5.28总结
今天完成了科技政策一点通的部分查询功能实现(在安卓端实现)
代码量:300
遇到困难:
sql语句的模糊查询的书写遇到了问题,不知如何去查询,
一般情况下:查询所有和条件查询使用两个方法(两个sql语句)实现
解决方法:分开写,分开调用
dao层语句
1 package com.lian.policy.Dao; 2 3 import com.lian.policy.bean.Policy; 4 import com.lian.policy.utils.DbOpenHelper; 5 6 import java.util.ArrayList; 7 import java.util.List; 8 9 public class PolicyDao extends DbOpenHelper { 10 //type是政策类型,range是政策实行的范围 11 public List<Policy> selectPoilcy(String type,String range,String text) 12 { 13 14 List<Policy> list=new ArrayList<>(); 15 try { 16 getConnection(); 17 String sql="select * from policy WHERE name LIKE '%" + type + "%'"; 18 pstmt=conn.prepareStatement(sql); 19 //pstmt.setString(1,type); 20 // if(type!=null){ 21 // sql+="and type like '%" + type + "%'"; 22 // } 23 // 24 // if(range!=null){ 25 // sql+="and range like '%" + range + "%'"; 26 // } 27 // if(text!=null){ 28 // sql+="and text like '%" + text + "%'"; 29 // } 30 rs=pstmt.executeQuery(); 31 while(rs.next()){ 32 Policy policy=new Policy(); 33 policy.setRange(rs.getString("range")); 34 policy.setText(rs.getString("text")); 35 policy.setType(rs.getString("type")); 36 policy.setName(rs.getString("name")); 37 policy.setId(rs.getLong("id")); 38 list.add(policy); 39 } 40 }catch (Exception e){ 41 e.printStackTrace(); 42 }finally { 43 closeAll(); 44 } 45 return list; 46 } 47 48 49 50 51 public List<Policy> selectAll() 52 { 53 54 List<Policy> list=new ArrayList<>(); 55 try { 56 getConnection(); 57 58 String sql="select * from policy"; 59 pstmt=conn.prepareStatement(sql); 60 //pstmt.setString(1,type); 61 // if(type!=null){ 62 // sql+="and type like '%" + type + "%'"; 63 // } 64 // 65 // if(range!=null){ 66 // sql+="and range like '%" + range + "%'"; 67 // } 68 // if(text!=null){ 69 // sql+="and text like '%" + text + "%'"; 70 // } 71 rs=pstmt.executeQuery(); 72 while(rs.next()){ 73 Policy policy=new Policy(); 74 policy.setRange(rs.getString("range")); 75 policy.setText(rs.getString("text")); 76 policy.setType(rs.getString("type")); 77 policy.setName(rs.getString("name")); 78 policy.setId(rs.getLong("id")); 79 list.add(policy); 80 } 81 }catch (Exception e){ 82 e.printStackTrace(); 83 }finally { 84 closeAll(); 85 } 86 return list; 87 } 88 }