DataJoint 2.1

.gitignore

@@ -195,3 +195,8 @@ datajoint.json
 
 # Test outputs
 *_test_summary.txt
+
+# Swap files
+*.swp
+*.swo
+*~

docker-compose.yaml

@@ -24,6 +24,19 @@ services:
       timeout: 30s
       retries: 5
       interval: 15s
+  postgres:
+    image: postgres:${POSTGRES_VER:-15}
+    environment:
+      - POSTGRES_PASSWORD=${PG_PASS:-password}
+      - POSTGRES_USER=${PG_USER:-postgres}
+      - POSTGRES_DB=${PG_DB:-test}
+    ports:
+      - "5432:5432"
+    healthcheck:
+      test: [ "CMD-SHELL", "pg_isready -U postgres" ]
+      timeout: 30s
+      retries: 5
+      interval: 15s
   minio:
     image: minio/minio:${MINIO_VER:-RELEASE.2025-02-28T09-55-16Z}
     environment:
@@ -52,6 +65,8 @@ services:
     depends_on:
       db:
         condition: service_healthy
+      postgres:
+        condition: service_healthy
       minio:
         condition: service_healthy
     environment:
@@ -61,6 +76,10 @@ services:
       - DJ_TEST_HOST=db
       - DJ_TEST_USER=datajoint
       - DJ_TEST_PASSWORD=datajoint
+      - DJ_PG_HOST=postgres
+      - DJ_PG_USER=postgres
+      - DJ_PG_PASS=password
+      - DJ_PG_PORT=5432
       - S3_ENDPOINT=minio:9000
       - S3_ACCESS_KEY=datajoint
       - S3_SECRET_KEY=datajoint

pyproject.toml

@@ -89,7 +89,7 @@ test = [
   "pytest-cov",
   "requests",
   "graphviz",
-  "testcontainers[mysql,minio]>=4.0",
+  "testcontainers[mysql,minio,postgres]>=4.0",
   "polars>=0.20.0",
   "pyarrow>=14.0.0",
 ]
@@ -98,14 +98,16 @@ test = [
 s3 = ["s3fs>=2023.1.0"]
 gcs = ["gcsfs>=2023.1.0"]
 azure = ["adlfs>=2023.1.0"]
+postgres = ["psycopg2-binary>=2.9.0"]
 polars = ["polars>=0.20.0"]
 arrow = ["pyarrow>=14.0.0"]
 test = [
   "pytest",
   "pytest-cov",
   "requests",
   "s3fs>=2023.1.0",
-  "testcontainers[mysql,minio]>=4.0",
+  "testcontainers[mysql,minio,postgres]>=4.0",
+  "psycopg2-binary>=2.9.0",
   "polars>=0.20.0",
   "pyarrow>=14.0.0",
 ]
@@ -227,6 +229,9 @@ ignore-words-list = "rever,numer,astroid"
 markers = [
     "requires_mysql: marks tests as requiring MySQL database (deselect with '-m \"not requires_mysql\"')",
     "requires_minio: marks tests as requiring MinIO object storage (deselect with '-m \"not requires_minio\"')",
+    "mysql: marks tests that run on MySQL backend (select with '-m mysql')",
+    "postgresql: marks tests that run on PostgreSQL backend (select with '-m postgresql')",
+    "backend_agnostic: marks tests that should pass on all backends (auto-marked for parameterized tests)",
 ]
 
 

src/datajoint/adapters/__init__.py

@@ -0,0 +1,54 @@
+"""
+Database adapter registry for DataJoint.
+
+This module provides the adapter factory function and exports all adapters.
+"""
+
+from __future__ import annotations
+
+from .base import DatabaseAdapter
+from .mysql import MySQLAdapter
+from .postgres import PostgreSQLAdapter
+
+__all__ = ["DatabaseAdapter", "MySQLAdapter", "PostgreSQLAdapter", "get_adapter"]
+
+# Adapter registry mapping backend names to adapter classes
+ADAPTERS: dict[str, type[DatabaseAdapter]] = {
+    "mysql": MySQLAdapter,
+    "postgresql": PostgreSQLAdapter,
+    "postgres": PostgreSQLAdapter,  # Alias for postgresql
+}
+
+
+def get_adapter(backend: str) -> DatabaseAdapter:
+    """
+    Get adapter instance for the specified database backend.
+
+    Parameters
+    ----------
+    backend : str
+        Backend name: 'mysql', 'postgresql', or 'postgres'.
+
+    Returns
+    -------
+    DatabaseAdapter
+        Adapter instance for the specified backend.
+
+    Raises
+    ------
+    ValueError
+        If the backend is not supported.
+
+    Examples
+    --------
+    >>> from datajoint.adapters import get_adapter
+    >>> mysql_adapter = get_adapter('mysql')
+    >>> postgres_adapter = get_adapter('postgresql')
+    """
+    backend_lower = backend.lower()
+
+    if backend_lower not in ADAPTERS:
+        supported = sorted(set(ADAPTERS.keys()))
+        raise ValueError(f"Unknown database backend: {backend}. " f"Supported backends: {', '.join(supported)}")
+
+    return ADAPTERS[backend_lower]()