Db Migration Helper

DB Migration Helper

分析 model 变更，生成安全的数据库迁移 SQL。

Overview

对比代码中的实体/模型定义与当前数据库 schema，检测结构变更（新增表、增删列、改类型），生成向前兼容的迁移 SQL。支持 MySQL、PostgreSQL、SQLite。

When to Use

• User wants to create database migrations
• User modified model/entity definitions
• User mentions migration, schema change, or sync
• User says "生成迁移" / "create migration"
• User inputs /db-migration-helper

When NOT to Use:

• User only wants to view database structure
• User wants data migration (not schema)
• User uses ORM auto-migration
• User wants to generate seed data
• User wants to backup/restore database

Core Pattern

Step 1: 检测项目类型和 ORM

Step 2: 提取当前 Schema

# Prisma (v5+)
npx prisma db pull 2>/dev/null

# Prisma (v4 及更早)
npx prisma introspect 2>/dev/null

# 通用 — 从代码提取
grep -r "CREATE TABLE\|@Entity\|@Table\|model " --include="*.ts" --include="*.py" --include="*.go" -l

提取：

• 表名和列定义
• 列类型、约束（NOT NULL、DEFAULT、UNIQUE）
• 索引和外键

Step 3: 对比变更

对比代码中的 model 定义与已有 schema（或上一次迁移），检测：

Step 4: 生成迁移文件

使用 templates/migration.sql 模板，生成：

1. Up 迁移 — 正向变更 SQL 2. Down 回滚 — 反向回滚 SQL 3. 风险评估 — 标注高风险操作

-- Migration: 20260603_add_user_avatar
-- Risk: LOW

-- Up
ALTER TABLE users ADD COLUMN avatar_url VARCHAR(500);
CREATE INDEX idx_users_email ON users(email);

-- Down
DROP INDEX idx_users_email;
ALTER TABLE users DROP COLUMN avatar_url;

Quick Reference

/db-migration-helper                    # 检测变更，生成迁移
/db-migration-helper --dry-run          # 只预览 SQL 不执行
/db-migration-helper --name add_user    # 指定迁移名称

Common Mistakes

DB Migration Helper

Analyze model changes and generate safe database migration SQL.

Installation

# npx skills (recommended)
npx skills add wu529778790/shenzjd-skills -s db-migration-helper -y

# Manual (Claude Code)
git clone https://github.com/wu529778790/shenzjd-skills.git
cp -r shenzjd-skills/db-migration-helper ~/.claude/skills/

# Manual (Cursor)
# Copy SKILL.md content to .cursorrules or .cursor/rules/

Usage

/db-migration-helper                    # Detect changes, generate migration
/db-migration-helper --dry-run          # Preview SQL only
/db-migration-helper --name add_user    # Specify migration name

Supported Databases

Output

Each migration includes:

• Up SQL — Forward changes
• Down SQL — Rollback statements
• Risk Assessment — Flags high-risk operations (drop column, type change)