refactor(go): simplify identity table keys

go/vehicle-gateway/internal/identity/resolver.go

@@ -71,17 +71,14 @@ func identityBindingTableSQL(table string) string {
 		table = "vehicle_identity_binding"
 	}
 	return `CREATE TABLE IF NOT EXISTS ` + table + ` (
-  id BIGINT PRIMARY KEY AUTO_INCREMENT,
-  vin VARCHAR(32) NOT NULL,
+  vin VARCHAR(32) PRIMARY KEY,
   plate VARCHAR(32) NULL,
   phone VARCHAR(32) NULL,
   device_id VARCHAR(64) NULL,
-  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
   updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   UNIQUE KEY uk_identity_plate (plate),
   UNIQUE KEY uk_identity_phone (phone),
-  UNIQUE KEY uk_identity_device (device_id),
-  KEY idx_identity_vin (vin)
+  UNIQUE KEY uk_identity_device (device_id)
 )`
 }
 
@@ -103,7 +100,6 @@ const jt808RegistrationTableSQL = `CREATE TABLE IF NOT EXISTS jt808_registration
   latest_registered_at DATETIME NULL,
   latest_authenticated_at DATETIME NULL,
   latest_seen_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
-  created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
   updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   KEY idx_jt808_registration_device (device_id),
   KEY idx_jt808_registration_plate (plate),

go/vehicle-gateway/internal/identity/resolver_test.go

@@ -3,6 +3,7 @@ package identity
 import (
 	"context"
 	"database/sql"
+	"strings"
 	"testing"
 
 	"github.com/DATA-DOG/go-sqlmock"
@@ -202,6 +203,24 @@ func TestMySQLResolverEnsuresMinimalIdentitySchema(t *testing.T) {
 	}
 }
 
+func TestIdentitySchemaUsesBusinessKeysOnly(t *testing.T) {
+	binding := identityBindingTableSQL("vehicle_identity_binding")
+	registration := jt808RegistrationTableSQL
+	for _, sqlText := range []string{binding, registration} {
+		for _, column := range []string{"id BIGINT", "AUTO_INCREMENT", "created_at"} {
+			if strings.Contains(sqlText, column) {
+				t.Fatalf("identity schema should not contain %s:\n%s", column, sqlText)
+			}
+		}
+	}
+	if !strings.Contains(binding, "vin VARCHAR(32) PRIMARY KEY") {
+		t.Fatalf("binding table should key by vin:\n%s", binding)
+	}
+	if !strings.Contains(registration, "phone VARCHAR(32) PRIMARY KEY") {
+		t.Fatalf("registration table should key by phone:\n%s", registration)
+	}
+}
+
 func newMockDB(t *testing.T) (*sql.DB, sqlmock.Sqlmock) {
 	t.Helper()
 	db, mock, err := sqlmock.New()