admin select information(service and mapper layer)

Closes #19 (closed)

src/main/java/com/cardiff/client_project/mapper/CommonAdminHospitalMapper.java

+package com.cardiff.client_project.mapper;
+
+import com.cardiff.client_project.pojo.dto.HospitalDTO;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.jdbc.core.BeanPropertyRowMapper;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+
+@Repository
+public class CommonAdminHospitalMapper {
+
+    @Autowired
+    JdbcTemplate jdbcTemplate;
+
+    // 查询所有医院信息
+    public List<HospitalDTO> findAll() {
+        String sql = "SELECT * FROM hospital";
+        return jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(HospitalDTO.class));
+    }
+
+    // 添加医院信息
+    public int save(HospitalDTO hospital) {
+        String sql = "INSERT INTO hospital (name, location, phone, totalBeds, availableBeds, occupancyRate) VALUES (?, ?, ?, ?, ?, ?)";
+        return jdbcTemplate.update(sql, hospital.getName(), hospital.getLocation(), hospital.getPhone(), hospital.getTotalBeds(), hospital.getAvailableBeds(), hospital.getOccupancyRate());
+    }
+
+    // 更新医院信息
+    public int update(HospitalDTO hospital) {
+        String sql = "UPDATE hospital SET name=?, location=?, phone=?, totalBeds=?, availableBeds=?, occupancyRate=? WHERE id=?";
+        return jdbcTemplate.update(sql, hospital.getName(), hospital.getLocation(), hospital.getPhone(), hospital.getTotalBeds(), hospital.getAvailableBeds(), hospital.getOccupancyRate(), hospital.getId());
+    }
+
+    // 根据 ID 删除医院信息
+    public int deleteById(int id) {
+        String sql = "DELETE FROM hospital WHERE id=?";
+        return jdbcTemplate.update(sql, id);
+    }
+}