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MybatisPlus中QueryWrapper常用方法總結(jié)

更新時(shí)間：2023年07月26日 09:46:23 作者：fking86

MyBatis-Plus是一個(gè)Mybatis增強(qiáng)版工具，在MyBatis上擴(kuò)充了其他功能沒有改變其基本功能，為了簡(jiǎn)化開發(fā)提交效率而存在，queryWrapper是mybatis plus中實(shí)現(xiàn)查詢的對(duì)象封裝操作類，本文就給大家總結(jié)了MybatisPlus中QueryWrapper的常用方法,需要的朋友可以參考下

QueryWrapper常用方法列表

函數(shù)	說明	例子
eq	等于(=)	queryWrapper.eq(“user_name”, “張三”); //user_name=“張三”
ne	不等于(<>)	queryWrapper.ne(“user_name”, “張三”); //user_name<>“張三”
gt	大于(>)	queryWrapper.gt(“level”, 1); //level>1
ge	大于等于(>=)	queryWrapper.ge(“level”, 1); //level>=1
lt	小于(<)	queryWrapper.lt(“level”, 1); //level<1
le	小于等于(<=)	queryWrapper.le(“level”, 1); //level<=1
between	值1和值2之間	queryWrapper.between(“level”, 1,10); //level>=1 and level <=10
notBetween	不在值1和值2之間	queryWrapper.notBetween(“level”, 1,10);//level<1 or level >10
like	模糊匹配 like %值%	queryWrapper.like(“user_name”, “張三”); //user_name like “%張三%”
not like	不模糊匹配 not like %值%	queryWrapper.notLike(“user_name”, “張三”); //user_name not like “%張三%”
likeLeft	左模糊匹配 like %值	queryWrapper.likeLeft(“user_name”, “張三”); //user_name like “%張三”
likeRight	右模糊匹配 like 值%	queryWrapper.likeRight(“user_name”, “張三”); //user_name like “張三%”
isNull	字段為空	queryWrapper.isNull(“user_name”);//user_name is null
isNotNull	字段不為空	queryWrapper.isNotNull(“user_name”);//user_name is not null
in	字段 in (v0，v1，…)	queryWrapper.in(“user_name”, {“張三”,“李四”,“王五”}); // user_name in （“張三”,“李四”,“王五”）
notIn	字段 not in (v0，vl，…)	queryWrapper.notIn(“user_name”, {“張三”,“李四”,“王五”}); // user_name not in （“張三”,“李四”,“王五”）
inSql	字段 in ( sql語(yǔ)句)	queryWrapper.in(“user_name”, (select name from student where age< 23)); // user_name in (select name from student where age< 23)
notInSql	字段 not in ( sql語(yǔ)句)	queryWrapper.notIn(“user_name”, (select name from student where age< 23)); // user_name not in (select name from student where age< 23)
groupBy	分組:GROUP BY 字段	queryWrapper.groupBy(“user_name”);//group by user_name
orderByAsc	排序:ORDER BY 字段 ASC	queryWrapper.orderByAsc(“createTime”);//order by createTime asc
orderByDesc	排序:ORDER BY 字段 DESC	queryWrapper.orderByDesc(“createTime”);//order by createTime desc
orderBy	排序:ORDER BY 字段	queryWrapper.orderBy(true, true, “createTime”);//order by createTime asc
or	拼接 OR	說明:主動(dòng)調(diào)用or表示緊接著下一個(gè)方法不是用and連接!(不調(diào)用or則默認(rèn)為使用and連接);queryWrapper.eq(“id”, “1”).or().eq(“user_name”, “張三”); //id = 1 or name =‘張三’
and	拼接 AND	queryWrapper.eq(“id”, “1”).and(i->i.eq(“user_name”, “張三”)); //id = 1 and name =‘張三’
apply	拼接 sql	說明: 該方法可用于數(shù)據(jù)庫(kù)函數(shù)動(dòng)態(tài)入?yún)⒌膒arams;queryWrapper.eq(“id”, user.getId()).apply(“date_format(‘createTime’,‘%Y-%m-%d’) = {0}”,“2023-07-25”);//date_format(‘createTime’,'%Y-%m-%d) =‘2023-07-25’")
last	無(wú)視優(yōu)化規(guī)則直接拼接到 sql 的最后	說明:只能調(diào)用一次,多次調(diào)用以最后一次為準(zhǔn) 有sq1注入的風(fēng)險(xiǎn),請(qǐng)謹(jǐn)慎使用queryWrapper.last(" limit 1");// limit 1
exists	拼接 EXISTS(sql語(yǔ)句)	queryWrapper.exists(“SELECT id FROM Student WHERE User.id = Student.userId”);// exists (“SELECT id FROM Student WHERE User.id = Student.userId”)
notExists	拼接 NOT EXISTS (sg1語(yǔ)句)	queryWrapper.notExists(“SELECT id FROM Student WHERE User.id = Student.userId”);// not exists (“SELECT id FROM Student WHERE User.id = Student.userId”)
nested	正常嵌套不帶 AND或者 OR	queryWrapper.nested(i->i.eq(“id”,“1”).eq(“user_name”,“張三”));// id = 1 and user_name=“張三”
having	having ( sql語(yǔ)句)	queryWrapper.having(“sum(age) > {0}”,10);//having sum(age) > 10;

常用操作

1.插入

@Override
public void save(User user) {
    userMapper.insert(user);
}

2.根據(jù)id獲取

@Override
public User getById(String id) {
    return userMapper.selectById(id);
}

3.刪除

@Override
public void removeById(String id) {
    userMapper.deleteById(id);
}

4.根據(jù)id更新

userMapper.updateById(user);

5.獲取列表

userMapper.selectList(queryWrapper);

6.獲取單條數(shù)據(jù)

userMapper.selectOne(queryWrapper);

注意：

優(yōu)先順序：!>or>and所以and和or在一起，先計(jì)算or

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