refactor: remove empty services (#116)

* remove empty services

* remove old factory

* remove old static files

* cleanup more duplicate service code

* file/folder reorg

backend/internal/data/ent/document_query.go

@@ -0,0 +1,765 @@
+// Code generated by ent, DO NOT EDIT.
+
+package ent
+
+import (
+	"context"
+	"database/sql/driver"
+	"fmt"
+	"math"
+
+	"entgo.io/ent/dialect/sql"
+	"entgo.io/ent/dialect/sql/sqlgraph"
+	"entgo.io/ent/schema/field"
+	"github.com/google/uuid"
+	"github.com/hay-kot/homebox/backend/internal/data/ent/attachment"
+	"github.com/hay-kot/homebox/backend/internal/data/ent/document"
+	"github.com/hay-kot/homebox/backend/internal/data/ent/documenttoken"
+	"github.com/hay-kot/homebox/backend/internal/data/ent/group"
+	"github.com/hay-kot/homebox/backend/internal/data/ent/predicate"
+)
+
+// DocumentQuery is the builder for querying Document entities.
+type DocumentQuery struct {
+	config
+	limit              *int
+	offset             *int
+	unique             *bool
+	order              []OrderFunc
+	fields             []string
+	predicates         []predicate.Document
+	withGroup          *GroupQuery
+	withDocumentTokens *DocumentTokenQuery
+	withAttachments    *AttachmentQuery
+	withFKs            bool
+	// intermediate query (i.e. traversal path).
+	sql  *sql.Selector
+	path func(context.Context) (*sql.Selector, error)
+}
+
+// Where adds a new predicate for the DocumentQuery builder.
+func (dq *DocumentQuery) Where(ps ...predicate.Document) *DocumentQuery {
+	dq.predicates = append(dq.predicates, ps...)
+	return dq
+}
+
+// Limit adds a limit step to the query.
+func (dq *DocumentQuery) Limit(limit int) *DocumentQuery {
+	dq.limit = &limit
+	return dq
+}
+
+// Offset adds an offset step to the query.
+func (dq *DocumentQuery) Offset(offset int) *DocumentQuery {
+	dq.offset = &offset
+	return dq
+}
+
+// Unique configures the query builder to filter duplicate records on query.
+// By default, unique is set to true, and can be disabled using this method.
+func (dq *DocumentQuery) Unique(unique bool) *DocumentQuery {
+	dq.unique = &unique
+	return dq
+}
+
+// Order adds an order step to the query.
+func (dq *DocumentQuery) Order(o ...OrderFunc) *DocumentQuery {
+	dq.order = append(dq.order, o...)
+	return dq
+}
+
+// QueryGroup chains the current query on the "group" edge.
+func (dq *DocumentQuery) QueryGroup() *GroupQuery {
+	query := &GroupQuery{config: dq.config}
+	query.path = func(ctx context.Context) (fromU *sql.Selector, err error) {
+		if err := dq.prepareQuery(ctx); err != nil {
+			return nil, err
+		}
+		selector := dq.sqlQuery(ctx)
+		if err := selector.Err(); err != nil {
+			return nil, err
+		}
+		step := sqlgraph.NewStep(
+			sqlgraph.From(document.Table, document.FieldID, selector),
+			sqlgraph.To(group.Table, group.FieldID),
+			sqlgraph.Edge(sqlgraph.M2O, true, document.GroupTable, document.GroupColumn),
+		)
+		fromU = sqlgraph.SetNeighbors(dq.driver.Dialect(), step)
+		return fromU, nil
+	}
+	return query
+}
+
+// QueryDocumentTokens chains the current query on the "document_tokens" edge.
