sql-orm
What is sql-orm?
sql-orm is a code-first ORM for Rust applications that use Microsoft SQL Server.
It lets you define your database model using Rust structs, derive metadata from those structs, build typed queries, generate SQL Server-specific SQL, run migrations, and execute everything through Tiberius.
Rust structs
↓
Entity metadata
↓
Query AST
↓
SQL Server SQL
↓
Tiberius
↓
Entity / DTO
The goal is to keep application code strongly typed, expressive, and close to your domain while still producing real parameterized SQL Server SQL.
Table of Contents
- Highlights
- When Should You Use It?
- Installation
- Published Crates
- Quick Example
- Query Builder
- DTO Projections
- Aggregations
- Relationships
- Entity Policies
- Raw SQL
- Migrations
- Architecture
- Current Limits
- Documentation
- Local Validation
Highlights
| Feature | Description |
|---|---|
| Code-first models | Rust structs define database metadata, schema snapshots, and migrations |
| SQL Server-first | Designed specifically for SQL Server syntax, parameters, DDL, and rowversion |
| Typed queries | Build filters, ordering, pagination, joins, includes, projections, and aggregations safely |
| Derive-based API | Use Entity, Insertable, Changeset, DbContext, and FromRow |
| Safe raw SQL | Execute manual SQL using parameters and typed result mapping |
| Migrations | Generate reviewable SQL from Rust metadata snapshots |
| Entity policies | Declare audit, soft delete, and tenant behavior from model metadata |
| Layered design | Clear separation between metadata, AST, SQL generation, execution, and migrations |
When Should You Use It?
Use sql-orm if you want:
- A Rust-first development experience for SQL Server.
- Code-first schema metadata.
- Typed query construction instead of scattered SQL strings.
- SQL Server-specific behavior instead of a generic multi-database abstraction.
- A clean public API over Tiberius.
- Reviewable migrations generated from model snapshots.
[!NOTE] SQL Server is currently the only supported backend.
[!WARNING] This project is currently prepared as the
0.2.0-rc.1pre-release. The release candidate has full workspace validation for the documented surface, but keeps explicit limits listed in Current Limits.
Installation
Use the public root crate from crates.io:
[]
= "0.2.0-rc.1"
With optional bb8 pooling support:
[]
= { = "0.2.0-rc.1", = ["pool-bb8"] }
Import the prelude:
use *;
Install the migration CLI from crates.io when you need migration commands:
The prelude exposes the normal user-facing API:
- Public derives
DbContextDbSet- Query extensions
- Error types
- Metadata contracts
- Common SQL values
- Mapping traits
Published Crates
All workspace crates are published on crates.io. Application code should normally depend only on sql-orm; the other crates are documented for advanced use and architecture visibility.
| Crate | crates.io | API docs | Purpose |
|---|---|---|---|
sql-orm |
package | docs | Public facade for applications |
sql-orm-cli |
package | docs | Migration and database commands |
sql-orm-core |
package | docs | Contracts, metadata, SQL values, errors, and neutral rows |
sql-orm-macros |
package | docs | Derives and metadata generation |
sql-orm-query |
package | docs | Query AST and query-builder primitives |
sql-orm-sqlserver |
package | docs | SQL Server query and DDL compilation |
sql-orm-tiberius |
package | docs | Connections, execution, transactions, rows, and pooling |
sql-orm-migrate |
package | docs | Snapshots, diffs, operations, and migration helpers |
Quick Example
1. Define an entity
use *;
2. Define write models
3. Define a context
4. Insert, find, update, and delete
let db = connect.await?;
let saved = db
.users
.insert
.await?;
let found = db.users.find.await?;
let updated = db
.users
.update
.await?;
let deleted = db.users.delete.await?;
The ORM reads the generated entity metadata, builds the SQL Server statement, binds parameters safely, executes it through Tiberius, and materializes the result back into your Rust type.
Query Builder
Generated columns are typed query symbols.
let active_users = db
.users
.query
.filter
.order_by
.take
.all
.await?;
The query builder produces a neutral AST. SQL Server SQL is generated only by sql-orm-sqlserver.
flowchart LR
A[Typed Rust Query] --> B[Query AST]
B --> C[SQL Server Compiler]
C --> D[Parameterized SQL]
D --> E[Tiberius Execution]
E --> F[Entity / DTO]
DTO Projections
Use DTO projections when you do not need full entities.
use *;
let summaries = db
.users
.query
.select
.
