diff --git a/README.md b/README.md
index fd653c2..8eb10f7 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ NomadCode Core는 사용자 요청을 작업 단위로 받고, 작업 상태를
 - task 생성 / 조회 / 목록 / enqueue API
 - PostgreSQL 연결
 - goose migration
-- sqlc 기반 query 구조
+- sqlc 기반 DB query 생성 구조
 - River dummy job
 - Plane Adapter stub
 - Mattermost Adapter stub
@@ -100,6 +100,8 @@ sqlc 실행:
 ./bin/sqlc
 ```
 
+DB 접근 코드는 `migrations/`의 스키마와 `queries/`의 SQL을 기준으로 `internal/db/`에 생성합니다. `internal/db/db.go`, `internal/db/models.go`, `internal/db/tasks.sql.go`는 생성 파일이므로 직접 수정하지 않습니다.
+
 Docker Compose 실행은 통합 확인이 필요할 때 선택적으로 사용합니다.
 
 ```bash
diff --git a/internal/db/db.go b/internal/db/db.go
index 1a90c27..468d1fa 100644
--- a/internal/db/db.go
+++ b/internal/db/db.go
@@ -1,30 +1,32 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.31.1
+
 package db
 
 import (
 	"context"
-	"errors"
 
-	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgconn"
 )
 
