mybatis 之動態sql 增刪改查
====================== mybatis的動態SQL ============
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一、什麽是動態SQL呢？
就是where後面的條件不是確定的 根據用戶的選擇動態產生的sql就是動態sql。
1.1 動態sql之查詢 select
<select id="selectlike" parameterType="map" resultType="app_dynamicSql.User">
select * from t_user
<where>
<if test="pid!=null">
and id = #{pid}
</if>
<if test="pname!=null">
userName like #{pname}
</if>
</where>
</select>
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1.2動態sql之更新 update
update t_user set name = ? password = ?;
<update id="" parameterType="Map">
update t_user
<set>
<if test="pid!=null">
id = #{pid},
</test>
<if test="pname!=null">
name = #{name},
</test>
</set>
where id = #{pid}
</update>
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1.3 動態sql之刪除 delete 批量刪除
foreach 屬性詳解
collection 表示參數類型 比如是數組或者集合
open 表示以神符號開始
close 表示以什麽符號結束
separator 表示分隔符
item 表示要遍歷的名稱
<!-- 動態刪除之集合版本 -->
<delete id="dynaDeleteList">
delete from t_user where id in
<foreach collection="list" open="(" close=")" separator="," item="ids" >
#{ids}
</foreach>
</delete>
<!--動態刪除之數組版本-->
<delete id="dynaDeleteArray">
delete from t_user where id in
<foreach collection="參數類型" open="（" close="）" separator="," item="最好是形參名字">
#{最好是形參的名字}
</foreach>
</delete>
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1.4 動態sql之插入 inert
<sql id="key">
<trim suffixOverrides=",">
<if test="id!=null">
id,
</if>
...
</trim>
</sql>
<sql id="value">
<trim suffixOverrides=",">
<if test="id!=null">
#{id},
</if>
...
</trim>
</sql>
<insert id="dynaInsert" parameterType="參數類型">
insert into t_user(<include refid="key"></include>) values(<include refid="value"></include>)
</insert>
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XML配置文件
1 <?xml version="1.0" encoding="UTF-8" ?> 2 <!DOCTYPE mapper 3 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 4 "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> 5 6 <mapper namespace="dyanmicUser"> 7 8 <resultMap type="app_dynamicSql.User" id="dynamic_userMap"> 9 <id property="id" column="id"/> 10 11 <result property="userName" column="userName" /> 12 <result property="password" column="password" /> 13 </resultMap> 14 15 <!-- 動態查詢Sql --> 16 <select id="selectlike" parameterType="map" resultType="app_dynamicSql.User"> 17 select * from t_user 18 <where> 19 <if test="pid!=null"> 20 and id = #{pid} 21 </if> 22 <if test="pname!=null"> 23 userName like #{pname} 24 </if> 25 </where> 26 </select> 27 28 <!-- 動態sql之更新--> 29 <update id="dynaUpdate" parameterType="Map"> 30 update t_user 31 <set> 32 <if test="pname!=null"> 33 userName = #{pname}, 34 </if> 35 <if test="ppassword!=null"> 36 password = #{ppassword}, 37 </if> 38 </set> 39 where id = #{pid} 40 </update> 41 42 <!-- 動態刪除之數組版本 --> 43 <delete id="dynaDeleteArray"> 44 delete from t_user where id in 45 <!-- 用於叠代數組元素的標簽 46 collection表示類型 47 open表示開始的符號 48 close表示結束符號 49 separator表示元素之間的分隔符 50 item表示要叠代的數組 屬性值可以隨便寫但是建議與形參名相同 51 #{ids} 表示數組中的元素 52 --> 53 <foreach collection="array" open="(" close=")" separator="," item="ids" > 54 #{ids} 55 </foreach> 56 </delete> 57 58 <!-- 動態刪除之集合版本 --> 59 <delete id="dynaDeleteList"> 60 delete from t_user where id in 61 <foreach collection="list" open="(" close=")" separator="," item="ids" > 62 #{ids} 63 </foreach> 64 </delete> 65 66 67 68 <!-- 動態sql之插入 --> 69 70 <!-- sql片段對應的是字段名稱 --> 71 <sql id="key"> 72 <trim suffixOverrides=","> 73 <if test="id!=null"> 74 id, 75 </if> 76 <if test="userName!=null"> 77 userName, 78 </if> 79 <if test="password"> 80 password, 81 </if> 82 </trim> 83 </sql> 84 <!-- sql片段對應的是值 --> 85 <sql id="value"> 86 <!-- 去掉最後一個逗號 --> 87 <trim suffixOverrides=","> 88 <if test="id!=null"> 89 #{id}, 90 </if> 91 <if test="userName!=null"> 92 #{userName}, 93 </if> 94 <if test="password"> 95 #{password}, 96 </if> 97 </trim> 98 </sql> 99 100 101 <insert id="dynaInsert" parameterType="app_dynamicSql.User"> 102 <!-- 引用上面定義的sql片段 --> 103 insert into t_user(<include refid="key"></include>) values(<include refid="value"></include>) 104 105 </insert> 106 107 </mapper> 108
UserDao和測試代碼實例
