定义对应model

internal/infra/models/medication.go

@@ -66,3 +66,26 @@ type Medication struct {
 	Manufacturer                  string             `gorm:"size:100;comment:生产厂家" json:"manufacturer"`
 	Instructions                  datatypes.JSON     `gorm:"type:jsonb;comment:使用说明" json:"instructions"`
 }
+
+// MedicationReasonType 定义了用药原因
+type MedicationReasonType string
+
+const (
+	ReasonTypePreventive MedicationReasonType = "预防"
+	ReasonTypeTreatment  MedicationReasonType = "治疗"
+	ReasonTypeHealthCare MedicationReasonType = "保健"
+)
+
+// GroupMedicationLog 记录了对整个猪批次的用药情况
+type GroupMedicationLog struct {
+	gorm.Model
+	PigBatchID   uint                 `gorm:"not null;index;comment:关联的猪批次ID"`
+	MedicationID uint                 `gorm:"not null;index;comment:关联的药品ID"`
+	Medication   Medication           `gorm:"foreignKey:MedicationID"` // 预加载药品信息
+	DosageUsed   float64              `gorm:"not null;comment:使用的总剂量 (单位由药品决定,如g或ml)"`
+	TargetCount  int                  `gorm:"not null;comment:用药对象数量"`
+	Reason       MedicationReasonType `gorm:"size:20;not null;comment:用药原因"`
+	Description  string               `gorm:"size:255;comment:具体描述,如'治疗呼吸道病'"`
+	Operator     string               `gorm:"size:50;comment:操作员"`
+	HappenedAt   time.Time            `gorm:"not null;default:CURRENT_TIMESTAMP;comment:用药时间"`
+}