新增语言学习后台服务

- 分类管理：支持分类的增删改查
- 单词管理：支持单词的增删改查，包含音标、释义、例句等字段
- 更新 README 项目说明

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/internal/repository/db.go

@@ -0,0 +1,21 @@
+package repository
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// NewPool creates a new pgx connection pool.
+func NewPool(ctx context.Context, databaseURL string) (*pgxpool.Pool, error) {
+	pool, err := pgxpool.New(ctx, databaseURL)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create connection pool: %w", err)
+	}
+	if err := pool.Ping(ctx); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("failed to ping database: %w", err)
+	}
+	return pool, nil
+}

backend/internal/repository/queries/category.sql.go

@@ -0,0 +1,122 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.31.1
+// source: category.sql
+
+package queries
+
+import (
+	"context"
+)
+
+const createCategory = `-- name: CreateCategory :one
+INSERT INTO categories (name, sort_order)
+VALUES ($1, $2)
+RETURNING id, name, sort_order, created_at, updated_at
+`
+
+type CreateCategoryParams struct {
+	Name      string `json:"name"`
+	SortOrder int32  `json:"sort_order"`
+}
+
+func (q *Queries) CreateCategory(ctx context.Context, arg CreateCategoryParams) (Category, error) {
+	row := q.db.QueryRow(ctx, createCategory, arg.Name, arg.SortOrder)
+	var i Category
+	err := row.Scan(
+		&i.ID,
+		&i.Name,
+		&i.SortOrder,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const deleteCategory = `-- name: DeleteCategory :exec
+DELETE FROM categories WHERE id = $1
+`
+
+func (q *Queries) DeleteCategory(ctx context.Context, id int32) error {
+	_, err := q.db.Exec(ctx, deleteCategory, id)
+	return err
+}
+
+const getCategory = `-- name: GetCategory :one
+SELECT id, name, sort_order, created_at, updated_at
+FROM categories
+WHERE id = $1
+`
+
+func (q *Queries) GetCategory(ctx context.Context, id int32) (Category, error) {
+	row := q.db.QueryRow(ctx, getCategory, id)
+	var i Category
+	err := row.Scan(
+		&i.ID,
+		&i.Name,
+		&i.SortOrder,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const listCategories = `-- name: ListCategories :many
+SELECT id, name, sort_order, created_at, updated_at
+FROM categories
+ORDER BY sort_order ASC, id ASC
+`
+
+func (q *Queries) ListCategories(ctx context.Context) ([]Category, error) {
+	rows, err := q.db.Query(ctx, listCategories)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	items := []Category{}
+	for rows.Next() {
+		var i Category
+		if err := rows.Scan(
+			&i.ID,
+			&i.Name,
+			&i.SortOrder,
+			&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 updateCategory = `-- name: UpdateCategory :one
+UPDATE categories
+SET name = $2,
+    sort_order = $3,
+    updated_at = NOW()
+WHERE id = $1
+RETURNING id, name, sort_order, created_at, updated_at
+`
+
+type UpdateCategoryParams struct {
+	ID        int32  `json:"id"`
+	Name      string `json:"name"`
+	SortOrder int32  `json:"sort_order"`
+}
+
+func (q *Queries) UpdateCategory(ctx context.Context, arg UpdateCategoryParams) (Category, error) {
+	row := q.db.QueryRow(ctx, updateCategory, arg.ID, arg.Name, arg.SortOrder)
+	var i Category
+	err := row.Scan(
+		&i.ID,
+		&i.Name,
+		&i.SortOrder,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}

backend/internal/repository/queries/db.go

@@ -0,0 +1,32 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.31.1
+
+package queries
+
+import (
+	"context"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgconn"
+)
+
+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,
+	}
+}

