依據https://www.cnblogs.com/suphowe/p/13157474.html 進行修改
一、mapper\TestMapper.xml
1、if語句
<!-- 使用if進行條件判斷,where 元素只會在子元素返回任何內容的情況下才插入 "WHERE" 子句。-->
<!-- 而且,若子句的開頭為 “AND” 或 “OR”,where 元素也會將它們去除 -->
<select id="findByNameUseIf" resultType="com.soft.entity.Test">
select * from sys_test
<where>
<if test="name != null">
and name=#{name}
</if>
</where>
</select>
2、like查詢
<!-- like 查詢 -->
<select id="findByNameUseLike" resultType="com.soft.entity.Test">
select * from sys_test
<where>
<if test="name != null">
and name like concat('%',#{name},'%')
</if>
</where>
</select>
3、Choose、When、Otherwise
<!-- 傳入了 “user” 就按 “user” 查找,傳入了 “name” 就按 “name” 查找,傳入了 “tel” 就按 “tel” 查找的情形。-->
<!-- 若三者都沒有傳入,就返回標記為 1=1 的 BLOG -->
<select id="findUseChooseWhenOtherwise" resultType="com.soft.entity.Test">
select * from sys_test where 1=1
<choose>
<when test="user != null">
and user=#{title}
</when>
<when test="name != null">
and name=#{name}
</when>
<when test="tel != null">
and tel like concat('%',#{tel},'%')
</when>
<otherwise>
and 1 = 1
</otherwise>
</choose>
</select>
4、Set
<!-- set 元素可以用於動態包含需要更新的列,忽略其它不更新的列 -->
<update id="updateSysTestUseSet" parameterType="com.soft.entity.Test">
update sys_test
<set>
<if test="user != null">user=#{user},</if>
<if test="name != null">name=#{name},</if>
<if test="tel != null">tel=#{tel}</if>
</set>
where id=#{id}
</update>
二、Java代碼
com\soft\dao\MybatisTestMapper.java
新增:
List<Test> findByNameUseIf(Test test);
List<Test> findByNameUseLike(Test test);
List<Test> findUseChooseWhenOtherwise(Test test);
int updateSysTestUseSet(Test test);
com\soft\service\impl\MybatisTestServiceImpl.java
新增:
@Override
public List<Test> findByNameUseIf(String name) {
Test test = new Test();
test.setName(name);
return mybatisTestMapper.findByNameUseIf(test);
}
@Override
public List<Test> findByNameUseLike(String name) {
Test test = new Test();
test.setName(name);
return mybatisTestMapper.findByNameUseLike(test);
}
@Override
public List<Test> findUseChooseWhenOtherwise(String user, String name, String tel) {
Test test = new Test();
test.setUser(user);
test.setName(name);
test.setTel(tel);
return mybatisTestMapper.findUseChooseWhenOtherwise(test);
}
@Override
public HashMap<String, Object> updateSysTestUseSet(int id, String user, String name, String tel) {
Test test = new Test();
test.setId(id);
test.setUser(user);
test.setName(name);
test.setTel(tel);
int result = mybatisTestMapper.updateSysTestUseSet(test);
HashMap<String, Object> returnMap = new HashMap<>(1);
returnMap.put("count", result);
return returnMap;
}
com\soft\service\IMybatisServiceTest.java
新增:
List<Test> findByNameUseIf(String name);
List<Test> findByNameUseLike(String name);
List<Test> findUseChooseWhenOtherwise(String user, String name, String tel);
HashMap<String, Object> updateSysTestUseSet(int id, String user, String name, String tel);
com\soft\controller\MybatisTestController.java
新增:
@RequestMapping(value = "/findByNameUseIf", method = RequestMethod.POST)
@ApiOperation(value = "Mybatis查詢測試,動態Sql,if語句", notes = "按名稱查詢")
@ApiImplicitParams({
@ApiImplicitParam(paramType = "query", name = "name", value = "name", dataType = "String")
})
public String findByNameUseIf(String name) {
List<Test> list = mybatisServiceTest.findByNameUseIf(name);
HashMap<String, Object> result = new HashMap<>();
bsUtil.createReturnMsg(result, 200, list);
return new Gson().toJson(result);
}
@RequestMapping(value = "/findByNameUseLike", method = RequestMethod.POST)
@ApiOperation(value = "Mybatis查詢測試,動態Sql,Like寫法", notes = "按名稱查詢")
@ApiImplicitParams({
@ApiImplicitParam(paramType = "query", name = "name", value = "name", dataType = "String")
})
public String findByNameUseLike(String name) {
List<Test> list = mybatisServiceTest.findByNameUseLike(name);
HashMap<String, Object> result = new HashMap<>();
bsUtil.createReturnMsg(result, 200, list);
return new Gson().toJson(result);
}
@RequestMapping(value = "/findUseChooseWhenOtherwise", method = RequestMethod.POST)
@ApiOperation(value = "Mybatis查詢測試,動態Sql,choose、when、otherwise", notes = "查詢")
@ApiImplicitParams({
@ApiImplicitParam(paramType = "query", name = "user", value = "user", dataType = "String"),
@ApiImplicitParam(paramType = "query", name = "name", value = "name", dataType = "String"),
@ApiImplicitParam(paramType = "query", name = "tel", value = "tel", dataType = "String")
})
public String findUseChooseWhenOtherwise(String user, String name, String tel) {
List<Test> list = mybatisServiceTest.findUseChooseWhenOtherwise(user, name, tel);
HashMap<String, Object> result = new HashMap<>();
bsUtil.createReturnMsg(result, 200, list);
return new Gson().toJson(result);
}
@RequestMapping(value = "/updateSysTestUseSet", method = RequestMethod.POST)
@ApiOperation(value = "Mybatis測試,動態Sql,使用Set", notes = "修改")
@ApiImplicitParams({
@ApiImplicitParam(paramType = "query", name = "id", value = "id", dataType = "int"),
@ApiImplicitParam(paramType = "query", name = "user", value = "user", dataType = "String"),
@ApiImplicitParam(paramType = "query", name = "name", value = "name", dataType = "String"),
@ApiImplicitParam(paramType = "query", name = "tel", value = "tel", dataType = "String")
})
public String updateSysTestUseSet(int id, String user, String name, String tel) {
HashMap<String, Object> updateSysTest = mybatisServiceTest.updateSysTestUseSet(id, user, name, tel);
HashMap<String, Object> result = new HashMap<>();
bsUtil.createReturnMsg(result, 200, updateSysTest);
return new Gson().toJson(result);
}
三、測試
1、if測試

2、like測試

3、choose、when、otherwise


4、set

