feat: support Spanner PostgreSQL databases

.github/workflows/integration-tests-on-emulator.yml

@@ -24,3 +24,13 @@ jobs:
         run: go test -v
         env:
           SPANNER_EMULATOR_HOST: localhost:9010
+      - name: Run PostgreSQL integration tests on Emulator
+        run: go test -v
+        working-directory: postgresql
+        env:
+          SPANNER_EMULATOR_HOST: localhost:9010
+      - name: Run PostgreSQL sample application integration tests on Emulator
+        run: go test -v
+        working-directory: postgresql/samples/sample_application
+        env:
+          SPANNER_EMULATOR_HOST: localhost:9010

.github/workflows/integration-tests-on-production.yml

@@ -33,7 +33,7 @@ jobs:
         with:
           credentials_json: ${{ secrets.GCP_SA_KEY }}
       - name: Run integration tests on production
-        run: go test -v -timeout 45m ./... -run '^TestIntegration_'
+        run: go test -v -timeout 45m -run '^TestIntegration_'
         env:
           JOB_TYPE: test
           SPANNER_TEST_PROJECT: ${{ secrets.GCP_PROJECT_ID }}
@@ -42,7 +42,7 @@ jobs:
         working-directory: ./samples/sample_application
         run: |
           go mod tidy
-          go test -v -timeout 45m ./... -run '^TestIntegration_'
+          go test -v -timeout 45m -run '^TestIntegration_'
         env:
           JOB_TYPE: test
           SPANNER_TEST_PROJECT: ${{ secrets.GCP_PROJECT_ID }}

.github/workflows/postgresql.yml

@@ -0,0 +1,32 @@
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+name: PostgreSQL-dialect tests
+jobs:
+  emulator-tests:
+    runs-on: ubuntu-latest
+    services:
+      emulator:
+        image: gcr.io/cloud-spanner-emulator/emulator:latest
+        ports:
+          - 9010:9010
+          - 9020:9020
+    steps:
+      - name: Install Go
+        uses: actions/setup-go@v6
+        with:
+          go-version: 1.25.x
+      - name: Checkout code
+        uses: actions/checkout@v6
+      - name: Checkout gorm
+        uses: actions/checkout@v6
+        with:
+          repository: go-gorm/gorm
+          path: postgresql/tests/gorm
+      - name: Run gorm PostgreSQL tests on Emulator
+        working-directory: postgresql/tests
+        run: ./run_gorm_tests.sh
+        env:
+          SPANNER_EMULATOR_HOST: localhost:9010

.github/workflows/samples-postgresql.yml

@@ -0,0 +1,35 @@
+on:
+  pull_request:
+    branches: [ main ]
+name: Run Samples for PostgreSQL
+jobs:
+  samples:
+    strategy:
+      matrix:
+        go-version: [1.24.x, 1.25.x]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Install Go
+        uses: actions/setup-go@v6
+        with:
+          go-version: ${{ matrix.go-version }}
+      - name: Checkout code
+        uses: actions/checkout@v6
+      - name: Run Hello World
+        working-directory: ./postgresql/samples/helloworld
+        run: go run main.go
+      - name: Run Quickstart
+        working-directory: ./postgresql/samples/quickstart
+        run: go run main.go
+      - name: Run sample application
+        working-directory: ./postgresql/samples
+        run: go run run_sample.go
+      - name: Run snippets
+        working-directory: ./postgresql/samples
+        run: |
+          for filename in snippets/*.go; do
+            name=${filename##*/}
+            base=${name%.go}
+            echo "Running sample $base"
+            go run run_sample.go "$base" || ! break
+          done

README.md

@@ -1,46 +1,83 @@
-# go-gorm-spanner
+# gorm Dialect for Spanner
 
 [![go.dev reference](https://img.shields.io/badge/go.dev-reference-007d9c?logo=go&logoColor=white&style=flat-square)](https://pkg.go.dev/github.com/googleapis/go-gorm-spanner)
 