+func (dq *DocumentQuery) QueryDocumentTokens() *DocumentTokenQuery {
+	query := &DocumentTokenQuery{config: dq.config}
+	query.path = func(ctx context.Context) (fromU *sql.Selector, err error) {
+		if err := dq.prepareQuery(ctx); err != nil {
+			return nil, err
+		}
+		selector := dq.sqlQuery(ctx)
+		if err := selector.Err(); err != nil {
+			return nil, err
+		}
+		step := sqlgraph.NewStep(
+			sqlgraph.From(document.Table, document.FieldID, selector),
+			sqlgraph.To(documenttoken.Table, documenttoken.FieldID),
+			sqlgraph.Edge(sqlgraph.O2M, false, document.DocumentTokensTable, document.DocumentTokensColumn),
+		)
+		fromU = sqlgraph.SetNeighbors(dq.driver.Dialect(), step)
+		return fromU, nil
+	}
+	return query
+}
+
+// QueryAttachments chains the current query on the "attachments" edge.
+func (dq *DocumentQuery) QueryAttachments() *AttachmentQuery {
+	query := &AttachmentQuery{config: dq.config}
+	query.path = func(ctx context.Context) (fromU *sql.Selector, err error) {
+		if err := dq.prepareQuery(ctx); err != nil {
+			return nil, err
+		}
+		selector := dq.sqlQuery(ctx)
+		if err := selector.Err(); err != nil {
+			return nil, err
+		}
+		step := sqlgraph.NewStep(
+			sqlgraph.From(document.Table, document.FieldID, selector),
+			sqlgraph.To(attachment.Table, attachment.FieldID),
+			sqlgraph.Edge(sqlgraph.O2M, false, document.AttachmentsTable, document.AttachmentsColumn),
+		)
+		fromU = sqlgraph.SetNeighbors(dq.driver.Dialect(), step)
+		return fromU, nil
+	}
+	return query
+}
+
+// First returns the first Document entity from the query.
+// Returns a *NotFoundError when no Document was found.
+func (dq *DocumentQuery) First(ctx context.Context) (*Document, error) {
+	nodes, err := dq.Limit(1).All(ctx)
+	if err != nil {
+		return nil, err
+	}
+	if len(nodes) == 0 {
+		return nil, &NotFoundError{document.Label}
+	}
+	return nodes[0], nil
+}
+
+// FirstX is like First, but panics if an error occurs.
+func (dq *DocumentQuery) FirstX(ctx context.Context) *Document {
+	node, err := dq.First(ctx)
+	if err != nil && !IsNotFound(err) {
+		panic(err)
+	}
+	return node
+}
+
+// FirstID returns the first Document ID from the query.
+// Returns a *NotFoundError when no Document ID was found.
+func (dq *DocumentQuery) FirstID(ctx context.Context) (id uuid.UUID, err error) {
+	var ids []uuid.UUID
+	if ids, err = dq.Limit(1).IDs(ctx); err != nil {
+		return
+	}
+	if len(ids) == 0 {
+		err = &NotFoundError{document.Label}
+		return
+	}
+	return ids[0], nil
+}
+
+// FirstIDX is like FirstID, but panics if an error occurs.
+func (dq *DocumentQuery) FirstIDX(ctx context.Context) uuid.UUID {
+	id, err := dq.FirstID(ctx)
+	if err != nil && !IsNotFound(err) {
+		panic(err)
+	}
+	return id
+}
+
+// Only returns a single Document entity found by the query, ensuring it only returns one.
+// Returns a *NotSingularError when more than one Document entity is found.
+// Returns a *NotFoundError when no Document entities are found.
+func (dq *DocumentQuery) Only(ctx context.Context) (*Document, error) {
+	nodes, err := dq.Limit(2).All(ctx)
+	if err != nil {
+		return nil, err
+	}
+	switch len(nodes) {
+	case 1:
+		return nodes[0], nil
+	case 0:
+		return nil, &NotFoundError{document.Label}
+	default:
+		return nil, &NotSingularError{document.Label}
+	}
+}
+
+// OnlyX is like Only, but panics if an error occurs.
+func (dq *DocumentQuery) OnlyX(ctx context.Context) *Document {
+	node, err := dq.Only(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return node
+}
+
+// OnlyID is like Only, but returns the only Document ID in the query.
+// Returns a *NotSingularError when more than one Document ID is found.
