# Drizzle adapter

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|  | This documentation is for<br>an as-yet unreleased<br>version of Cerbos PDP. Choose 0.53.0 from the version picker at the top right or navigate to [https://docs.cerbos.dev](https://docs.cerbos.dev/) for the latest version. |

The `@cerbos/orm-drizzle` package converts a Cerbos [`PlanResources`](https://docs.cerbos.dev/cerbos/prerelease/api/#resources-query-plan) response into a Drizzle ORM SQL expression. The resulting filter can be composed with your existing query builder chain.

## Requirements

- Cerbos >= v0.16
- `@cerbos/http` or `@cerbos/grpc` client
- Drizzle ORM (SQLite, PostgreSQL, MySQL, PlanetScale)
- Node.js >= 20.0.0

## Installation

```bash
npm install @cerbos/orm-drizzle
```

## Supported operators

- Logical: `and`, `or`, `not`
- Comparison: `eq`, `ne`, `lt`, `gt`, `le`, `ge`, `in`
- String: `contains`, `startsWith`, `endsWith`
- Existence: `isSet`
- Collection: `hasIntersection`, `exists`, `exists_one`, `all`, `filter`
- Relation-aware mappings with `EXISTS` subqueries

## Usage

```typescript
import { queryPlanToDrizzle, PlanKind } from "@cerbos/orm-drizzle";
import { eq, and } from "drizzle-orm";
import { resources } from "./schema";

const plan = await cerbos.planResources({
  principal,
  resource: { kind: "document" },
  action: "view",
});

const result = queryPlanToDrizzle({
  queryPlan: plan,
  mapper: {
    "request.resource.attr.status": resources.status,
    "request.resource.attr.owner": resources.ownerId,
  },
});

switch (result.kind) {
  case PlanKind.ALWAYS_DENIED:
    return [];
  case PlanKind.ALWAYS_ALLOWED:
    return await db.select().from(resources);
  case PlanKind.CONDITIONAL:
    return await db
      .select()
      .from(resources)
      .where(result.filter);
}
```

## Field mapper

The mapper associates Cerbos attribute references with Drizzle columns. It accepts:
- A plain object with keys as Cerbos attribute references and values as Drizzle columns or SQL expressions
- A function receiving the attribute reference and returning the column or expression
- An object with a `column` property and an optional `transform` function for custom SQL translation

```typescript
const result = queryPlanToDrizzle({
  queryPlan,
  mapper: {
    "request.resource.attr.custom": {
      column: sql`lower(${resources.title})`,
      transform: ({ operator, value }) => {
        if (operator !== "eq") throw new Error("Unsupported");
        return eq(sql`lower(${resources.title})`, value.toLowerCase());
      },
    },
  },
});
```

## Relation mapping

The adapter wraps relation comparisons in `EXISTS` subqueries, automatically inferring relation fields when they match column names on the related table.

```typescript
const result = queryPlanToDrizzle({
  queryPlan,
  mapper: {
    "request.resource.attr.owner": {
      relation: {
        type: "one",
        table: owners,
        sourceColumn: resources.ownerId,
        targetColumn: owners.id,
        fields: {
          email: owners.email,
        },
      },
    },
    "request.resource.attr.tags": {
      relation: {
        type: "many",
        table: resourceTags,
        sourceColumn: resources.id,
        targetColumn: resourceTags.resourceId,
        fields: {
          name: {
            relation: {
              type: "one",
              table: tags,
              sourceColumn: resourceTags.tagId,
              targetColumn: tags.id,
              field: tags.name,
            },
          },
        },
      },
    },
  },
});
```

## Collection operators

- `hasIntersection` — translates to `column IN (…​)` for multi-valued attributes mapped as nested relations
- `exists`, `exists_one`, `all` — generate correlated `EXISTS` subqueries with the lambda variable scoped to the relation
- `filter` — Cerbos uses this during plan construction; the adapter discards the lambda since the filter is applied in Drizzle

## Source code

[cerbos/query-plan-adapters/drizzle](https://github.com/cerbos/query-plan-adapters/tree/main/drizzle)