.await?;
DTO projections can use:
- Entity columns
- Aliased expressions
- Explicit joins
- Selected subsets of columns
- Custom
FromRowmappings
Aggregations
Scalar aggregate methods are available from DbSetQuery:
let count = db.orders.query.count.await?;
let has_paid_orders = db
.orders
.query
.filter
.exists
.await?;
let total_cents = db
.orders
.query
.filter
.
.await?;
Grouped aggregates use DTO materialization through FromRow:
let totals = db
.orders
.query
.group_by?
.try_select_aggregate?
.
.await?;
Aggregations preserve explicit joins and root tenant / soft_delete filters.
They do not infer hidden navigation joins; add explicit joins or navigation
join helpers before calling aggregate methods.
Relationships
Relationships are explicit and metadata-driven.
use *;
Include a related entity:
let posts = db
.posts
.query
.?
.all
.await?;
let author = posts.user.as_ref;
Include a collection:
let users = db
.users
.query
.?
.max_joined_rows
.all
.await?;
let posts = users.posts.as_slice;
[!IMPORTANT] Navigation fields do not trigger hidden database I/O when accessed. Lazy wrappers represent loaded or not-loaded state, but they do not store context or execute SQL by themselves.
Entity Policies
Entity policies let you declare cross-cutting behavior from metadata.
flowchart TD
A[Entity Metadata] --> B[Audit Policy]
A --> C[Soft Delete Policy]
A --> D[Tenant Policy]
B --> E[Runtime Inserts / Updates]
C --> F[Query Filters / Delete Behavior]
D --> G[Fail-Closed Tenant Scope]
Auditing
use ;
use *;
Audit columns are part of schema metadata. They do not need to appear as fields on the entity itself.
Soft Delete
#[orm(soft_delete = SoftDelete)] converts public delete operations into logical-delete updates.
Normal queries hide deleted rows by default.
Tenant Scoping
#[orm(tenant = CurrentTenant)] enables fail-closed tenant filters for opt-in entities.
Reads and writes on the root entity apply tenant scoping automatically.
[!CAUTION] Raw SQL and manual joins require explicit tenant and visibility predicates.
Raw SQL
Use raw SQL when the query builder does not model the statement you need yet.
let rows = db
.
.param
.all
.await?;
Execute a command:
let result = db
.raw_exec
.params
.execute
.await?;
| API | Purpose |
|---|---|
raw<T>() |
Query rows and map them into a typed result |
raw_exec() |
Execute commands such as UPDATE, DELETE, or custom SQL |
.param(...) |
Bind a single parameter |
.params(...) |
Bind multiple parameters |
Migrations
The migration flow is based on snapshots and reviewable SQL.
sequenceDiagram
participant Dev as Developer
participant Model as Rust Entities
participant Snapshot as Model Snapshot
participant Diff as Migration Diff
participant SQL as up.sql / down.sql
participant DB as SQL Server
Dev->>Model: Change entities
Model->>Snapshot: Export metadata snapshot
Snapshot->>Diff: Compare previous/current model
Diff->>SQL: Generate migration SQL
Dev->>SQL: Review migration files
SQL->>DB: Apply database update
Create a migration:
Apply pending migrations:
Generate a downgrade script to keep a known target migration applied:
Execute that same rollback flow directly:
Use --target 0 only when you explicitly want to roll back all local
migrations. Downgrade requires local up.sql for checksum validation and an
executable down.sql for every migration being rolled back; it does not infer
reverse SQL from snapshots.
Generated artifacts:
| File | Purpose |
|---|---|
up.sql |
SQL applied when migrating forward |
down.sql |
SQL used by database downgrade for reviewed or executed rollback |
model_snapshot.json |
Captured model metadata after the migration |
[!NOTE]
migration.rsis not part of the current MVP.
Transactions and Pooling
db.transaction(...) is available on contexts created from a direct connection.
With the optional pool-bb8 feature, db.transaction(...) is also supported
for contexts created from from_pool(...). The runtime checks out one physical
pooled SQL Server connection, pins it for the full closure, runs BEGIN,
COMMIT or ROLLBACK on that same connection, and then returns it to the
pool. Runtime tenant, audit, soft-delete and tracking state stay on the shared
context handle, and save_changes() reuses the active transaction instead of
opening a nested one.
