What is data-migration-scripts?

A guide to writing database migration scripts, which safely change table structures or transform existing data. It includes checks, rollback steps, and ways to make changes with little or no downtime.

Use it to add or change columns, move data between systems, clean up or reshape records, split or merge tables, and backfill new fields.

It reduces the risk of losing or corrupting data when changing a live database. Reversible steps and validation make schema changes and large data updates easier to recover from.

data-migration-scripts — Skill for Claude Code and Codex by aj-geddes

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add aj-geddes/useful-ai-prompts --skill data-migration-scripts

Clone the repo

git clone --depth 1 https://github.com/aj-geddes/useful-ai-prompts

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/aj-geddes/useful-ai-prompts/data-migration-scripts/github.svg)](https://agentmods.dev/skills/aj-geddes/useful-ai-prompts/data-migration-scripts)

Your own site

<a href="https://agentmods.dev/skills/aj-geddes/useful-ai-prompts/data-migration-scripts"><img src="https://agentmods.dev/badge/skills/aj-geddes/useful-ai-prompts/data-migration-scripts/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/aj-geddes/useful-ai-prompts/data-migration-scripts"><img src="https://agentmods.dev/badge/skills/aj-geddes/useful-ai-prompts/data-migration-scripts.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 781 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits

Socket pass 18 Mar 2026
Snyk pass 4 Mar 2026

How audits are shown

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00045	$0.00781
Opus 5.5	$0.00018	$0.00312
Sonnet 5.5	$0.00009	$0.00156
Haiku 4.5	$0.00005	$0.00078

Measured 2mo ago against content hash 6ee2bf4efb24, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

data-migration-scripts scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/validate-schema.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/data-migration-scripts/SKILL.md · 110 lines

How it starts

The opening of the file, as written. The whole thing — 110 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Overview

Create robust, safe, and reversible data migration scripts for database schema changes and data transformations with minimal downtime.

When to Use

Database schema changes
Adding/removing/modifying columns
Migrating between database systems
Data transformations and cleanup
Splitting or merging tables
Changing data types
Adding indexes and constraints
Backfilling data
Multi-tenant data migrations

Quick Start

Minimal working example:

import { Knex } from "knex";

// migrations/20240101000000_add_user_preferences.ts
export async function up(knex: Knex): Promise<void> {
  // Create new table
  await knex.schema.createTable("user_preferences", (table) => {
    table.uuid("id").primary().defaultTo(knex.raw("gen_random_uuid()"));
    table
      .uuid("user_id")
      .notNullable()
      .references("id")
      .inTable("users")
      .onDelete("CASCADE");
    table.jsonb("preferences").defaultTo("{}");
    table.timestamp("created_at").defaultTo(knex.fn.now());
    table.timestamp("updated_at").defaultTo(knex.fn.now());

    table.index("user_id");
  });

  // Migrate existing data
  await knex.raw(`
    INSERT INTO user_preferences (user_id, preferences)
    SELECT id, jsonb_build_object(
      'theme', COALESCE(theme, 'light'),
// ... (see reference guides for full implementation)

Reference Guides

Detailed implementations in the references/ directory:

Guide	Contents
Knex.js Migrations (Node.js)	Knex.js Migrations (Node.js)
Alembic Migrations (Python/SQLAlchemy)	Alembic Migrations (Python/SQLAlchemy)
Large Data Migration with Batching	Large Data Migration with Batching
Zero-Downtime Migration Pattern	Zero-Downtime Migration Pattern
Migration Validation	Migration Validation
Cross-Database Migration	Cross-Database Migration

Read the full file on GitHub · 110 lines

Files

What ships with it

8 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 110 lines · 45 tokens per session scan A 6ee2bf4efb24

Subscribe to this mod's changes

data-migration-scripts is a skill published in the GitHub repository aj-geddes/useful-ai-prompts (376 stars, last pushed 8mo ago), licensed MIT. It adds 45 tokens to every session and 781 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

Databases DevOps and cloud

data-migration-scripts next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
data-migration-scriptsaj-geddes/useful-ai-prompts	Skill	376	8mo ago	MIT	A	45	Claude Code, Codex
create-prprisma/orm	Skill	48k	yesterday	Apache-2.0	A	48	Claude Code, Codex
schema-explorationlangchain-ai/deepagents	Skill	31k	yesterday	MIT	A	57	Claude Code, Codex
atlas-mssqlariga/atlas	Skill	8.8k	yesterday	Apache-2.0	A	163	Claude Code
ha-data-storesshiwenwen/hope-agent	Skill	1.9k	yesterday	MIT	A	115	Claude Code, Codex
nornicdb-cypher-queriesorneryd/NornicDB	Skill	923	yesterday	MIT	A	79	Claude Code, Codex
volcengine-rds-postgresqlbytedance/agentkit-samples	Skill	484	today	Apache-2.0	A	63	Claude Code, Codex

data-migration-scripts