-func NewPool(ctx context.Context, databaseURL string) (*pgxpool.Pool, error) {
-	if databaseURL == "" {
-		return nil, errors.New("DATABASE_URL is required")
-	}
-
-	cfg, err := pgxpool.ParseConfig(databaseURL)
-	if err != nil {
-		return nil, err
-	}
-
-	pool, err := pgxpool.NewWithConfig(ctx, cfg)
-	if err != nil {
-		return nil, err
-	}
-	if err := pool.Ping(ctx); err != nil {
-		pool.Close()
-		return nil, err
-	}
-
-	return pool, nil
+type DBTX interface {
+	Exec(context.Context, string, ...interface{}) (pgconn.CommandTag, error)
+	Query(context.Context, string, ...interface{}) (pgx.Rows, error)
+	QueryRow(context.Context, string, ...interface{}) pgx.Row
+}
+
+func New(db DBTX) *Queries {
+	return &Queries{db: db}
+}
+
+type Queries struct {
+	db DBTX
+}
+
+func (q *Queries) WithTx(tx pgx.Tx) *Queries {
+	return &Queries{
+		db: tx,
+	}
 }
diff --git a/internal/db/models.go b/internal/db/models.go
new file mode 100644
index 0000000..777c6aa
--- /dev/null
+++ b/internal/db/models.go
@@ -0,0 +1,22 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.31.1
+
+package db
+
+import (
+	"encoding/json"
+	"time"
+)
+
+type Task struct {
+	ID        string          `json:"id"`
+	Title     string          `json:"title"`
+	Source    string          `json:"source"`
+	Status    string          `json:"status"`
+	Payload   json.RawMessage `json:"payload"`
+	Result    json.RawMessage `json:"result"`
+	Error     *string         `json:"error"`
+	CreatedAt time.Time       `json:"created_at"`
+	UpdatedAt time.Time       `json:"updated_at"`
+}
diff --git a/internal/db/pool.go b/internal/db/pool.go
new file mode 100644
index 0000000..1a90c27
--- /dev/null
+++ b/internal/db/pool.go
@@ -0,0 +1,30 @@
+package db
+
+import (
+	"context"
+	"errors"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+func NewPool(ctx context.Context, databaseURL string) (*pgxpool.Pool, error) {
+	if databaseURL == "" {
+		return nil, errors.New("DATABASE_URL is required")
+	}
+
+	cfg, err := pgxpool.ParseConfig(databaseURL)
+	if err != nil {
+		return nil, err
+	}
+
+	pool, err := pgxpool.NewWithConfig(ctx, cfg)
+	if err != nil {
+		return nil, err
+	}
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		return nil, err
+	}
+
+	return pool, nil
+}
diff --git a/internal/db/queries.go b/internal/db/queries.go
deleted file mode 100644
index 0f4b954..0000000
--- a/internal/db/queries.go
+++ /dev/null
@@ -1,164 +0,0 @@
-// Code generated placeholder for sqlc-style queries. DO NOT EDIT lightly.
-package db
-
-import (
-	"context"
-	"encoding/json"
-	"time"
-
-	"github.com/jackc/pgx/v5"
-	"github.com/jackc/pgx/v5/pgconn"
-)
-
-type DBTX interface {
-	Exec(context.Context, string, ...any) (pgconn.CommandTag, error)
-	Query(context.Context, string, ...any) (pgx.Rows, error)
-	QueryRow(context.Context, string, ...any) pgx.Row
-}
-
-type Queries struct {
-	db DBTX
-}
-
-func New(db DBTX) *Queries {
-	return &Queries{db: db}
-}
-
-type Task struct {
-	ID        string          `json:"id"`
-	Title     string          `json:"title"`
-	Source    string          `json:"source"`
-	Status    string          `json:"status"`
-	Payload   json.RawMessage `json:"payload"`
-	Result    json.RawMessage `json:"result"`
-	Error     *string         `json:"error,omitempty"`
-	CreatedAt time.Time       `json:"created_at"`
-	UpdatedAt time.Time       `json:"updated_at"`
-}
-
-type CreateTaskParams struct {
-	Title   string          `json:"title"`
-	Source  string          `json:"source"`
-	Payload json.RawMessage `json:"payload"`
-}
-
-type UpdateTaskStatusParams struct {
-	ID     string `json:"id"`
-	Status string `json:"status"`
-}
-
-type CompleteTaskParams struct {
-	ID     string          `json:"id"`
-	Result json.RawMessage `json:"result"`
-}
-
-type FailTaskParams struct {
-	ID    string `json:"id"`
-	Error string `json:"error"`
-}
-
-const taskColumns = `
-	id::text,
-	title,
-	source,
-	status,
-	payload,
-	result,
-	error,
-	created_at,
-	updated_at
-`
-
-func (q *Queries) CreateTask(ctx context.Context, arg CreateTaskParams) (Task, error) {
-	row := q.db.QueryRow(ctx, `
-		INSERT INTO tasks (title, source, payload)
-		VALUES ($1, $2, $3)
-		RETURNING `+taskColumns, arg.Title, arg.Source, arg.Payload)
-	return scanTask(row)
-}
-
-func (q *Queries) GetTask(ctx context.Context, id string) (Task, error) {
-	row := q.db.QueryRow(ctx, `
-		SELECT `+taskColumns+`
-		FROM tasks
-		WHERE id::text = $1
-	`, id)
-	return scanTask(row)
-}
-
-func (q *Queries) ListTasks(ctx context.Context, limit int32) ([]Task, error) {
-	rows, err := q.db.Query(ctx, `
-		SELECT `+taskColumns+`
-		FROM tasks
-		ORDER BY created_at DESC
-		LIMIT $1
-	`, limit)
-	if err != nil {
-		return nil, err
-	}
-	defer rows.Close()
-
-	var tasks []Task
-	for rows.Next() {
-		task, err := scanTask(rows)
-		if err != nil {
-			return nil, err
-		}
-		tasks = append(tasks, task)
-	}
-	if err := rows.Err(); err != nil {
-		return nil, err
-	}
-
-	return tasks, nil
-}
-
-func (q *Queries) UpdateTaskStatus(ctx context.Context, arg UpdateTaskStatusParams) (Task, error) {
-	row := q.db.QueryRow(ctx, `
-		UPDATE tasks
-		SET status = $2, updated_at = now()
-		WHERE id::text = $1
-		RETURNING `+taskColumns, arg.ID, arg.Status)
-	return scanTask(row)
-}
-
-func (q *Queries) CompleteTask(ctx context.Context, arg CompleteTaskParams) (Task, error) {
-	row := q.db.QueryRow(ctx, `
-		UPDATE tasks
-		SET status = 'completed', result = $2, error = NULL, updated_at = now()
-		WHERE id::text = $1
-		RETURNING `+taskColumns, arg.ID, arg.Result)
-	return scanTask(row)