backend/internal/repository/queries/models.go

@@ -0,0 +1,31 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.31.1
+
+package queries
+
+import (
+	"time"
+)
+
+type Category struct {
+	ID        int32     `json:"id"`
+	Name      string    `json:"name"`
+	SortOrder int32     `json:"sort_order"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+}
+
+type Word struct {
+	ID              int32     `json:"id"`
+	CategoryID      int32     `json:"category_id"`
+	Word            string    `json:"word"`
+	Translation     string    `json:"translation"`
+	Phonetic        *string   `json:"phonetic"`
+	ExampleSentence *string   `json:"example_sentence"`
+	AudioUrl        *string   `json:"audio_url"`
+	ImageUrl        *string   `json:"image_url"`
+	SortOrder       int32     `json:"sort_order"`
+	CreatedAt       time.Time `json:"created_at"`
+	UpdatedAt       time.Time `json:"updated_at"`
+}

backend/internal/repository/queries/querier.go

@@ -0,0 +1,25 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.31.1
+
+package queries
+
+import (
+	"context"
+)
+
+type Querier interface {
+	CountWords(ctx context.Context, arg CountWordsParams) (int64, error)
+	CreateCategory(ctx context.Context, arg CreateCategoryParams) (Category, error)
+	CreateWord(ctx context.Context, arg CreateWordParams) (Word, error)
+	DeleteCategory(ctx context.Context, id int32) error
+	DeleteWord(ctx context.Context, id int32) error
+	GetCategory(ctx context.Context, id int32) (Category, error)
+	GetWord(ctx context.Context, id int32) (Word, error)
+	ListCategories(ctx context.Context) ([]Category, error)
+	ListWords(ctx context.Context, arg ListWordsParams) ([]Word, error)
+	UpdateCategory(ctx context.Context, arg UpdateCategoryParams) (Category, error)
+	UpdateWord(ctx context.Context, arg UpdateWordParams) (Word, error)
+}
+
+var _ Querier = (*Queries)(nil)

