Initial commit: Material Texture API service

- Go + Gin + GORM + PostgreSQL backend
- RESTful API for material management
- Docker deployment support
- Database partitioning for billion-scale data
- API documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/repository/material.go

@@ -0,0 +1,99 @@
+package repository
+
+import (
+	"material_texture/internal/models"
+
+	"gorm.io/gorm"
+)
+
+type MaterialRepository struct {
+	db *gorm.DB
+}
+
+func NewMaterialRepository(db *gorm.DB) *MaterialRepository {
+	return &MaterialRepository{db: db}
+}
+
+// List 获取材质列表（支持分页和名称搜索）
+func (r *MaterialRepository) List(query models.MaterialListQuery) ([]models.Material, int64, error) {
+	var materials []models.Material
+	var total int64
+
+	db := r.db.Model(&models.Material{})
+
+	// 名称模糊搜索
+	if query.Name != "" {
+		db = db.Where("name ILIKE ?", "%"+query.Name+"%")
+	}
+
+	// 获取总数
+	if err := db.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+
+	// 分页查询
+	offset := (query.Page - 1) * query.PageSize
+	if err := db.Order("id DESC").Offset(offset).Limit(query.PageSize).Find(&materials).Error; err != nil {
+		return nil, 0, err
+	}
+
+	return materials, total, nil
+}
+
+// GetByID 根据ID获取单个材质
+func (r *MaterialRepository) GetByID(id int64) (*models.Material, error) {
+	var material models.Material
+	if err := r.db.First(&material, id).Error; err != nil {
+		return nil, err
+	}
+	return &material, nil
+}
+
+// Create 创建材质
+func (r *MaterialRepository) Create(material *models.Material) error {
+	return r.db.Create(material).Error
+}
+
+// Update 更新材质 (优化: 直接 UPDATE，返回影响行数)
+func (r *MaterialRepository) Update(material *models.Material) error {
+	return r.db.Save(material).Error
+}
+
+// UpdateByID 根据 ID 直接更新 (优化版本，减少查询)
+func (r *MaterialRepository) UpdateByID(id int64, updates map[string]interface{}) (int64, error) {
+	result := r.db.Model(&models.Material{}).Where("id = ?", id).Updates(updates)
+	return result.RowsAffected, result.Error
+}
+
+// UpdateByIDWithVersion 带乐观锁的更新 (防止并发覆盖)
+// 只有当 version 匹配时才更新，并自动递增 version
+func (r *MaterialRepository) UpdateByIDWithVersion(id int64, version int64, updates map[string]interface{}) (int64, error) {
+	// 在更新中自动递增 version
+	updates["version"] = gorm.Expr("version + 1")
+
+	result := r.db.Model(&models.Material{}).
+		Where("id = ? AND version = ?", id, version).
+		Updates(updates)
+
+	return result.RowsAffected, result.Error
+}
+
+// Delete 删除材质
+func (r *MaterialRepository) Delete(id int64) error {
+	return r.db.Delete(&models.Material{}, id).Error
+}
+
+// DeleteByID 删除材质并返回影响行数 (优化版本)
+func (r *MaterialRepository) DeleteByID(id int64) (int64, error) {
+	result := r.db.Delete(&models.Material{}, id)
+	return result.RowsAffected, result.Error
+}
+
+// Exists 检查材质是否存在
+func (r *MaterialRepository) Exists(id int64) (bool, error) {
+	var count int64
+	if err := r.db.Model(&models.Material{}).Where("id = ?", id).Count(&count).Error; err != nil {
+		return false, err
+	}
+	return count > 0, nil
+}