[{"createTime":1735734952000,"id":1,"img":"hwy_ms_500_252.jpeg","link":"https://activity.huaweicloud.com/cps.html?fromacct=261f35b6-af54-4511-a2ca-910fa15905d1&utm_source=V1g3MDY4NTY=&utm_medium=cps&utm_campaign=201905","name":"华为云秒杀","status":9,"txt":"华为云38元秒杀","type":1,"updateTime":1735747411000,"userId":3},{"createTime":1736173885000,"id":2,"img":"txy_480_300.png","link":"https://cloud.tencent.com/act/cps/redirect?redirect=1077&cps_key=edb15096bfff75effaaa8c8bb66138bd&from=console","name":"腾讯云秒杀","status":9,"txt":"腾讯云限量秒杀","type":1,"updateTime":1736173885000,"userId":3},{"createTime":1736177492000,"id":3,"img":"aly_251_140.png","link":"https://www.aliyun.com/minisite/goods?userCode=pwp8kmv3","memo":"","name":"阿里云","status":9,"txt":"阿里云2折起","type":1,"updateTime":1736177492000,"userId":3},{"createTime":1735660800000,"id":4,"img":"vultr_560_300.png","link":"https://www.vultr.com/?ref=9603742-8H","name":"Vultr","status":9,"txt":"Vultr送$100","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":5,"img":"jdy_663_320.jpg","link":"https://3.cn/2ay1-e5t","name":"京东云","status":9,"txt":"京东云特惠专区","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":6,"img":"new_ads.png","link":"https://www.iodraw.com/ads","name":"发布广告","status":9,"txt":"发布广告","type":1,"updateTime":1735660800000,"userId":3},{"createTime":1735660800000,"id":7,"img":"yun_910_50.png","link":"https://activity.huaweicloud.com/discount_area_v5/index.html?fromacct=261f35b6-af54-4511-a2ca-910fa15905d1&utm_source=aXhpYW95YW5nOA===&utm_medium=cps&utm_campaign=201905","name":"底部","status":9,"txt":"高性能云服务器2折起","type":2,"updateTime":1735660800000,"userId":3}]
在实际项目中,我们会经常对数据做一些模糊查询的操作,这时候就需要利用到 like
字段,那么在Mybatis中,有哪些方式可以实现模糊查询呢?这里就简单的介绍下:Mybatis模糊查询Like的三种方式,如果对你有帮助,码文不易,请一键三连,万分感谢。
方法一:直接传参法(手动拼接)
public void select1(String name) { String name = "%" + name+ "%"; UserDao.
getUserByName(name); }
Dao层:
// Dao层指定参数别名 List<User> getUserByName(@Param("name") String name);
mapper.xml层:
<select id="getUserByName" resultMap="result"> SELECT * FROM t_user WHERE name
LIKE #{name} </select>
注意:此方法可以完成模糊查询任务,但是不推荐,因为与Java代码耦合了,不利于维护和修改。
方法二: mysql的CONCAT()函数
Dao接口:
List<User> getUserByName(@Param("keyword") String keyword);
mapper.xml层:
* name LIKE CONCAT(‘%’,#{name},‘%’) <select id="getUserByName" resultMap=
"result"> SELECT * FROM t_user WHERE name LIKE CONCAT('%',#{name},'%') </select>
* name like “%”#{name}“%” <select id="getUserByName" resultMap="result">
SELECT * FROM t_user WHERE name like "%"#{name}"%" </select>
* name like “%”${name}“%”( 不建议可能会产生sql注入) <select id="getUserByName" resultMap
="result"> SELECT * FROM t_user WHERE name like "%"${name}"%" </select>
注意:执行效果与上面的直接传参一样,但比直接传参法更好,因为与代码解耦了,但是此方法只针对mysql数据库所用,如果换成Oracle数据库则需要修改sql代码,因此此方法不通用,但可以使用。
方法三:Mybatis的bind绑定
mybatis针对这种情况作出了调整,提供了一个bind元素,此元素可以跨越数据库限制,也就是说不管是mysql还是Oracle数据库都可以通用模糊查询。
Dao接口:
List<User> getUserByName(@Param("keyword") String keyword);
mapper.xml层:
<select id="getUserByName" resultMap="result"> <!--
name就是传入的参数,bind相当于是一个参数,这个参数的值就是value拼接出来的值--> <bind name="pattern" value="'%'
+ name + '%'" /> SELECT * FROM t_user WHERE name LIKE #{pattern} OR id LIKE #{
pattern} </select>