Mybatis plus QueryWrapper的简单用法

墨蓝 2022-12-30 14:00 190阅读 0赞

<table> 
 <tbody> 
 <tr> 
 <td> 查询方式 </td> 
 <td> 说明 </td> 
 </tr> 
 <tr> 
 <td> setSqlSelect </td> 
 <td> 设置 SELECT 查询字段 </td> 
 </tr> 
 <tr> 
 <td> where </td> 
 <td> WHERE 语句，拼接 +?WHERE 条件 </td> 
 </tr> 
 <tr> 
 <td> and </td> 
 <td> AND 语句，拼接 +?AND 字段=值 </td> 
 </tr> 
 <tr> 
 <td> andNew </td> 
 <td> AND 语句，拼接 +?AND (字段=值) </td> 
 </tr> 
 <tr> 
 <td> or </td> 
 <td> OR 语句，拼接 +?OR 字段=值 </td> 
 </tr> 
 <tr> 
 <td> orNew </td> 
 <td> OR 语句，拼接 +?OR (字段=值) </td> 
 </tr> 
 <tr> 
 <td> eq </td> 
 <td> 等于= </td> 
 </tr> 
 <tr> 
 <td> allEq </td> 
 <td> 基于 map 内容等于= </td> 
 </tr> 
 <tr> 
 <td> ne </td> 
 <td> 不等于&lt;&gt; </td> 
 </tr> 
 <tr> 
 <td> gt </td> 
 <td> 大于&gt; </td> 
 </tr> 
 <tr> 
 <td> ge </td> 
 <td> 大于等于&gt;= </td> 
 </tr> 
 <tr> 
 <td> lt </td> 
 <td> 小于&lt; </td> 
 </tr> 
 <tr> 
 <td> le </td> 
 <td> 小于等于&lt;= </td> 
 </tr> 
 <tr> 
 <td> like </td> 
 <td> 模糊查询 LIKE </td> 
 </tr> 
 <tr> 
 <td> notLike </td> 
 <td> 模糊查询 NOT LIKE </td> 
 </tr> 
 <tr> 
 <td> in </td> 
 <td> IN 查询 </td> 
 </tr> 
 <tr> 
 <td> notIn </td> 
 <td> NOT IN 查询 </td> 
 </tr> 
 <tr> 
 <td> isNull </td> 
 <td> NULL 值查询 </td> 
 </tr> 
 <tr> 
 <td> isNotNull </td> 
 <td> IS NOT NULL </td> 
 </tr> 
 <tr> 
 <td> groupBy </td> 
 <td> 分组 GROUP BY </td> 
 </tr> 
 <tr> 
 <td> having </td> 
 <td> HAVING 关键词 </td> 
 </tr> 
 <tr> 
 <td> orderBy </td> 
 <td> 排序 ORDER BY </td> 
 </tr> 
 <tr> 
 <td> orderAsc </td> 
 <td> ASC 排序 ORDER BY </td> 
 </tr> 
 <tr> 
 <td> orderDesc </td> 
 <td> DESC 排序 ORDER BY </td> 
 </tr> 
 <tr> 
 <td> exists </td> 
 <td> EXISTS 条件语句 </td> 
 </tr> 
 <tr> 
 <td> notExists </td> 
 <td> NOT EXISTS 条件语句 </td> 
 </tr> 
 <tr> 
 <td> between </td> 
 <td> BETWEEN 条件语句 </td> 
 </tr> 
 <tr> 
 <td> notBetween </td> 
 <td> NOT BETWEEN 条件语句 </td> 
 </tr> 
 <tr> 
 <td> addFilter </td> 
 <td> 自由拼接 SQL </td> 
 </tr> 
 <tr> 
 <td> last </td> 
 <td> 拼接在最后，例如：last(“LIMIT 1”) </td> 
 </tr> 
 </tbody> 
</table>

public User getByIdNumber(Long idNumber) {
 QueryWrapper<User> queryWrapper = new QueryWrapper();
 queryWrapper.lambda()
 .eq(User::getIdNumber, idNumber)
 .gt(User::getIdAuthStatus, 0);
 return userMapper.selectOne(queryWrapper);
 }

and ( pid = 0 or pid is null)  用法

QueryWrapper<Resource> queryWrapper = new QueryWrapper();
 queryWrapper.and(wrapper -> wrapper.eq("pid", "0").or().isNull("pid"));
 queryWrapper.orderByAsc("sort");
 List<Resource> list = resourceMapper.selectList(queryWrapper);