-[Google Cloud Spanner](https://cloud.google.com/spanner) ORM for
-Go's [GORM](https://gorm.io/) implementation.
+[Google Cloud Spanner](https://cloud.google.com/spanner) ORM for Go's [GORM](https://gorm.io/) implementation.
+
+This project contains `gorm` dialects for both Spanner GoogleSQL and Spanner PostgreSQL databases.
+
+## GoogleSQL
+
+This example shows how to connect `gorm` to a Spanner GoogleSQL database.
 
 ``` go
 import (
-    "gorm.io/gorm"
-    _ "github.com/googleapis/go-sql-spanner"
+	"fmt"
 
-    spannergorm "github.com/googleapis/go-gorm-spanner"
+	spannergorm "github.com/googleapis/go-gorm-spanner"
+	_ "github.com/googleapis/go-sql-spanner"
+	"gorm.io/gorm"
 )
 
-db, err := gorm.Open(spannergorm.New(spannergorm.Config{
-    DriverName: "spanner",
-    DSN:        "projects/PROJECT/instances/INSTANCE/databases/DATABASE",
-}), &gorm.Config{PrepareStmt: true})
-if err != nil {
-    log.Fatal(err)
+func helloWorld(projectId, instanceId, databaseId string) error {
+	db, err := gorm.Open(spannergorm.New(spannergorm.Config{
+		DriverName: "spanner",
+		DSN:        fmt.Sprintf("projects/%s/instances/%s/databases/%s", projectId, instanceId, databaseId),
+	}), &gorm.Config{PrepareStmt: true})
+	if err != nil {
+		return fmt.Errorf("failed to open database connection: %v\n", err)
+	}
+	var msg string
+	if err := db.Raw("SELECT 'Hello World!'").Scan(&msg).Error; err != nil {
+		return fmt.Errorf("failed to execute query: %v", err)
+	}
+	fmt.Println(msg)
+
+	return nil
 }
+```
 
-// Print singers with more than 500 likes.
-type Singer struct {
-    gorm.Model
-    Text         string
-    Likes        int
-}
-var singers []Singer
-if err := db.Where("likes > ?", 500).Find(&singers).Error; err != nil {
-    log.Fatal(err)
-}
-for s := range singers {
-    fmt.Println(s.ID, s.Text)
+See the [samples directory](samples) for more examples.
+
+## PostgreSQL
+
+This example shows how to connect `gorm` to a Spanner PostgreSQL database.
+
+``` go
+import (
+	"fmt"
+
+	spannerpg "github.com/googleapis/go-gorm-spanner/postgresql"
+	_ "github.com/googleapis/go-sql-spanner"
+	"gorm.io/driver/postgres"
+	"gorm.io/gorm"
+)
+
+func helloWorld(projectId, instanceId, databaseId string) error {
+	db, err := gorm.Open(spannerpg.New(postgres.Config{
+		DSN: fmt.Sprintf("projects/%s/instances/%s/databases/%s", projectId, instanceId, databaseId),
+	}), &gorm.Config{})
+	if err != nil {
+		return fmt.Errorf("failed to open database connection: %v\n", err)
+	}
+	var msg string
+	if err := db.Raw("SELECT $1::varchar as greeting", "Hello World from Spanner PostgreSQL!").Scan(&msg).Error; err != nil {
+		return fmt.Errorf("failed to execute query: %v", err)
+	}
+	fmt.Println(msg)
+
+	return nil
 }
 ```
 
-### Connection URL Properties
+See the [PostgreSQL samples directory](postgresql/samples) for more examples for how to use this library with a Spanner
+PostgreSQL database.
+
+## Connection URL Properties
 
 The Cloud Spanner GORM supports the following connection URL properties
 
-#### Commonly Used Properties
+### Commonly Used Properties
 - credentials (String): File name for the credentials to use. The connection will use the default credentials of the environment if no credentials file is specified in the connection string. Example: `projects/my-project/instances/my-instance/databases/my-db;credentials=/path/to/credentials.json`
 - optimizerVersion (String): Sets the default query optimizer version to use for this connection. See also https://cloud.google.com/spanner/docs/query-optimizer/query-optimizer-versions.
 - isolationLevel (String): Sets the default isolation level for read/write transaction. The default is `sql.LevelSerializable`. Other supported values are `sql.LevelRepeatableRead`. Example: `fmt.Sprintf("projects/my-project/instances/my-instance/databases/my-db;isolationLevel=%s", sql.LevelRepeatableRead)`
@@ -51,15 +88,15 @@ minimum and maximum number of sessions for `gorm`.
 
 See https://cloud.google.com/spanner/docs/sessions#multiplexed_sessions for more information about multiplexed sessions.
 
