ddl --datawarehouse snowflake --domain sales --schemas orders,customers

Parallel DDL Generation

starlake yml2ddl --datawarehouse bigquery --parallelism 4

Related Skills

• extract-script - Generate extraction scripts from templates
• xls2yml - Convert Excel to YAML (before DDL generation)
• config - Configuration reference (type mappings)