Feature: Error translator for Dialector

Author: re-cheid

go.mod

@@ -5,6 +5,7 @@ go 1.18
 require (
 	github.com/glebarez/go-sqlite v1.21.1
 	gorm.io/gorm v1.25.0
+	modernc.org/sqlite v1.21.1
 )
 
 require (
@@ -18,5 +19,4 @@ require (
 	modernc.org/libc v1.22.3 // indirect
 	modernc.org/mathutil v1.5.0 // indirect
 	modernc.org/memory v1.5.0 // indirect
-	modernc.org/sqlite v1.21.1 // indirect
 )

sqlite.go

@@ -8,7 +8,8 @@ import (
 
 	"gorm.io/gorm/callbacks"
 
-	_ "github.com/glebarez/go-sqlite"
+	gosqlite "github.com/glebarez/go-sqlite"
+	sqlite3 "modernc.org/sqlite/lib"
 
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"
@@ -197,6 +198,19 @@ func (dialectopr Dialector) RollbackTo(tx *gorm.DB, name string) error {
 	return nil
 }
 
+func (dialector Dialector) Translate(err error) error {
+	switch terr := err.(type) {
+	case *gosqlite.Error:
+		switch terr.Code() {
+		case sqlite3.SQLITE_CONSTRAINT_UNIQUE:
+			return gorm.ErrDuplicatedKey
+		case sqlite3.SQLITE_CONSTRAINT_PRIMARYKEY:
+			return gorm.ErrDuplicatedKey
+		}
+	}
+	return err
+}
+
 func compareVersion(version1, version2 string) int {
 	n, m := len(version1), len(version2)
 	i, j := 0, 0

sqlite_error_translator_test.go

@@ -0,0 +1,48 @@
+package sqlite
+
+import (
+	"testing"
+
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+)
+
+func TestErrorTranslator(t *testing.T) {
+	// This is the DSN of the in-memory SQLite database for these tests.
+	const InMemoryDSN = "file:testdatabase?mode=memory&cache=shared"
+
+	// This is the example object for testing the unique constraint error
+	type Article struct {
+		ArticleNumber string `gorm:"unique"`
+	}
+
+	db, err := gorm.Open(&Dialector{DSN: InMemoryDSN}, &gorm.Config{
+		Logger:         logger.Default.LogMode(logger.Silent),
+		TranslateError: true})
+
+	if err != nil {
+		t.Errorf("Expected Open to succeed; got error: %v", err)
+	}
+	if db == nil {
+		t.Errorf("Expected db to be non-nil.")
+	}
+
+	err = db.AutoMigrate(&Article{})
+	if err != nil {
+		t.Errorf("Expected to migrate database models to succeed: %v", err)
+	}
+
+	err = db.Create(&Article{ArticleNumber: "A00000XX"}).Error
+	if err != nil {
+		t.Errorf("Expected first create to succeed: %v", err)
+	}
+
+	err = db.Create(&Article{ArticleNumber: "A00000XX"}).Error
+	if err == nil {
+		t.Errorf("Expected second create to fail.")
+	}
+
+	if err != gorm.ErrDuplicatedKey {
+		t.Errorf("Expected error from second create to be gorm.ErrDuplicatedKey: %v", err)
+	}
+}