-}
-
-func (q *Queries) FailTask(ctx context.Context, arg FailTaskParams) (Task, error) {
-	row := q.db.QueryRow(ctx, `
-		UPDATE tasks
-		SET status = 'failed', error = $2, updated_at = now()
-		WHERE id::text = $1
-		RETURNING `+taskColumns, arg.ID, arg.Error)
-	return scanTask(row)
-}
-
-type taskScanner interface {
-	Scan(dest ...any) error
-}
-
-func scanTask(row taskScanner) (Task, error) {
-	var task Task
-	err := row.Scan(
-		&task.ID,
-		&task.Title,
-		&task.Source,
-		&task.Status,
-		&task.Payload,
-		&task.Result,
-		&task.Error,
-		&task.CreatedAt,
-		&task.UpdatedAt,
-	)
-	if err != nil {
-		return Task{}, err
-	}
-	return task, nil
-}
diff --git a/internal/db/tasks.sql.go b/internal/db/tasks.sql.go
new file mode 100644
index 0000000..4c8728d
--- /dev/null
+++ b/internal/db/tasks.sql.go
@@ -0,0 +1,187 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.31.1
+// source: tasks.sql
+
+package db
+
+import (
+	"context"
+	"encoding/json"
+)
+
+const completeTask = `-- name: CompleteTask :one
+UPDATE tasks
+SET status = 'completed', result = $2, error = NULL, updated_at = now()
+WHERE id::text = $1
+RETURNING id, title, source, status, payload, result, error, created_at, updated_at
+`
+
+type CompleteTaskParams struct {
+	ID     string          `json:"id"`
+	Result json.RawMessage `json:"result"`
+}
+
+func (q *Queries) CompleteTask(ctx context.Context, arg CompleteTaskParams) (Task, error) {
+	row := q.db.QueryRow(ctx, completeTask, arg.ID, arg.Result)
+	var i Task
+	err := row.Scan(
+		&i.ID,
+		&i.Title,
+		&i.Source,
+		&i.Status,
+		&i.Payload,
+		&i.Result,
+		&i.Error,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const createTask = `-- name: CreateTask :one
+INSERT INTO tasks (title, source, payload)
+VALUES ($1, $2, $3)
+RETURNING id, title, source, status, payload, result, error, created_at, updated_at
+`
+
+type CreateTaskParams struct {
+	Title   string          `json:"title"`
+	Source  string          `json:"source"`
+	Payload json.RawMessage `json:"payload"`
+}
+
+func (q *Queries) CreateTask(ctx context.Context, arg CreateTaskParams) (Task, error) {
+	row := q.db.QueryRow(ctx, createTask, arg.Title, arg.Source, arg.Payload)
+	var i Task
+	err := row.Scan(
+		&i.ID,
+		&i.Title,
+		&i.Source,
+		&i.Status,
+		&i.Payload,
+		&i.Result,
+		&i.Error,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const failTask = `-- name: FailTask :one
+UPDATE tasks
+SET status = 'failed', error = $2, updated_at = now()
+WHERE id::text = $1
+RETURNING id, title, source, status, payload, result, error, created_at, updated_at
+`
+
+type FailTaskParams struct {
+	ID    string  `json:"id"`
+	Error *string `json:"error"`
+}
+
+func (q *Queries) FailTask(ctx context.Context, arg FailTaskParams) (Task, error) {
+	row := q.db.QueryRow(ctx, failTask, arg.ID, arg.Error)
+	var i Task
+	err := row.Scan(
+		&i.ID,
+		&i.Title,
+		&i.Source,
+		&i.Status,
+		&i.Payload,
+		&i.Result,
+		&i.Error,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const getTask = `-- name: GetTask :one
+SELECT id, title, source, status, payload, result, error, created_at, updated_at
+FROM tasks
+WHERE id::text = $1
+`
+
+func (q *Queries) GetTask(ctx context.Context, id string) (Task, error) {
+	row := q.db.QueryRow(ctx, getTask, id)
+	var i Task
+	err := row.Scan(
+		&i.ID,
+		&i.Title,
+		&i.Source,
+		&i.Status,
+		&i.Payload,
+		&i.Result,
+		&i.Error,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const listTasks = `-- name: ListTasks :many
+SELECT id, title, source, status, payload, result, error, created_at, updated_at
+FROM tasks
+ORDER BY created_at DESC
+LIMIT $1
+`
+
+func (q *Queries) ListTasks(ctx context.Context, limit int32) ([]Task, error) {
+	rows, err := q.db.Query(ctx, listTasks, limit)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []Task
+	for rows.Next() {
+		var i Task
+		if err := rows.Scan(
+			&i.ID,
+			&i.Title,
+			&i.Source,
+			&i.Status,
+			&i.Payload,
+			&i.Result,
+			&i.Error,
+			&i.CreatedAt,
+			&i.UpdatedAt,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
+const updateTaskStatus = `-- name: UpdateTaskStatus :one
+UPDATE tasks
+SET status = $2, updated_at = now()
+WHERE id::text = $1
+RETURNING id, title, source, status, payload, result, error, created_at, updated_at
+`
+
+type UpdateTaskStatusParams struct {
+	ID     string `json:"id"`
+	Status string `json:"status"`
+}
+
+func (q *Queries) UpdateTaskStatus(ctx context.Context, arg UpdateTaskStatusParams) (Task, error) {
+	row := q.db.QueryRow(ctx, updateTaskStatus, arg.ID, arg.Status)
+	var i Task
+	err := row.Scan(
+		&i.ID,
+		&i.Title,
+		&i.Source,
+		&i.Status,
+		&i.Payload,
+		&i.Result,
+		&i.Error,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
diff --git a/internal/storage/store.go b/internal/storage/store.go
index 65453c6..857edc3 100644
--- a/internal/storage/store.go
+++ b/internal/storage/store.go
@@ -51,6 +51,6 @@ func (s *Store) CompleteTask(ctx context.Context, id string, result json.RawMess
 func (s *Store) FailTask(ctx context.Context, id, message string) (db.Task, error) {
 	return s.queries.FailTask(ctx, db.FailTaskParams{
 		ID:    id,
-		Error: message,
+		Error: &message,
 	})
 }
diff --git a/queries/tasks.sql b/queries/tasks.sql
index 1265254..2ef3f11 100644
--- a/queries/tasks.sql
+++ b/queries/tasks.sql
@@ -1,15 +1,15 @@
 -- name: CreateTask :one
 INSERT INTO tasks (title, source, payload)
 VALUES ($1, $2, $3)
-RETURNING *;
+RETURNING id, title, source, status, payload, result, error, created_at, updated_at;
 
