pgschema works with a full schema. Either the ORM itself or a custom program is needed to generate that full schema. Benefits over ORM’s built-in migrations:
  1. Concurrent change detection: Prevents conflicts when multiple developers modify the database
  2. Online DDL: Safe migrations with minimal downtime
Drizzle supports exporting the full schema with drizzle-kit export: 
# Edit your Drizzle schema file (e.g., schema.ts)
# Make desired changes to tables, columns, indexes, etc.

# Export Drizzle schema to SQL
drizzle-kit export > desired-schema.sql

# Plan migration
pgschema plan \
  --host localhost \
  --db mydb \
  --user postgres \
  --schema public \
  --file desired-schema.sql

# Apply migration
pgschema apply \
  --host localhost \
  --db mydb \
  --user postgres \
  --schema public \
  --file desired-schema.sql
If the ORM doesn’t support exporting full schema, you need to write a small program. Here’s an example for TypeORM: 
// export-full-schema.ts
import { DataSource } from "typeorm";
import { entities } from "./entities";

async function exportFullSchema() {
  const tempDataSource = new DataSource({
    type: "postgres",
    host: "localhost",
    database: "temp_db", // Use a temporary empty database
    synchronize: false,
    logging: false,
    entities: entities,
  });

  await tempDataSource.initialize();
  
  // This will generate full schema against empty db
  const sqlInMemory = await tempDataSource.driver
    .createSchemaBuilder()
    .log();
  
  sqlInMemory.upQueries.forEach(query => {
    console.log(query.query + ";");
  });
  
  await tempDataSource.destroy();
}

// Run the export
exportFullSchema();

# Edit your TypeORM schema file (e.g., src/entities/xxx.ts)
# Make desired changes to tables, columns, indexes, etc.

# Run the export script
npx ts-node export-full-schema.ts > desired-schema.sql

# Plan migration
pgschema plan \
  --host localhost \
  --db mydb \
  --user postgres \
  --schema public \
  --file desired-schema.sql

# Apply migration
pgschema apply \
  --host localhost \
  --db mydb \
  --user postgres \
  --schema public \
  --file desired-schema.sql