-#### Advanced Properties
+### Advanced Properties
 - numChannels (int): Sets the number of gRPC channels to use. Defaults to 4.
 - retryAbortsInternally (boolean): Boolean that indicates whether the connection should automatically retry aborted errors. The default is true.
 - disableRouteToLeader (boolean): Boolean that indicates if all the requests of type read-write and PDML need to be routed to the leader region. The default is false.
 - usePlainText (boolean): : Boolean that indicates whether the connection should use plain text communication or not. Set this to true to connect to local mock servers that do not use SSL. Example: `projects/test-project/instances/test-instance/databases/test-db;usePlainText=true`
 
 Example: `projects/my-project/instances/my-instance/databases/my-db;numChannels=4;retryAbortsInternally=true;disableRouteToLeader=false;usePlainText=false`
 
-#### Additional Spanner Configuration
+### Additional Spanner Configuration
 You can also connect `gorm` to Spanner using a `driver.Connector`. This allows you to supply additional configuration
 for the Spanner client that should be used for `gorm`:
 

array_types_test.go

@@ -76,7 +76,8 @@ func TestInsertNativeArrays(t *testing.T) {
 	if g, w := len(req.Params.Fields), 9; g != w {
 		t.Errorf("num params mismatch\n Got: %v\nWant: %v", g, w)
 	}
-	if g, w := len(req.ParamTypes), 9; g != w {
+	// String arrays are sent as untyped values to allow Spanner to infer the data type from the SQL statement.
+	if g, w := len(req.ParamTypes), 8; g != w {
 		t.Errorf("num param types mismatch\n Got: %v\nWant: %v", g, w)
 	}
 	wantParamTypes := []spannerpb.TypeCode{
@@ -86,13 +87,19 @@ func TestInsertNativeArrays(t *testing.T) {
 		spannerpb.TypeCode_INT64,
 		spannerpb.TypeCode_FLOAT32,
 		spannerpb.TypeCode_FLOAT64,
-		spannerpb.TypeCode_STRING,
+		spannerpb.TypeCode_TYPE_CODE_UNSPECIFIED,
 		spannerpb.TypeCode_TIMESTAMP,
 	}
 	for i, code := range wantParamTypes {
 		param := fmt.Sprintf("p%d", i+1)
-		if g, w := req.ParamTypes[param].ArrayElementType.Code, code; g != w {
-			t.Errorf("%s: param type mismatch\n Got: %v\nWant: %v", param, g, w)
+		if tp, ok := req.ParamTypes[param]; ok {
+			if g, w := tp.ArrayElementType.Code, code; g != w {
+				t.Errorf("%s: param type mismatch\n Got: %v\nWant: %v", param, g, w)
+			}
+		} else {
+			if g, w := spannerpb.TypeCode_TYPE_CODE_UNSPECIFIED, code; g != w {
+				t.Errorf("%s: param type mismatch\n Got: %v\nWant: %v", param, g, w)
+			}
 		}
 	}
 	wantValues := []string{

benchmarks/go.mod

@@ -7,66 +7,65 @@ toolchain go1.25.5
 replace github.com/googleapis/go-gorm-spanner => ../
 
 require (
-	cloud.google.com/go/spanner v1.87.0
+	cloud.google.com/go/spanner v1.88.0
 	github.com/google/uuid v1.6.0
-	github.com/googleapis/go-gorm-spanner v1.9.0
-	github.com/googleapis/go-sql-spanner v1.22.0
-	google.golang.org/genproto v0.0.0-20251222181119-0a764e51fe1b
+	github.com/googleapis/go-gorm-spanner v1.9.1
+	github.com/googleapis/go-sql-spanner v1.23.0
+	google.golang.org/genproto v0.0.0-20260128011058-8636f8732409
 	google.golang.org/grpc v1.78.0
 	gorm.io/datatypes v1.2.7
 	gorm.io/gorm v1.31.1
 )
 