 -- name: GetTask :one
-SELECT *
+SELECT id, title, source, status, payload, result, error, created_at, updated_at
 FROM tasks
 WHERE id::text = $1;
 
 -- name: ListTasks :many
-SELECT *
+SELECT id, title, source, status, payload, result, error, created_at, updated_at
 FROM tasks
 ORDER BY created_at DESC
 LIMIT $1;
@@ -18,16 +18,16 @@ LIMIT $1;
 UPDATE tasks
 SET status = $2, updated_at = now()
 WHERE id::text = $1
-RETURNING *;
+RETURNING id, title, source, status, payload, result, error, created_at, updated_at;
 
 -- name: CompleteTask :one
 UPDATE tasks
 SET status = 'completed', result = $2, error = NULL, updated_at = now()
 WHERE id::text = $1
-RETURNING *;
+RETURNING id, title, source, status, payload, result, error, created_at, updated_at;
 
 -- name: FailTask :one
 UPDATE tasks
 SET status = 'failed', error = $2, updated_at = now()
 WHERE id::text = $1
-RETURNING *;
+RETURNING id, title, source, status, payload, result, error, created_at, updated_at;
diff --git a/sqlc.yaml b/sqlc.yaml
index 8c2acf0..72bffa9 100644
--- a/sqlc.yaml
+++ b/sqlc.yaml
@@ -5,10 +5,11 @@ sql:
     queries: queries
     gen:
       go:
-        package: generated
-        out: internal/db/generated
+        package: db
+        out: internal/db
         sql_package: pgx/v5
         emit_json_tags: true
+        emit_pointers_for_null_types: true
         overrides:
           - db_type: uuid
             go_type: string
@@ -16,3 +17,7 @@ sql:
             go_type:
               import: encoding/json
               type: RawMessage
+          - db_type: timestamptz
+            go_type:
+              import: time
+              type: Time