From abae73ef1e10aac5332895b1c13ed7fd61b54711 Mon Sep 17 00:00:00 2001
From: adlerhurst <27845747+adlerhurst@users.noreply.github.com>
Date: Fri, 13 Jun 2025 11:59:22 +0200
Subject: [PATCH] this is the proposal i mentioned in the review

---
 backend/v3/domain/instance.go                 |  2 +-
 backend/v3/storage/database/database.go       |  8 +++
 .../storage/database/dialect/postgres/rows.go | 49 ++++++++++++++++++-
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/backend/v3/domain/instance.go b/backend/v3/domain/instance.go
index 82e6ac451f..acbee10c1b 100644
--- a/backend/v3/domain/instance.go
+++ b/backend/v3/domain/instance.go
@@ -87,7 +87,7 @@ type InstanceRepository interface {
 	// Member() MemberRepository
 
 	Get(ctx context.Context, opts ...database.Condition) (*Instance, error)
-	List(ctx context.Context, opts ...database.Condition) ([]Instance, error)
+	List(ctx context.Context, opts ...database.Condition) ([]*Instance, error)
 
 	Create(ctx context.Context, instance *Instance) error
 	Update(ctx context.Context, condition database.Condition, changes ...database.Change) (int64, error)
diff --git a/backend/v3/storage/database/database.go b/backend/v3/storage/database/database.go
index f94037eaa5..a04aff4993 100644
--- a/backend/v3/storage/database/database.go
+++ b/backend/v3/storage/database/database.go
@@ -61,3 +61,11 @@ type Row interface {
 type Rows interface {
 	pgx.Rows
 }
+
+// Collector is an interface for collecting rows into a specific type.
+type Collector[T any] interface {
+	// Collect collects a single row into the specified type.
+	Collect(Row) (T, error)
+	// CollectRows collects multiple rows into a slice of the specified type.
+	CollectRows(Rows) ([]T, error)
+}
diff --git a/backend/v3/storage/database/dialect/postgres/rows.go b/backend/v3/storage/database/dialect/postgres/rows.go
index 7a36979a5e..8dafc88f4f 100644
--- a/backend/v3/storage/database/dialect/postgres/rows.go
+++ b/backend/v3/storage/database/dialect/postgres/rows.go
@@ -1,11 +1,58 @@
 package postgres
 
 import (
+	"github.com/georgysavva/scany/v2/pgxscan"
 	"github.com/jackc/pgx/v5"
 
 	"github.com/zitadel/zitadel/backend/v3/storage/database"
 )
 
-var _ database.Rows = (*Rows)(nil)
+var (
+	_ database.Rows            = (*Rows)(nil)
+	_ database.CollectableRows = (*Rows)(nil)
+)
 
 type Rows struct{ pgx.Rows }
+
+// Collect implements [database.CollectableRows].
+// See [this page](https://github.com/georgysavva/scany/blob/master/dbscan/doc.go#L8) for additional details.
+func (r *Rows) Collect(dest any) (err error) {
+	defer func() {
+		closeErr := r.Close()
+		if err == nil {
+			err = closeErr
+		}
+	}()
+	return pgxscan.ScanAll(dest, r.Rows)
+}
+
+// CollectFirst implements [database.CollectableRows].
+// See [this page](https://github.com/georgysavva/scany/blob/master/dbscan/doc.go#L8) for additional details.
+func (r *Rows) CollectFirst(dest any) (err error) {
+	defer func() {
+		closeErr := r.Close()
+		if err == nil {
+			err = closeErr
+		}
+	}()
+	return pgxscan.ScanRow(dest, r.Rows)
+}
+
+// CollectExactlyOneRow implements [database.CollectableRows].
+// See [this page](https://github.com/georgysavva/scany/blob/master/dbscan/doc.go#L8) for additional details.
+func (r *Rows) CollectExactlyOneRow(dest any) (err error) {
+	defer func() {
+		closeErr := r.Close()
+		if err == nil {
+			err = closeErr
+		}
+	}()
+	return pgxscan.ScanOne(dest, r.Rows)
+}
+
+// Close implements [database.Rows].
+// Subtle: this method shadows the method (Rows).Close of Rows.Rows.
+func (r *Rows) Close() error {
+	r.Rows.Close()
+	return nil
+}