 require (
-	cel.dev/expr v0.24.0 // indirect
+	cel.dev/expr v0.25.1 // indirect
 	cloud.google.com/go v0.123.0 // indirect
-	cloud.google.com/go/auth v0.17.0 // indirect
+	cloud.google.com/go/auth v0.18.1 // indirect
 	cloud.google.com/go/auth/oauth2adapt v0.2.8 // indirect
 	cloud.google.com/go/compute/metadata v0.9.0 // indirect
 	cloud.google.com/go/iam v1.5.3 // indirect
-	cloud.google.com/go/longrunning v0.7.0 // indirect
+	cloud.google.com/go/longrunning v0.8.0 // indirect
 	cloud.google.com/go/monitoring v1.24.3 // indirect
 	filippo.io/edwards25519 v1.1.0 // indirect
-	github.com/GoogleCloudPlatform/grpc-gcp-go/grpcgcp v1.5.3 // indirect
+	github.com/GoogleCloudPlatform/grpc-gcp-go/grpcgcp v1.6.0 // indirect
 	github.com/GoogleCloudPlatform/opentelemetry-operations-go/detectors/gcp v1.30.0 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
-	github.com/cncf/xds/go v0.0.0-20251022180443-0feb69152e9f // indirect
-	github.com/envoyproxy/go-control-plane/envoy v1.35.0 // indirect
-	github.com/envoyproxy/protoc-gen-validate v1.2.1 // indirect
+	github.com/cncf/xds/go v0.0.0-20251210132809-ee656c7534f5 // indirect
+	github.com/envoyproxy/go-control-plane/envoy v1.36.0 // indirect
+	github.com/envoyproxy/protoc-gen-validate v1.3.0 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/go-jose/go-jose/v4 v4.1.3 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
-	github.com/go-sql-driver/mysql v1.8.1 // indirect
-	github.com/golang/groupcache v0.0.0-20241129210726-2c02b8208cf8 // indirect
+	github.com/go-sql-driver/mysql v1.9.3 // indirect
 	github.com/google/s2a-go v0.1.9 // indirect
-	github.com/googleapis/enterprise-certificate-proxy v0.3.7 // indirect
-	github.com/googleapis/gax-go/v2 v2.15.0 // indirect
+	github.com/googleapis/enterprise-certificate-proxy v0.3.11 // indirect
+	github.com/googleapis/gax-go/v2 v2.17.0 // indirect
 	github.com/hashicorp/golang-lru/v2 v2.0.7 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
 	github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10 // indirect
 	github.com/spiffe/go-spiffe/v2 v2.6.0 // indirect
 	go.opencensus.io v0.24.0 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
-	go.opentelemetry.io/contrib/detectors/gcp v1.38.0 // indirect
-	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.62.0 // indirect
-	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.62.0 // indirect
-	go.opentelemetry.io/otel v1.38.0 // indirect
-	go.opentelemetry.io/otel/metric v1.38.0 // indirect
-	go.opentelemetry.io/otel/sdk v1.38.0 // indirect
-	go.opentelemetry.io/otel/sdk/metric v1.38.0 // indirect
-	go.opentelemetry.io/otel/trace v1.38.0 // indirect
-	golang.org/x/crypto v0.45.0 // indirect
-	golang.org/x/net v0.47.0 // indirect
-	golang.org/x/oauth2 v0.33.0 // indirect
-	golang.org/x/sync v0.18.0 // indirect
-	golang.org/x/sys v0.38.0 // indirect
-	golang.org/x/text v0.31.0 // indirect
+	go.opentelemetry.io/contrib/detectors/gcp v1.39.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.64.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.64.0 // indirect
+	go.opentelemetry.io/otel v1.39.0 // indirect
+	go.opentelemetry.io/otel/metric v1.39.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.39.0 // indirect
+	go.opentelemetry.io/otel/sdk/metric v1.39.0 // indirect
+	go.opentelemetry.io/otel/trace v1.39.0 // indirect
+	golang.org/x/crypto v0.47.0 // indirect
+	golang.org/x/net v0.49.0 // indirect
+	golang.org/x/oauth2 v0.35.0 // indirect
+	golang.org/x/sync v0.19.0 // indirect
+	golang.org/x/sys v0.40.0 // indirect
+	golang.org/x/text v0.33.0 // indirect
 	golang.org/x/time v0.14.0 // indirect
-	google.golang.org/api v0.257.0 // indirect
-	google.golang.org/genproto/googleapis/api v0.0.0-20251213004720-97cd9d5aeac2 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 // indirect
+	google.golang.org/api v0.266.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20260203192932-546029d2fa20 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260203192932-546029d2fa20 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
-	gorm.io/driver/mysql v1.5.6 // indirect
+	gorm.io/driver/mysql v1.6.0 // indirect
 )