+// Returns a *NotFoundError when no entities are found.
+func (dq *DocumentQuery) OnlyID(ctx context.Context) (id uuid.UUID, err error) {
+	var ids []uuid.UUID
+	if ids, err = dq.Limit(2).IDs(ctx); err != nil {
+		return
+	}
+	switch len(ids) {
+	case 1:
+		id = ids[0]
+	case 0:
+		err = &NotFoundError{document.Label}
+	default:
+		err = &NotSingularError{document.Label}
+	}
+	return
+}
+
+// OnlyIDX is like OnlyID, but panics if an error occurs.
+func (dq *DocumentQuery) OnlyIDX(ctx context.Context) uuid.UUID {
+	id, err := dq.OnlyID(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return id
+}
+
+// All executes the query and returns a list of Documents.
+func (dq *DocumentQuery) All(ctx context.Context) ([]*Document, error) {
+	if err := dq.prepareQuery(ctx); err != nil {
+		return nil, err
+	}
+	return dq.sqlAll(ctx)
+}
+
+// AllX is like All, but panics if an error occurs.
+func (dq *DocumentQuery) AllX(ctx context.Context) []*Document {
+	nodes, err := dq.All(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return nodes
+}
+
+// IDs executes the query and returns a list of Document IDs.
+func (dq *DocumentQuery) IDs(ctx context.Context) ([]uuid.UUID, error) {
+	var ids []uuid.UUID
+	if err := dq.Select(document.FieldID).Scan(ctx, &ids); err != nil {
+		return nil, err
+	}
+	return ids, nil
+}
+
+// IDsX is like IDs, but panics if an error occurs.
+func (dq *DocumentQuery) IDsX(ctx context.Context) []uuid.UUID {
+	ids, err := dq.IDs(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return ids
+}
+
+// Count returns the count of the given query.
+func (dq *DocumentQuery) Count(ctx context.Context) (int, error) {
+	if err := dq.prepareQuery(ctx); err != nil {
+		return 0, err
+	}
+	return dq.sqlCount(ctx)
+}
+
+// CountX is like Count, but panics if an error occurs.
+func (dq *DocumentQuery) CountX(ctx context.Context) int {
+	count, err := dq.Count(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return count
+}
+
+// Exist returns true if the query has elements in the graph.
+func (dq *DocumentQuery) Exist(ctx context.Context) (bool, error) {
+	if err := dq.prepareQuery(ctx); err != nil {
+		return false, err
+	}
+	return dq.sqlExist(ctx)
+}
+
+// ExistX is like Exist, but panics if an error occurs.
+func (dq *DocumentQuery) ExistX(ctx context.Context) bool {
+	exist, err := dq.Exist(ctx)
+	if err != nil {
+		panic(err)
+	}
+	return exist
+}
+
+// Clone returns a duplicate of the DocumentQuery builder, including all associated steps. It can be
+// used to prepare common query builders and use them differently after the clone is made.
+func (dq *DocumentQuery) Clone() *DocumentQuery {
+	if dq == nil {
+		return nil
+	}
+	return &DocumentQuery{
+		config:             dq.config,
+		limit:              dq.limit,
+		offset:             dq.offset,
+		order:              append([]OrderFunc{}, dq.order...),
+		predicates:         append([]predicate.Document{}, dq.predicates...),
+		withGroup:          dq.withGroup.Clone(),
+		withDocumentTokens: dq.withDocumentTokens.Clone(),
+		withAttachments:    dq.withAttachments.Clone(),
+		// clone intermediate query.
+		sql:    dq.sql.Clone(),
+		path:   dq.path,
+		unique: dq.unique,
+	}
+}
+
+// WithGroup tells the query-builder to eager-load the nodes that are connected to
+// the "group" edge. The optional arguments are used to configure the query builder of the edge.
+func (dq *DocumentQuery) WithGroup(opts ...func(*GroupQuery)) *DocumentQuery {
+	query := &GroupQuery{config: dq.config}
+	for _, opt := range opts {
+		opt(query)
+	}
+	dq.withGroup = query
+	return dq
+}
+
+// WithDocumentTokens tells the query-builder to eager-load the nodes that are connected to
+// the "document_tokens" edge. The optional arguments are used to configure the query builder of the edge.
+func (dq *DocumentQuery) WithDocumentTokens(opts ...func(*DocumentTokenQuery)) *DocumentQuery {
+	query := &DocumentTokenQuery{config: dq.config}
+	for _, opt := range opts {
+		opt(query)
+	}
+	dq.withDocumentTokens = query
+	return dq
+}
+
+// WithAttachments tells the query-builder to eager-load the nodes that are connected to
+// the "attachments" edge. The optional arguments are used to configure the query builder of the edge.
+func (dq *DocumentQuery) WithAttachments(opts ...func(*AttachmentQuery)) *DocumentQuery {
+	query := &AttachmentQuery{config: dq.config}
+	for _, opt := range opts {
+		opt(query)
+	}
+	dq.withAttachments = query
+	return dq
+}
+
+// GroupBy is used to group vertices by one or more fields/columns.
+// It is often used with aggregate functions, like: count, max, mean, min, sum.
+//
+// Example:
+//
+//	var v []struct {
+//		CreatedAt time.Time `json:"created_at,omitempty"`
+//		Count int `json:"count,omitempty"`
+//	}
+//
+//	client.Document.Query().
+//		GroupBy(document.FieldCreatedAt).
+//		Aggregate(ent.Count()).
+//		Scan(ctx, &v)
+func (dq *DocumentQuery) GroupBy(field string, fields ...string) *DocumentGroupBy {
+	grbuild := &DocumentGroupBy{config: dq.config}
+	grbuild.fields = append([]string{field}, fields...)
+	grbuild.path = func(ctx context.Context) (prev *sql.Selector, err error) {
+		if err := dq.prepareQuery(ctx); err != nil {
+			return nil, err
+		}
+		return dq.sqlQuery(ctx), nil
+	}
+	grbuild.label = document.Label
+	grbuild.flds, grbuild.scan = &grbuild.fields, grbuild.Scan
+	return grbuild
+}
+
+// Select allows the selection one or more fields/columns for the given query,
+// instead of selecting all fields in the entity.
+//
+// Example:
+//
+//	var v []struct {
+//		CreatedAt time.Time `json:"created_at,omitempty"`
+//	}
+//
+//	client.Document.Query().
+//		Select(document.FieldCreatedAt).
+//		Scan(ctx, &v)
+func (dq *DocumentQuery) Select(fields ...string) *DocumentSelect {
+	dq.fields = append(dq.fields, fields...)
+	selbuild := &DocumentSelect{DocumentQuery: dq}
+	selbuild.label = document.Label
+	selbuild.flds, selbuild.scan = &dq.fields, selbuild.Scan
+	return selbuild
+}
+
+func (dq *DocumentQuery) prepareQuery(ctx context.Context) error {
+	for _, f := range dq.fields {
+		if !document.ValidColumn(f) {
+			return &ValidationError{Name: f, err: fmt.Errorf("ent: invalid field %q for query", f)}
+		}
+	}
+	if dq.path != nil {
+		prev, err := dq.path(ctx)
+		if err != nil {
+			return err
+		}
+		dq.sql = prev
+	}
+	return nil
+}
+
+func (dq *DocumentQuery) sqlAll(ctx context.Context, hooks ...queryHook) ([]*Document, error) {
+	var (
+		nodes       = []*Document{}
+		withFKs     = dq.withFKs
+		_spec       = dq.querySpec()
+		loadedTypes = [3]bool{
+			dq.withGroup != nil,
+			dq.withDocumentTokens != nil,
+			dq.withAttachments != nil,
+		}
+	)
+	if dq.withGroup != nil {
+		withFKs = true
+	}
+	if withFKs {
+		_spec.Node.Columns = append(_spec.Node.Columns, document.ForeignKeys...)
+	}
+	_spec.ScanValues = func(columns []string) ([]any, error) {
+		return (*Document).scanValues(nil, columns)
+	}
+	_spec.Assign = func(columns []string, values []any) error {
+		node := &Document{config: dq.config}
+		nodes = append(nodes, node)
+		node.Edges.loadedTypes = loadedTypes
+		return node.assignValues(columns, values)
+	}
+	for i := range hooks {
+		hooks[i](ctx, _spec)
+	}
+	if err := sqlgraph.QueryNodes(ctx, dq.driver, _spec); err != nil {
+		return nil, err
+	}
+	if len(nodes) == 0 {
+		return nodes, nil
+	}
+	if query := dq.withGroup; query != nil {
+		if err := dq.loadGroup(ctx, query, nodes, nil,
+			func(n *Document, e *Group) { n.Edges.Group = e }); err != nil {
+			return nil, err
+		}
+	}
+	if query := dq.withDocumentTokens; query != nil {
+		if err := dq.loadDocumentTokens(ctx, query, nodes,
+			func(n *Document) { n.Edges.DocumentTokens = []*DocumentToken{} },
+			func(n *Document, e *DocumentToken) { n.Edges.DocumentTokens = append(n.Edges.DocumentTokens, e) }); err != nil {
+			return nil, err
+		}
+	}
+	if query := dq.withAttachments; query != nil {
+		if err := dq.loadAttachments(ctx, query, nodes,
+			func(n *Document) { n.Edges.Attachments = []*Attachment{} },
+			func(n *Document, e *Attachment) { n.Edges.Attachments = append(n.Edges.Attachments, e) }); err != nil {
+			return nil, err
+		}
+	}
+	return nodes, nil
+}
+
+func (dq *DocumentQuery) loadGroup(ctx context.Context, query *GroupQuery, nodes []*Document, init func(*Document), assign func(*Document, *Group)) error {
+	ids := make([]uuid.UUID, 0, len(nodes))
+	nodeids := make(map[uuid.UUID][]*Document)
+	for i := range nodes {
+		if nodes[i].group_documents == nil {
+			continue
+		}
+		fk := *nodes[i].group_documents
+		if _, ok := nodeids[fk]; !ok {
+			ids = append(ids, fk)
+		}
+		nodeids[fk] = append(nodeids[fk], nodes[i])
+	}
+	query.Where(group.IDIn(ids...))
+	neighbors, err := query.All(ctx)
+	if err != nil {
+		return err
+	}
+	for _, n := range neighbors {
+		nodes, ok := nodeids[n.ID]
+		if !ok {
+			return fmt.Errorf(`unexpected foreign-key "group_documents" returned %v`, n.ID)
+		}
+		for i := range nodes {
+			assign(nodes[i], n)
+		}
+	}
+	return nil
+}
+func (dq *DocumentQuery) loadDocumentTokens(ctx context.Context, query *DocumentTokenQuery, nodes []*Document, init func(*Document), assign func(*Document, *DocumentToken)) error {
+	fks := make([]driver.Value, 0, len(nodes))
+	nodeids := make(map[uuid.UUID]*Document)
+	for i := range nodes {
+		fks = append(fks, nodes[i].ID)
+		nodeids[nodes[i].ID] = nodes[i]
+		if init != nil {
+			init(nodes[i])
+		}
+	}
+	query.withFKs = true
+	query.Where(predicate.DocumentToken(func(s *sql.Selector) {
+		s.Where(sql.InValues(document.DocumentTokensColumn, fks...))
+	}))
+	neighbors, err := query.All(ctx)
+	if err != nil {
+		return err
+	}
+	for _, n := range neighbors {
+		fk := n.document_document_tokens
+		if fk == nil {
+			return fmt.Errorf(`foreign-key "document_document_tokens" is nil for node %v`, n.ID)
+		}
+		node, ok := nodeids[*fk]
+		if !ok {
+			return fmt.Errorf(`unexpected foreign-key "document_document_tokens" returned %v for node %v`, *fk, n.ID)
+		}
+		assign(node, n)
+	}
+	return nil
+}
+func (dq *DocumentQuery) loadAttachments(ctx context.Context, query *AttachmentQuery, nodes []*Document, init func(*Document), assign func(*Document, *Attachment)) error {
+	fks := make([]driver.Value, 0, len(nodes))
+	nodeids := make(map[uuid.UUID]*Document)
+	for i := range nodes {
+		fks = append(fks, nodes[i].ID)
+		nodeids[nodes[i].ID] = nodes[i]
+		if init != nil {
+			init(nodes[i])
+		}
+	}
+	query.withFKs = true
+	query.Where(predicate.Attachment(func(s *sql.Selector) {
+		s.Where(sql.InValues(document.AttachmentsColumn, fks...))
+	}))
+	neighbors, err := query.All(ctx)
+	if err != nil {
+		return err
+	}
+	for _, n := range neighbors {
+		fk := n.document_attachments
+		if fk == nil {
+			return fmt.Errorf(`foreign-key "document_attachments" is nil for node %v`, n.ID)
+		}
+		node, ok := nodeids[*fk]
+		if !ok {
+			return fmt.Errorf(`unexpected foreign-key "document_attachments" returned %v for node %v`, *fk, n.ID)
+		}
+		assign(node, n)
+	}
+	return nil
+}
+
+func (dq *DocumentQuery) sqlCount(ctx context.Context) (int, error) {
+	_spec := dq.querySpec()
+	_spec.Node.Columns = dq.fields
+	if len(dq.fields) > 0 {
+		_spec.Unique = dq.unique != nil && *dq.unique
+	}
+	return sqlgraph.CountNodes(ctx, dq.driver, _spec)
+}
+
+func (dq *DocumentQuery) sqlExist(ctx context.Context) (bool, error) {
+	switch _, err := dq.FirstID(ctx); {
+	case IsNotFound(err):
+		return false, nil
+	case err != nil:
+		return false, fmt.Errorf("ent: check existence: %w", err)
+	default:
+		return true, nil
+	}
+}
+
+func (dq *DocumentQuery) querySpec() *sqlgraph.QuerySpec {
+	_spec := &sqlgraph.QuerySpec{
+		Node: &sqlgraph.NodeSpec{
+			Table:   document.Table,
+			Columns: document.Columns,
+			ID: &sqlgraph.FieldSpec{
+				Type:   field.TypeUUID,
+				Column: document.FieldID,
+			},
+		},
+		From:   dq.sql,
+		Unique: true,
+	}
+	if unique := dq.unique; unique != nil {
+		_spec.Unique = *unique
+	}
+	if fields := dq.fields; len(fields) > 0 {
+		_spec.Node.Columns = make([]string, 0, len(fields))
+		_spec.Node.Columns = append(_spec.Node.Columns, document.FieldID)
+		for i := range fields {
+			if fields[i] != document.FieldID {
+				_spec.Node.Columns = append(_spec.Node.Columns, fields[i])
+			}
+		}
+	}
+	if ps := dq.predicates; len(ps) > 0 {
+		_spec.Predicate = func(selector *sql.Selector) {
+			for i := range ps {
+				ps[i](selector)
+			}
+		}
+	}
+	if limit := dq.limit; limit != nil {
+		_spec.Limit = *limit
+	}
+	if offset := dq.offset; offset != nil {
+		_spec.Offset = *offset
+	}
+	if ps := dq.order; len(ps) > 0 {
+		_spec.Order = func(selector *sql.Selector) {
+			for i := range ps {
+				ps[i](selector)
+			}
+		}
+	}
+	return _spec
+}
+
+func (dq *DocumentQuery) sqlQuery(ctx context.Context) *sql.Selector {
+	builder := sql.Dialect(dq.driver.Dialect())
+	t1 := builder.Table(document.Table)
+	columns := dq.fields
+	if len(columns) == 0 {
+		columns = document.Columns
+	}
+	selector := builder.Select(t1.Columns(columns...)...).From(t1)
+	if dq.sql != nil {
+		selector = dq.sql
+		selector.Select(selector.Columns(columns...)...)
+	}
+	if dq.unique != nil && *dq.unique {
+		selector.Distinct()
+	}
+	for _, p := range dq.predicates {
+		p(selector)
+	}
+	for _, p := range dq.order {
+		p(selector)
+	}
+	if offset := dq.offset; offset != nil {
+		// limit is mandatory for offset clause. We start
+		// with default value, and override it below if needed.
+		selector.Offset(*offset).Limit(math.MaxInt32)
+	}
+	if limit := dq.limit; limit != nil {
+		selector.Limit(*limit)
+	}
+	return selector
+}
+
+// DocumentGroupBy is the group-by builder for Document entities.
+type DocumentGroupBy struct {
+	config
+	selector
+	fields []string
+	fns    []AggregateFunc
+	// intermediate query (i.e. traversal path).
+	sql  *sql.Selector
+	path func(context.Context) (*sql.Selector, error)
+}
+
+// Aggregate adds the given aggregation functions to the group-by query.
+func (dgb *DocumentGroupBy) Aggregate(fns ...AggregateFunc) *DocumentGroupBy {
+	dgb.fns = append(dgb.fns, fns...)
+	return dgb
+}
+
+// Scan applies the group-by query and scans the result into the given value.
+func (dgb *DocumentGroupBy) Scan(ctx context.Context, v any) error {
+	query, err := dgb.path(ctx)
+	if err != nil {
+		return err
+	}
+	dgb.sql = query
+	return dgb.sqlScan(ctx, v)
+}
+
+func (dgb *DocumentGroupBy) sqlScan(ctx context.Context, v any) error {
+	for _, f := range dgb.fields {
+		if !document.ValidColumn(f) {
+			return &ValidationError{Name: f, err: fmt.Errorf("invalid field %q for group-by", f)}
+		}
+	}
+	selector := dgb.sqlQuery()
+	if err := selector.Err(); err != nil {
+		return err
+	}
+	rows := &sql.Rows{}
+	query, args := selector.Query()
+	if err := dgb.driver.Query(ctx, query, args, rows); err != nil {
+		return err
+	}
+	defer rows.Close()
+	return sql.ScanSlice(rows, v)
+}
+
+func (dgb *DocumentGroupBy) sqlQuery() *sql.Selector {
+	selector := dgb.sql.Select()
+	aggregation := make([]string, 0, len(dgb.fns))
+	for _, fn := range dgb.fns {
+		aggregation = append(aggregation, fn(selector))
+	}
+	// If no columns were selected in a custom aggregation function, the default
+	// selection is the fields used for "group-by", and the aggregation functions.
+	if len(selector.SelectedColumns()) == 0 {
+		columns := make([]string, 0, len(dgb.fields)+len(dgb.fns))
+		for _, f := range dgb.fields {
+			columns = append(columns, selector.C(f))
+		}
+		columns = append(columns, aggregation...)
+		selector.Select(columns...)
+	}
+	return selector.GroupBy(selector.Columns(dgb.fields...)...)
+}
+
+// DocumentSelect is the builder for selecting fields of Document entities.
+type DocumentSelect struct {
+	*DocumentQuery
+	selector
+	// intermediate query (i.e. traversal path).
+	sql *sql.Selector
+}
+
+// Scan applies the selector query and scans the result into the given value.
+func (ds *DocumentSelect) Scan(ctx context.Context, v any) error {
+	if err := ds.prepareQuery(ctx); err != nil {
+		return err
+	}
+	ds.sql = ds.DocumentQuery.sqlQuery(ctx)
+	return ds.sqlScan(ctx, v)
+}
+
+func (ds *DocumentSelect) sqlScan(ctx context.Context, v any) error {
+	rows := &sql.Rows{}
+	query, args := ds.sql.Query()
+	if err := ds.driver.Query(ctx, query, args, rows); err != nil {
+		return err
+	}
+	defer rows.Close()
+	return sql.ScanSlice(rows, v)
+}