fix: support zeroValue tag on DeletedAt (#6011)

* fix: support zeroValue tag on DeletedAt

Signed-off-by: qiankunli <qiankun.li@qq.com>

* Update soft_delete_test.go

* Update tests_test.go

* Update soft_delete.go

---------

Signed-off-by: qiankunli <qiankun.li@qq.com>
Co-authored-by: Jinzhu <wosmvp@gmail.com>

soft_delete.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"reflect"
 
+	"github.com/jinzhu/now"
 	"gorm.io/gorm/clause"
 	"gorm.io/gorm/schema"
 )
@@ -45,11 +46,21 @@ func (n *DeletedAt) UnmarshalJSON(b []byte) error {
 }
 
 func (DeletedAt) QueryClauses(f *schema.Field) []clause.Interface {
-	return []clause.Interface{SoftDeleteQueryClause{Field: f}}
+	return []clause.Interface{SoftDeleteQueryClause{Field: f, ZeroValue: parseZeroValueTag(f)}}
+}
+
+func parseZeroValueTag(f *schema.Field) sql.NullString {
+	if v, ok := f.TagSettings["ZEROVALUE"]; ok {
+		if _, err := now.Parse(v); err == nil {
+			return sql.NullString{String: v, Valid: true}
+		}
+	}
+	return sql.NullString{Valid: false}
 }
 
 type SoftDeleteQueryClause struct {
-	Field *schema.Field
+	ZeroValue sql.NullString
+	Field     *schema.Field
 }
 
 func (sd SoftDeleteQueryClause) Name() string {
@@ -78,18 +89,19 @@ func (sd SoftDeleteQueryClause) ModifyStatement(stmt *Statement) {
 		}
 
 		stmt.AddClause(clause.Where{Exprs: []clause.Expression{
-			clause.Eq{Column: clause.Column{Table: clause.CurrentTable, Name: sd.Field.DBName}, Value: nil},
+			clause.Eq{Column: clause.Column{Table: clause.CurrentTable, Name: sd.Field.DBName}, Value: sd.ZeroValue},
 		}})
 		stmt.Clauses["soft_delete_enabled"] = clause.Clause{}
 	}
 }
 
 func (DeletedAt) UpdateClauses(f *schema.Field) []clause.Interface {
-	return []clause.Interface{SoftDeleteUpdateClause{Field: f}}
+	return []clause.Interface{SoftDeleteUpdateClause{Field: f, ZeroValue: parseZeroValueTag(f)}}
 }
 
 type SoftDeleteUpdateClause struct {
-	Field *schema.Field
+	ZeroValue sql.NullString
+	Field     *schema.Field
 }
 
 func (sd SoftDeleteUpdateClause) Name() string {
@@ -109,11 +121,12 @@ func (sd SoftDeleteUpdateClause) ModifyStatement(stmt *Statement) {
 }
 
 func (DeletedAt) DeleteClauses(f *schema.Field) []clause.Interface {
-	return []clause.Interface{SoftDeleteDeleteClause{Field: f}}
+	return []clause.Interface{SoftDeleteDeleteClause{Field: f, ZeroValue: parseZeroValueTag(f)}}
 }
 
 type SoftDeleteDeleteClause struct {
-	Field *schema.Field
+	ZeroValue sql.NullString
+	Field     *schema.Field
 }
 
 func (sd SoftDeleteDeleteClause) Name() string {

tests/soft_delete_test.go

@@ -7,6 +7,7 @@ import (
 	"regexp"
 	"testing"
 
+	"github.com/jinzhu/now"
 	"gorm.io/gorm"
 	. "gorm.io/gorm/utils/tests"
 )
@@ -98,3 +99,71 @@ func TestDeletedAtOneOr(t *testing.T) {
 		t.Fatalf("invalid sql generated, got %v", actualSQL)
 	}
 }
+
+func TestSoftDeleteZeroValue(t *testing.T) {
+	type SoftDeleteBook struct {
+		ID        uint
+		Name      string
+		Pages     uint
+		DeletedAt gorm.DeletedAt `gorm:"zeroValue:'1970-01-01 00:00:01'"`
+	}
+	DB.Migrator().DropTable(&SoftDeleteBook{})
+	if err := DB.AutoMigrate(&SoftDeleteBook{}); err != nil {
+		t.Fatalf("failed to auto migrate soft delete table")
+	}
+
+	book := SoftDeleteBook{Name: "jinzhu", Pages: 10}
+	DB.Save(&book)
+
+	var count int64
+	if DB.Model(&SoftDeleteBook{}).Where("name = ?", book.Name).Count(&count).Error != nil || count != 1 {
+		t.Errorf("Count soft deleted record, expects: %v, got: %v", 1, count)
+	}
+
+	var pages uint
+	if DB.Model(&SoftDeleteBook{}).Select("pages").Where("name = ?", book.Name).Scan(&pages).Error != nil || pages != book.Pages {
+		t.Errorf("Pages soft deleted record, expects: %v, got: %v", 0, pages)
+	}
+
+	if err := DB.Delete(&book).Error; err != nil {
+		t.Fatalf("No error should happen when soft delete user, but got %v", err)
+	}
+
+	zeroTime, _ := now.Parse("1970-01-01 00:00:01")
+	if book.DeletedAt.Time.Equal(zeroTime) {
+		t.Errorf("book's deleted at should not be zero, DeletedAt: %v", book.DeletedAt)
+	}
+
+	if DB.First(&SoftDeleteBook{}, "name = ?", book.Name).Error == nil {
+		t.Errorf("Can't find a soft deleted record")
+	}
+
+	count = 0
+	if DB.Model(&SoftDeleteBook{}).Where("name = ?", book.Name).Count(&count).Error != nil || count != 0 {
+		t.Errorf("Count soft deleted record, expects: %v, got: %v", 0, count)
+	}
+
+	pages = 0
+	if err := DB.Model(&SoftDeleteBook{}).Select("pages").Where("name = ?", book.Name).Scan(&pages).Error; err != nil || pages != 0 {
+		t.Fatalf("Age soft deleted record, expects: %v, got: %v, err %v", 0, pages, err)
+	}
+
+	if err := DB.Unscoped().First(&SoftDeleteBook{}, "name = ?", book.Name).Error; err != nil {
+		t.Errorf("Should find soft deleted record with Unscoped, but got err %s", err)
+	}
+
+	count = 0
+	if DB.Unscoped().Model(&SoftDeleteBook{}).Where("name = ?", book.Name).Count(&count).Error != nil || count != 1 {
+		t.Errorf("Count soft deleted record, expects: %v, count: %v", 1, count)
+	}
+
+	pages = 0
+	if DB.Unscoped().Model(&SoftDeleteBook{}).Select("pages").Where("name = ?", book.Name).Scan(&pages).Error != nil || pages != book.Pages {
+		t.Errorf("Age soft deleted record, expects: %v, got: %v", 0, pages)
+	}
+
+	DB.Unscoped().Delete(&book)
+	if err := DB.Unscoped().First(&SoftDeleteBook{}, "name = ?", book.Name).Error; !errors.Is(err, gorm.ErrRecordNotFound) {
+		t.Errorf("Can't find permanently deleted record")
+	}
+}