The Tiberius layer exposes configuration for:
- Timeouts
- Retry
- Tracing
- Slow-query logging
- Health checks
- Optional pooling
Architecture
The workspace is split by responsibility.
| Crate | Responsibility |
|---|---|
sql-orm-core |
Contracts, metadata, SQL values, errors, and neutral rows |
sql-orm-macros |
Derives and metadata generation |
sql-orm-query |
Query AST and query-builder primitives |
sql-orm-sqlserver |
SQL Server query and DDL compilation |
sql-orm-tiberius |
Connections, execution, transactions, rows, and pooling |
sql-orm-migrate |
Snapshots, diffs, operations, and migration helpers |
sql-orm-cli |
Migration and database commands |
sql-orm |
Public facade for applications |
flowchart TB
A[sql-orm] --> B[sql-orm-core]
A --> C[sql-orm-macros]
A --> D[sql-orm-query]
D --> E[sql-orm-sqlserver]
E --> F[sql-orm-tiberius]
B --> G[sql-orm-migrate]
G --> H[sql-orm-cli]
This separation keeps each layer focused:
core -> contracts and metadata
query -> AST only
sqlserver -> SQL generation
tiberius -> execution
migrate -> schema evolution
sql-orm -> public API
Current Limits
See docs/stability-audit.md for the updated stability boundaries.
| Area | Current status |
|---|---|
| Backend support | SQL Server only |
Tracked<T> |
Stable for explicit single-primary-key tracking |
save_changes() |
Stable for explicit single-primary-key tracking |
| Composite primary keys | Metadata exists, public persistence support is limited |
| Tracking ownership | Pending Added, Modified, and Deleted work is registry-owned after wrapper drop/consume; detached loaded identities can reattach to registry snapshots; one live tracked handle per persisted identity is allowed per context |
| Relationship graph persistence | Not implemented; persist dependents or explicit join entities directly |
| Many-to-many navigation | Use an explicit join entity |
| Lazy loading | No automatic I/O from field access |
include_many(...).split_query() |
API exists, execution returns not implemented |
| Aggregations | Scalar and grouped APIs exist; window functions, rollups, cubes, distinct aggregates and automatic policy filters over manually joined entities are deferred |
| Raw SQL filters | Tenant and soft-delete filters must be written manually |
database downgrade |
Available through explicit --target; requires local checksums and executable down.sql |
migration.rs |
Deferred |
| Pooled transactions | Supported with pool-bb8; one physical connection is pinned for the closure |
Documentation
| Resource | Description |
|---|---|
| Published API docs | Rustdoc for the root public crate |
| crates.io package | Published package metadata and install snippet |
| CLI package | Installable migration and database command-line tool |
| Core concepts | Repository guide for the mental model and end-to-end flow |
| Quickstart | Repository guide for connection, CRUD, and query builder |
| Code-first guide | Repository guide for entities, derives, DbContext, and metadata |
| Public API | Repository guide for the public surface exported from the root crate |
| Query builder | Repository guide for filters, ordering, pagination, joins, includes, projections, and aggregations |
| Navigation properties | Repository guide for belongs_to, has_one, has_many, includes, and limits |
| Typed projections | Repository guide for select(...), all_as::<T>(), aliases, and DTOs |
| Typed aggregations | Repository guide for count, exists, scalar aggregates, group_by, HAVING, and DTOs |
| Typed raw SQL | Repository guide for raw<T>(), raw_exec(), parameters, and security |
| Relationships | Repository guide for foreign keys, joins, navigation, and loading |
| Transactions | Repository guide for runtime behavior and pooled transactions |
| Migrations | Repository guide for snapshots, diffs, migration add, database update, and database downgrade |
| Entity policies | Repository guide for audit, soft delete, tenant, and limits |
| Tracking stability | Repository guide for stabilization criteria for tracking APIs |
| Use from another project | Repository guide for using the published crates |
Examples
[!NOTE] Last real SQL Server validation for the
todo-appsmoke flow was run on 2026-05-17 against localtempdbwithDATABASE_URL: fixture setup, ignored smoke test, HTTP read endpoints and migration script apply all passed. Rerun the integration tests and smoke flow before treating a future release candidate as freshly validated.
Local Validation
Run standard checks:
Tests against a real SQL Server instance require: