Include nested module, lesson, and practice counts in exam-prep units list response.

Expose per-unit aggregate counts under catalog-course units listing so clients can display unit depth without extra chained requests.

Co-authored-by: Cursor <cursoragent@cursor.com>

db/query/exam_prep_units.sql

@@ -29,6 +29,18 @@ ORDER BY
     u.id;
 
 -- name: ExamPrepListUnitsByCatalogCourse :many
+WITH unit_counts AS (
+    SELECT
+        u.id AS unit_id,
+        COUNT(DISTINCT m.id)::BIGINT AS modules_count,
+        COUNT(DISTINCT l.id)::BIGINT AS lessons_count,
+        COUNT(DISTINCT p.id)::BIGINT AS practices_count
+    FROM exam_prep.units u
+    LEFT JOIN exam_prep.unit_modules m ON m.unit_id = u.id
+    LEFT JOIN exam_prep.unit_module_lessons l ON l.unit_module_id = m.id
+    LEFT JOIN exam_prep.lesson_practices p ON p.unit_module_lesson_id = l.id
+    GROUP BY u.id
+)
 SELECT
     COUNT(*) OVER () AS total_count,
     u.id,
@@ -37,9 +49,13 @@ SELECT
     u.description,
     u.thumbnail,
     u.sort_order,
+    COALESCE(uc.modules_count, 0)::BIGINT AS modules_count,
+    COALESCE(uc.lessons_count, 0)::BIGINT AS lessons_count,
+    COALESCE(uc.practices_count, 0)::BIGINT AS practices_count,
     u.created_at,
     u.updated_at
 FROM exam_prep.units u
+LEFT JOIN unit_counts uc ON uc.unit_id = u.id
 WHERE
     u.catalog_course_id = $1
 ORDER BY

gen/db/exam_prep_units.sql.go

@@ -119,6 +119,18 @@ func (q *Queries) ExamPrepListUnitIDsByCatalogCourse(ctx context.Context, catalo
 }
 
 const ExamPrepListUnitsByCatalogCourse = `-- name: ExamPrepListUnitsByCatalogCourse :many
+WITH unit_counts AS (
+    SELECT
+        u.id AS unit_id,
+        COUNT(DISTINCT m.id)::BIGINT AS modules_count,
+        COUNT(DISTINCT l.id)::BIGINT AS lessons_count,
+        COUNT(DISTINCT p.id)::BIGINT AS practices_count
+    FROM exam_prep.units u
+    LEFT JOIN exam_prep.unit_modules m ON m.unit_id = u.id
+    LEFT JOIN exam_prep.unit_module_lessons l ON l.unit_module_id = m.id
+    LEFT JOIN exam_prep.lesson_practices p ON p.unit_module_lesson_id = l.id
+    GROUP BY u.id
+)
 SELECT
     COUNT(*) OVER () AS total_count,
     u.id,
@@ -127,9 +139,13 @@ SELECT
     u.description,
     u.thumbnail,
     u.sort_order,
+    COALESCE(uc.modules_count, 0)::BIGINT AS modules_count,
+    COALESCE(uc.lessons_count, 0)::BIGINT AS lessons_count,
+    COALESCE(uc.practices_count, 0)::BIGINT AS practices_count,
     u.created_at,
     u.updated_at
 FROM exam_prep.units u
+LEFT JOIN unit_counts uc ON uc.unit_id = u.id
 WHERE
     u.catalog_course_id = $1
 ORDER BY
@@ -153,6 +169,9 @@ type ExamPrepListUnitsByCatalogCourseRow struct {
 	Description     pgtype.Text        `json:"description"`
 	Thumbnail       pgtype.Text        `json:"thumbnail"`
 	SortOrder       int32              `json:"sort_order"`
+	ModulesCount    int64              `json:"modules_count"`
+	LessonsCount    int64              `json:"lessons_count"`
+	PracticesCount  int64              `json:"practices_count"`
 	CreatedAt       pgtype.Timestamptz `json:"created_at"`
 	UpdatedAt       pgtype.Timestamptz `json:"updated_at"`
 }
@@ -174,6 +193,9 @@ func (q *Queries) ExamPrepListUnitsByCatalogCourse(ctx context.Context, arg Exam
 			&i.Description,
 			&i.Thumbnail,
 			&i.SortOrder,
+			&i.ModulesCount,
+			&i.LessonsCount,
+			&i.PracticesCount,
 			&i.CreatedAt,
 			&i.UpdatedAt,
 		); err != nil {

internal/domain/exam_prep_unit.go

@@ -5,11 +5,14 @@ import "time"
 // ExamPrepUnit is a chapter-like grouping under an exam-prep catalog course (schema exam_prep.units).
 type ExamPrepUnit struct {
 	ID              int64      `json:"id"`
-	CatalogCourseID int64    `json:"catalog_course_id"`
+	CatalogCourseID int64      `json:"catalog_course_id"`
 	Name            string     `json:"name"`
 	Description     *string    `json:"description,omitempty"`
 	Thumbnail       *string    `json:"thumbnail,omitempty"`
 	SortOrder       int        `json:"sort_order"`
+	ModulesCount    *int64     `json:"modules_count,omitempty"`
+	LessonsCount    *int64     `json:"lessons_count,omitempty"`
+	PracticesCount  *int64     `json:"practices_count,omitempty"`
 	CreatedAt       time.Time  `json:"created_at"`
 	UpdatedAt       *time.Time `json:"updated_at,omitempty"`
 }

internal/repository/exam_prep_units.go

@@ -55,8 +55,8 @@ func (s *Store) GetExamPrepUnitByID(ctx context.Context, id int64) (domain.ExamP
 func (s *Store) ListExamPrepUnitsByCatalogCourse(ctx context.Context, catalogCourseID int64, limit, offset int32) ([]domain.ExamPrepUnit, int64, error) {
 	rows, err := s.queries.ExamPrepListUnitsByCatalogCourse(ctx, dbgen.ExamPrepListUnitsByCatalogCourseParams{
 		CatalogCourseID: catalogCourseID,
-		Limit:             limit,
+		Limit:           limit,
-		Offset:            offset,
+		Offset:          offset,
 	})
 	if err != nil {
 		return nil, 0, err
@@ -70,7 +70,7 @@ func (s *Store) ListExamPrepUnitsByCatalogCourse(ctx context.Context, catalogCou
 		if i == 0 {
 			total = r.TotalCount
 		}
-		out = append(out, examPrepUnitToDomain(dbgen.ExamPrepUnit{
+		item := examPrepUnitToDomain(dbgen.ExamPrepUnit{
 			ID:              r.ID,
 			CatalogCourseID: r.CatalogCourseID,
 			Name:            r.Name,
@@ -79,7 +79,11 @@ func (s *Store) ListExamPrepUnitsByCatalogCourse(ctx context.Context, catalogCou
 			SortOrder:       r.SortOrder,
 			CreatedAt:       r.CreatedAt,
 			UpdatedAt:       r.UpdatedAt,
-		}))
+		})
+		item.ModulesCount = &r.ModulesCount
+		item.LessonsCount = &r.LessonsCount
+		item.PracticesCount = &r.PracticesCount
+		out = append(out, item)
 	}
 	return out, total, nil
 }