backend/internal/repository/queries/word.sql.go

@@ -0,0 +1,227 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.31.1
+// source: word.sql
+
+package queries
+
+import (
+	"context"
+)
+
+const countWords = `-- name: CountWords :one
+SELECT COUNT(*) AS total
+FROM words w
+WHERE
+    ($1::int = 0 OR w.category_id = $1)
+    AND ($2::text = '' OR w.word ILIKE '%' || $2 || '%' OR w.translation ILIKE '%' || $2 || '%')
+`
+
+type CountWordsParams struct {
+	CategoryID int32  `json:"category_id"`
+	Keyword    string `json:"keyword"`
+}
+
+func (q *Queries) CountWords(ctx context.Context, arg CountWordsParams) (int64, error) {
+	row := q.db.QueryRow(ctx, countWords, arg.CategoryID, arg.Keyword)
+	var total int64
+	err := row.Scan(&total)
+	return total, err
+}
+
+const createWord = `-- name: CreateWord :one
+INSERT INTO words (category_id, word, translation, phonetic, example_sentence, audio_url, image_url, sort_order)
+VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
+RETURNING id, category_id, word, translation, phonetic,
+          example_sentence, audio_url, image_url, sort_order,
+          created_at, updated_at
+`
+
+type CreateWordParams struct {
+	CategoryID      int32   `json:"category_id"`
+	Word            string  `json:"word"`
+	Translation     string  `json:"translation"`
+	Phonetic        *string `json:"phonetic"`
+	ExampleSentence *string `json:"example_sentence"`
+	AudioUrl        *string `json:"audio_url"`
+	ImageUrl        *string `json:"image_url"`
+	SortOrder       int32   `json:"sort_order"`
+}
+
+func (q *Queries) CreateWord(ctx context.Context, arg CreateWordParams) (Word, error) {
+	row := q.db.QueryRow(ctx, createWord,
+		arg.CategoryID,
+		arg.Word,
+		arg.Translation,
+		arg.Phonetic,
+		arg.ExampleSentence,
+		arg.AudioUrl,
+		arg.ImageUrl,
+		arg.SortOrder,
+	)
+	var i Word
+	err := row.Scan(
+		&i.ID,
+		&i.CategoryID,
+		&i.Word,
+		&i.Translation,
+		&i.Phonetic,
+		&i.ExampleSentence,
+		&i.AudioUrl,
+		&i.ImageUrl,
+		&i.SortOrder,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const deleteWord = `-- name: DeleteWord :exec
+DELETE FROM words WHERE id = $1
+`
+
+func (q *Queries) DeleteWord(ctx context.Context, id int32) error {
+	_, err := q.db.Exec(ctx, deleteWord, id)
+	return err
+}
+
+const getWord = `-- name: GetWord :one
+SELECT id, category_id, word, translation, phonetic,
+       example_sentence, audio_url, image_url, sort_order,
+       created_at, updated_at
+FROM words
+WHERE id = $1
+`
+
+func (q *Queries) GetWord(ctx context.Context, id int32) (Word, error) {
+	row := q.db.QueryRow(ctx, getWord, id)
+	var i Word
+	err := row.Scan(
+		&i.ID,
+		&i.CategoryID,
+		&i.Word,
+		&i.Translation,
+		&i.Phonetic,
+		&i.ExampleSentence,
+		&i.AudioUrl,
+		&i.ImageUrl,
+		&i.SortOrder,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}
+
+const listWords = `-- name: ListWords :many
+SELECT w.id, w.category_id, w.word, w.translation, w.phonetic,
+       w.example_sentence, w.audio_url, w.image_url, w.sort_order,
+       w.created_at, w.updated_at
+FROM words w
+WHERE
+    ($3::int = 0 OR w.category_id = $3)
+    AND ($4::text = '' OR w.word ILIKE '%' || $4 || '%' OR w.translation ILIKE '%' || $4 || '%')
+ORDER BY w.sort_order ASC, w.id ASC
+LIMIT $1 OFFSET $2
+`
+
+type ListWordsParams struct {
+	Limit      int32  `json:"limit"`
+	Offset     int32  `json:"offset"`
+	CategoryID int32  `json:"category_id"`
+	Keyword    string `json:"keyword"`
+}
+
+func (q *Queries) ListWords(ctx context.Context, arg ListWordsParams) ([]Word, error) {
+	rows, err := q.db.Query(ctx, listWords,
+		arg.Limit,
+		arg.Offset,
+		arg.CategoryID,
+		arg.Keyword,
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	items := []Word{}
+	for rows.Next() {
+		var i Word
+		if err := rows.Scan(
+			&i.ID,
+			&i.CategoryID,
+			&i.Word,
+			&i.Translation,
+			&i.Phonetic,
+			&i.ExampleSentence,
+			&i.AudioUrl,
+			&i.ImageUrl,
+			&i.SortOrder,
+			&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 updateWord = `-- name: UpdateWord :one
+UPDATE words
+SET category_id = $2,
+    word = $3,
+    translation = $4,
+    phonetic = $5,
+    example_sentence = $6,
+    audio_url = $7,
+    image_url = $8,
+    sort_order = $9,
+    updated_at = NOW()
+WHERE id = $1
+RETURNING id, category_id, word, translation, phonetic,
+          example_sentence, audio_url, image_url, sort_order,
+          created_at, updated_at
+`
+
+type UpdateWordParams struct {
+	ID              int32   `json:"id"`
+	CategoryID      int32   `json:"category_id"`
+	Word            string  `json:"word"`
+	Translation     string  `json:"translation"`
+	Phonetic        *string `json:"phonetic"`
+	ExampleSentence *string `json:"example_sentence"`
+	AudioUrl        *string `json:"audio_url"`
+	ImageUrl        *string `json:"image_url"`
+	SortOrder       int32   `json:"sort_order"`
+}
+
+func (q *Queries) UpdateWord(ctx context.Context, arg UpdateWordParams) (Word, error) {
+	row := q.db.QueryRow(ctx, updateWord,
+		arg.ID,
+		arg.CategoryID,
+		arg.Word,
+		arg.Translation,
+		arg.Phonetic,
+		arg.ExampleSentence,
+		arg.AudioUrl,
+		arg.ImageUrl,
+		arg.SortOrder,
+	)
+	var i Word
+	err := row.Scan(
+		&i.ID,
+		&i.CategoryID,
+		&i.Word,
+		&i.Translation,
+		&i.Phonetic,
+		&i.ExampleSentence,
+		&i.AudioUrl,
+		&i.ImageUrl,
+		&i.SortOrder,
+		&i.CreatedAt,
+		&i.UpdatedAt,
+	)
+	return i, err
+}