add

backend/src/main/java/com/nursinghome/mapper/BillMapper.java

@@ -0,0 +1,28 @@
+package com.nursinghome.mapper;
+
+import com.nursinghome.entity.Bill;
+import org.apache.ibatis.annotations.*;
+
+import java.util.List;
+
+@Mapper
+public interface BillMapper {
+    @Insert("INSERT INTO bill(elder_id, month, bed_fee, care_fee, meal_fee, other_fee, total, status, created_at) VALUES(#{elderId}, #{month}, #{bedFee}, #{careFee}, #{mealFee}, #{otherFee}, #{total}, #{status}, NOW())")
+    @Options(useGeneratedKeys = true, keyProperty = "id")
+    int insert(Bill bill);
+
+    @Select("SELECT * FROM bill ORDER BY month DESC")
+    List<Bill> listAll();
+
+    @Select("SELECT * FROM bill WHERE id = #{id}")
+    Bill findById(Long id);
+
+    @Select("SELECT * FROM bill WHERE elder_id = #{elderId} ORDER BY month DESC")
+    List<Bill> listByElderId(Long elderId);
+
+    @Select("<script>SELECT * FROM bill WHERE elder_id IN <foreach collection='elderIds' item='id' open='(' separator=',' close=')'>#{id}</foreach> ORDER BY month DESC</script>")
+    List<Bill> listByElderIds(@Param("elderIds") List<Long> elderIds);
+
+    @Update("UPDATE bill SET status=#{status}, paid_at=#{paidAt} WHERE id=#{id}")
+    int updateStatus(Bill bill);
+}