1 package app_dynamicSql; 2 3 import java.util.ArrayList; 4 import java.util.LinkedHashMap; 5 import java.util.List; 6 import java.util.Map; 7 8 import org.apache.ibatis.session.SqlSession; 9 import org.junit.Test; 10 11 import utils.mybatisUtils; 12 13 public class UserDao { 14 15 /** 16 * 條件查詢所有用戶信息 17 * @param start 18 * @param size 19 * @return 20 * @throws Exception 21 */ 22 public List<User> findByPage(Integer id,String userName) throws Exception{ 23 24 SqlSession sqlSession = null; 25 List<User> list = new ArrayList<User>(); 26 27 try { 28 29 sqlSession = mybatisUtils.getSqlSession(); 30 31 Map<String,Object> map = new LinkedHashMap<String,Object>(); 32 map.put("pid", id); 33 map.put("pname", "%"+userName+"%"); 34 35 list = sqlSession.selectList("dyanmicUser.selectlike",map); 36 37 } catch (Exception e) { 38 e.printStackTrace(); 39 }finally{ 40 //關閉session 斷開連接 41 mybatisUtils.closerSqlSession(); 42 } 43 return list; 44 } 45 46 /** 47 * 條件更新用戶信息 48 * @param userName 49 * @param password 50 * @throws Exception 51 */ 52 public void dynaUpdate(Integer id,String userName,String password) throws Exception{ 53 SqlSession sqlSession = null; 54 try { 55 56 sqlSession = mybatisUtils.getSqlSession(); 57 58 Map<String,Object> map = new LinkedHashMap<String,Object>(); 59 map.put("pid", id); 60 map.put("pname", userName); 61 map.put("ppassword", password); 62 63 int count = sqlSession.update("dyanmicUser.dynaUpdate",map); 64 65 System.out.println("===========影響"+count+"行========"); 66 67 //提交事務 68 sqlSession.commit(); 69 } catch (Exception e) { 70 e.printStackTrace(); 71 //事務回滾 72 sqlSession.rollback(); 73 }finally{ 74 //關閉session 斷開連接 75 mybatisUtils.closerSqlSession(); 76 } 77 } 78 79 80 81 /** 82 * 根據ID批量刪除 （數組的方式） 83 * @param ids 84 * @throws Exception 85 */ 86 public void dynaDelete(int... ids) throws Exception{ 87 SqlSession sqlSession = null; 88 try { 89 90 sqlSession = mybatisUtils.getSqlSession(); 91 92 int count = sqlSession.delete("dyanmicUser.dynaDeleteArray", ids); 93 94 System.out.println("===========影響"+count+"行========"); 95 96 //提交事務 97 sqlSession.commit(); 98 } catch (Exception e) { 99 e.printStackTrace(); 100 //事務回滾 101 sqlSession.rollback(); 102 }finally{ 103 //關閉session 斷開連接 104 mybatisUtils.closerSqlSession(); 105 } 106 } 107 108 /** 109 * 根據ID批量刪除 （集合的方式） 110 * @param ids 111 * @throws Exception 112 */ 113 public void dynaDeleteList(List<Integer> ids) throws Exception{ 114 SqlSession sqlSession = null; 115 try { 116 117 sqlSession = mybatisUtils.getSqlSession(); 118 119 int count = sqlSession.delete("dyanmicUser.dynaDeleteList", ids); 120 121 System.out.println("===========影響"+count+"行========"); 122 123 //提交事務 124 sqlSession.commit(); 125 } catch (Exception e) { 126 e.printStackTrace(); 127 //事務回滾 128 sqlSession.rollback(); 129 }finally{ 130 //關閉session 斷開連接 131 mybatisUtils.closerSqlSession(); 132 } 133 } 134 135 /** 136 * 動態sql之插入 137 * @param user 138 * @throws Exception 139 */ 140 public void dynaInsert(User user) throws Exception{ 141 SqlSession sqlSession = null; 142 try { 143 144 sqlSession = mybatisUtils.getSqlSession(); 145 int count = sqlSession.insert("dyanmicUser.dynaInsert", user); 146 147 System.out.println("===========影響"+count+"行========"); 148 149 //提交事務 150 sqlSession.commit(); 151 } catch (Exception e) { 152 e.printStackTrace(); 153 //事務回滾 154 sqlSession.rollback(); 155 }finally{ 156 //關閉session 斷開連接 157 mybatisUtils.closerSqlSession(); 158 } 159 } 160 161 162 163 164 @Test 165 public void testFindByPage() throws Exception{ 166 UserDao userDao = new UserDao(); 167 168 List<User> list = userDao.findByPage(null,"測試"); 169 System.out.println("條件差詢結果："); 170 for(User user:list){ 171 System.out.println(user); 172 } 173 174 } 175 176 @Test 177 public void testDynaUpdate() throws Exception{ 178 UserDao userDao = new UserDao(); 179 // userDao.dynaUpdate(1,"測試222","ceshi222"); 180 userDao.dynaUpdate(11,null,"222"); 181 182 } 183 184 @Test 185 public void testDynaDelete() throws Exception{ 186 UserDao userdao = new UserDao(); 187 userdao.dynaDelete(1,3,5,7,77); 188 } 189 190 @Test 191 public void testDynaDeleteList() throws Exception{ 192 UserDao userdao = new UserDao(); 193 194 List<Integer> list = new ArrayList<Integer>(); 195 196 list.add(2); 197 list.add(4); 198 list.add(6); 199 200 userdao.dynaDeleteList(list); 201 202 } 203 204 @Test 205 public void testDynaInsert() throws Exception{ 206 UserDao userdao = new UserDao(); 207 userdao.dynaInsert(new User(11,null,null)); 208 } 209 210 }
mybatis 之動態sql 增刪改查