mybatis plus 的not equal

回答: 在MyBatis Plus中，要使用不等于（not equal）的条件查询，可以使用`ne`方法。例如，如果要查询name不等于某个值的记录，可以使用以下代码：

QueryWrapper<User> userWrapper = new QueryWrapper<>();
userWrapper.ne("name", value);

其中，`ne`方法表示不等于，第一个参数是字段名，第二个参数是要排除的值。[2]

另外，如果要使用Lambda表达式来构建查询条件，可以使用`lambda`方法和`ne`方法。例如，要查询name不等于某个值的记录，可以使用以下代码：

QueryWrapper<User> userWrapper = new QueryWrapper<>();
userWrapper.lambda().ne(User::getName, value);

其中，`lambda`方法表示使用Lambda表达式构建查询条件，`ne`方法表示不等于，第一个参数是字段的引用，第二个参数是要排除的值。[3]

综上所述，要在MyBatis Plus中使用不等于的条件查询，可以使用`ne`方法或Lambda表达式的`ne`方法。

相关问题

mybatis plus or括号

MyBatis Plus supports the OR condition using the `or` method provided by the `QueryWrapper` class. To use OR conditions with parentheses, you can chain multiple `or` methods together.

Here's an example:

QueryWrapper<Entity> queryWrapper = new QueryWrapper<>();
queryWrapper.eq("column1", value1)
    .or()
    .eq("column2", value2)
    .or()
    .nested(wrapper -> wrapper.eq("column3", value3).ne("column4", value4));

In the above example, `eq` represents the equal condition, `ne` represents the not equal condition, and `nested` is used to create a nested condition with parentheses.

You can adjust the conditions and column names based on your requirements.

mybatis plus querywrapper

MyBatis Plus QueryWrapper is a utility class provided by the MyBatis Plus framework to help in building complex database queries. It is used in conjunction with the MyBatis Plus Query API to construct criteria for selecting, updating, or deleting records from a database table.

QueryWrapper provides a fluent and intuitive API for constructing queries with various conditions such as equal, not equal, greater than, less than, between, like, and more. It also supports nested conditions and chaining multiple conditions together.

Here's an example of how to use QueryWrapper:

// Import the necessary classes
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.conditions.Wrapper;

// Create a QueryWrapper instance
QueryWrapper<User> queryWrapper = new QueryWrapper<>();

// Add conditions to the query
queryWrapper
    .eq("age", 25)
    .like("name", "John")
    .between("salary", 2000, 5000)
    .orderByAsc("age");

// Use the query wrapper in your MyBatis Plus query
List<User> userList = userMapper.selectList(queryWrapper);

In this example, we create a QueryWrapper instance and chain different conditions like `eq`, `like`, and `between` to construct the desired query. Finally, we pass the query wrapper to the `selectList` method of the MyBatis Plus mapper interface to execute the query.

You can find more information about QueryWrapper and other features of MyBatis Plus in their official documentation.