Include nested content counts in exam-prep catalog list response.

Add units, modules, and lessons aggregate counts per catalog course so clients can render hierarchy depth without extra API calls.

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

db/query/exam_prep_catalog_courses.sql

@@ -17,6 +17,17 @@ FROM exam_prep.catalog_courses
 WHERE id = $1;
 
 -- name: ExamPrepListCatalogCourses :many
+WITH catalog_course_counts AS (
+    SELECT
+        u.catalog_course_id,
+        COUNT(DISTINCT u.id)::BIGINT AS units_count,
+        COUNT(DISTINCT m.id)::BIGINT AS modules_count,
+        COUNT(DISTINCT l.id)::BIGINT AS lessons_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
+    GROUP BY u.catalog_course_id
+)
 SELECT
     COUNT(*) OVER () AS total_count,
     c.id,
@@ -24,9 +35,13 @@ SELECT
     c.description,
     c.thumbnail,
     c.sort_order,
+    COALESCE(cc.units_count, 0)::BIGINT AS units_count,
+    COALESCE(cc.modules_count, 0)::BIGINT AS modules_count,
+    COALESCE(cc.lessons_count, 0)::BIGINT AS lessons_count,
     c.created_at,
     c.updated_at
 FROM exam_prep.catalog_courses c
+LEFT JOIN catalog_course_counts cc ON cc.catalog_course_id = c.id
 ORDER BY c.sort_order ASC, c.id ASC
 LIMIT $1 OFFSET $2;
 

gen/db/exam_prep_catalog_courses.sql.go

@@ -105,6 +105,17 @@ func (q *Queries) ExamPrepListAllCatalogCourseIDs(ctx context.Context) ([]int64,
 }
 
 const ExamPrepListCatalogCourses = `-- name: ExamPrepListCatalogCourses :many
+WITH catalog_course_counts AS (
+    SELECT
+        u.catalog_course_id,
+        COUNT(DISTINCT u.id)::BIGINT AS units_count,
+        COUNT(DISTINCT m.id)::BIGINT AS modules_count,
+        COUNT(DISTINCT l.id)::BIGINT AS lessons_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
+    GROUP BY u.catalog_course_id
+)
 SELECT
     COUNT(*) OVER () AS total_count,
     c.id,
@@ -112,9 +123,13 @@ SELECT
     c.description,
     c.thumbnail,
     c.sort_order,
+    COALESCE(cc.units_count, 0)::BIGINT AS units_count,
+    COALESCE(cc.modules_count, 0)::BIGINT AS modules_count,
+    COALESCE(cc.lessons_count, 0)::BIGINT AS lessons_count,
     c.created_at,
     c.updated_at
 FROM exam_prep.catalog_courses c
+LEFT JOIN catalog_course_counts cc ON cc.catalog_course_id = c.id
 ORDER BY c.sort_order ASC, c.id ASC
 LIMIT $1 OFFSET $2
 `
@@ -125,14 +140,17 @@ type ExamPrepListCatalogCoursesParams struct {
 }
 
 type ExamPrepListCatalogCoursesRow struct {
-	TotalCount  int64              `json:"total_count"`
-	ID          int64              `json:"id"`
-	Name        string             `json:"name"`
-	Description pgtype.Text        `json:"description"`
-	Thumbnail   pgtype.Text        `json:"thumbnail"`
-	SortOrder   int32              `json:"sort_order"`
-	CreatedAt   pgtype.Timestamptz `json:"created_at"`
-	UpdatedAt   pgtype.Timestamptz `json:"updated_at"`
+	TotalCount   int64              `json:"total_count"`
+	ID           int64              `json:"id"`
+	Name         string             `json:"name"`
+	Description  pgtype.Text        `json:"description"`
+	Thumbnail    pgtype.Text        `json:"thumbnail"`
+	SortOrder    int32              `json:"sort_order"`
+	UnitsCount   int64              `json:"units_count"`
+	ModulesCount int64              `json:"modules_count"`
+	LessonsCount int64              `json:"lessons_count"`
+	CreatedAt    pgtype.Timestamptz `json:"created_at"`
+	UpdatedAt    pgtype.Timestamptz `json:"updated_at"`
 }
 
 func (q *Queries) ExamPrepListCatalogCourses(ctx context.Context, arg ExamPrepListCatalogCoursesParams) ([]ExamPrepListCatalogCoursesRow, error) {
@@ -151,6 +169,9 @@ func (q *Queries) ExamPrepListCatalogCourses(ctx context.Context, arg ExamPrepLi
 			&i.Description,
 			&i.Thumbnail,
 			&i.SortOrder,
+			&i.UnitsCount,
+			&i.ModulesCount,
+			&i.LessonsCount,
 			&i.CreatedAt,
 			&i.UpdatedAt,
 		); err != nil {

internal/domain/exam_prep_catalog_course.go

@@ -4,13 +4,16 @@ import "time"
 
 // ExamPrepCatalogCourse is a top-level exam-prep track (e.g. DET, IELTS) in schema exam_prep — separate from LMS Learn English courses.
 type ExamPrepCatalogCourse struct {
-	ID          int64      `json:"id"`
-	Name        string     `json:"name"`
-	Description *string    `json:"description,omitempty"`
-	Thumbnail   *string    `json:"thumbnail,omitempty"`
-	SortOrder   int        `json:"sort_order"`
-	CreatedAt   time.Time  `json:"created_at"`
-	UpdatedAt   *time.Time `json:"updated_at,omitempty"`
+	ID           int64      `json:"id"`
+	Name         string     `json:"name"`
+	Description  *string    `json:"description,omitempty"`
+	Thumbnail    *string    `json:"thumbnail,omitempty"`
+	SortOrder    int        `json:"sort_order"`
+	UnitsCount   *int64     `json:"units_count,omitempty"`
+	ModulesCount *int64     `json:"modules_count,omitempty"`
+	LessonsCount *int64     `json:"lessons_count,omitempty"`
+	CreatedAt    time.Time  `json:"created_at"`
+	UpdatedAt    *time.Time `json:"updated_at,omitempty"`
 }
 
 type CreateExamPrepCatalogCourseInput struct {

internal/repository/exam_prep_catalog_courses.go

@@ -67,7 +67,7 @@ func (s *Store) ListExamPrepCatalogCourses(ctx context.Context, limit, offset in
 		if i == 0 {
 			total = r.TotalCount
 		}
-		out = append(out, examPrepCatalogCourseToDomain(dbgen.ExamPrepCatalogCourse{
+		item := examPrepCatalogCourseToDomain(dbgen.ExamPrepCatalogCourse{
 			ID:          r.ID,
 			Name:        r.Name,
 			Description: r.Description,
@@ -75,7 +75,11 @@ func (s *Store) ListExamPrepCatalogCourses(ctx context.Context, limit, offset in
 			SortOrder:   r.SortOrder,
 			CreatedAt:   r.CreatedAt,
 			UpdatedAt:   r.UpdatedAt,
-		}))
+		})
+		item.UnitsCount = &r.UnitsCount
+		item.ModulesCount = &r.ModulesCount
+		item.LessonsCount = &r.LessonsCount
+		out = append(out, item)
 	}
 	return out, total, nil
 }