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D1 Drizzle Schema Skill for Claude

Generate Drizzle ORM schemas for Cloudflare D1 databases with correct D1-specific patterns. Produces schema files, migration commands, type exports, and DATABASE_SCHEMA.md documentation. Handles D1 quirks: foreign keys always enforced, no native BOOLEAN/DATETIME types, 100 bound parameter limit, JSON stored as TEXT. Use when creating a new database, adding tables, or scaffolding a D1 data layer.

5k tokens
context cost
the whole folder, loaded on every use
5
files
ships runnable scripts
0
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how many repositories repackaged it
953
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/jezweb/claude-skills --skill d1-drizzle-schema

The instruction itself

14 sections, as written by the author

D1 Drizzle Schema

Generate correct Drizzle ORM schemas for Cloudflare D1. D1 is SQLite-based but has important differences that cause subtle bugs if you use standard SQLite patterns. This skill produces schemas that work correctly with D1's constraints.

Critical D1 Differences

| Feature | Standard SQLite | D1 |

|---------|-----------------|-----|

| Foreign keys | OFF by default | Always ON (cannot disable) |

| Boolean type | No | No — use integer({ mode: 'boolean' }) |

| Datetime type | No | No — use integer({ mode: 'timestamp' }) |

| Max bound params | ~999 | 100 (affects bulk inserts) |

| JSON support | Extension | Always available (json_extract, ->, ->>) |

| Concurrency | Multi-writer | Single-threaded (one query at a time) |

Workflow

Step 1: Describe the Data Model

Gather requirements: what tables, what relationships, what needs indexing. If working from an existing description, infer the schema directly.

Step 2: Generate Drizzle Schema

Create schema files using D1-correct column patterns:

import { sqliteTable, text, integer, real, index, uniqueIndex } from 'drizzle-orm/sqlite-core'

export const users = sqliteTable('users', {
  // UUID primary key (preferred for D1)
  id: text('id').primaryKey().$defaultFn(() => crypto.randomUUID()),

  // Text fields
  name: text('name').notNull(),
  email: text('email').notNull(),

  // Enum (stored as TEXT, validated at schema level)
  role: text('role', { enum: ['admin', 'editor', 'viewer'] }).notNull().default('viewer'),

  // Boolean (D1 has no BOOL — stored as INTEGER 0/1)
  emailVerified: integer('email_verified', { mode: 'boolean' }).notNull().default(false),

  // Timestamp (D1 has no DATETIME — stored as unix seconds)
  createdAt: integer('created_at', { mode: 'timestamp' }).notNull().$defaultFn(() => new Date()),
  updatedAt: integer('updated_at', { mode: 'timestamp' }).notNull().$defaultFn(() => new Date()),

  // Typed JSON (stored as TEXT, Drizzle auto-serialises)
  preferences: text('preferences', { mode: 'json' }).$type<UserPreferences>(),

  // Foreign key (always enforced in D1)
  organisationId: text('organisation_id').references(() => organisations.id, { onDelete: 'cascade' }),
}, (table) => ({
  emailIdx: uniqueIndex('users_email_idx').on(table.email),
  orgIdx: index('users_org_idx').on(table.organisationId),
}))

See references/column-patterns.md for the full type reference.

Step 3: Add Relations

Drizzle relations are query builder helpers (separate from FK constraints):

import { relations } from 'drizzle-orm'

export const usersRelations = relations(users, ({ one, many }) => ({
  organisation: one(organisations, {
    fields: [users.organisationId],
    references: [organisations.id],
  }),
  posts: many(posts),
}))

Step 4: Export Types

export type User = typeof users.$inferSelect
export type NewUser = typeof users.$inferInsert

Step 5: Set Up Drizzle Config

Copy assets/drizzle-config-template.ts to drizzle.config.ts and update the schema path.

Step 6: Add Migration Scripts

Add to package.json:

{
  "db:generate": "drizzle-kit generate",
  "db:migrate:local": "wrangler d1 migrations apply DB --local",
  "db:migrate:remote": "wrangler d1 migrations apply DB --remote"
}

Always run on BOTH local AND remote before testing.

Step 7: Generate DATABASE_SCHEMA.md

Document the schema for future sessions:

  • Tables with columns, types, and constraints
  • Relationships and foreign keys
  • Indexes and their purpose
  • Migration workflow

Bulk Insert Pattern

D1 limits bound parameters to 100. Calculate batch size:

const BATCH_SIZE = Math.floor(100 / COLUMNS_PER_ROW)
for (let i = 0; i < rows.length; i += BATCH_SIZE) {
  await db.insert(table).values(rows.slice(i, i + BATCH_SIZE))
}

D1 Runtime Usage

import { drizzle } from 'drizzle-orm/d1'
import * as schema from './schema'

// In Worker fetch handler:
const db = drizzle(env.DB, { schema })

// Query patterns
const all = await db.select().from(schema.users).all()           // Array<User>
const one = await db.select().from(schema.users).where(eq(schema.users.id, id)).get()  // User | undefined
const count = await db.select({ count: sql`count(*)` }).from(schema.users).get()

Reference Files

| When | Read |

|------|------|

| D1 vs SQLite, JSON queries, limits | references/d1-specifics.md |

| Column type patterns for Drizzle + D1 | references/column-patterns.md |

Assets

| File | Purpose |

|------|---------|

| assets/drizzle-config-template.ts | Starter drizzle.config.ts for D1 |

| assets/schema-template.ts | Example schema with all common D1 patterns |

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How to use it

Copy the folder

Take jezweb/d1-drizzle-schema from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.