mybatispuls条件查询

MyBatis Plus provides various methods to perform conditional queries. Here's an example of how to perform a conditional query using MyBatis Plus:

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.baomidou.mybatisplus.extension.service.additional.query.impl.LambdaQueryChainWrapper;
import com.baomidou.mybatisplus.extension.service.additional.query.impl.QueryChainWrapper;

public class MyBatisPlusExample {

    public static void main(String[] args) {
        // Select query with conditions
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("age", 25)
                    .like("name", "John")
                    .orderByDesc("salary")
                    .last("LIMIT 10");

        // Select query using lambda expressions
        LambdaQueryWrapper<User> lambdaQueryWrapper = Wrappers.lambdaQuery();
        lambdaQueryWrapper.eq(User::getAge, 25)
                        .like(User::getName, "John")
                        .orderByDesc(User::getSalary)
                        .last("LIMIT 10");

        // Select query chain
        QueryChainWrapper<User> queryChainWrapper = new QueryChainWrapper<>(mybatisPlusMapper);
        queryChainWrapper.eq("age", 25)
                        .like("name", "John")
                        .orderByDesc("salary")
                        .last("LIMIT 10");

        // Execute the query
        List<User> userList = mybatisPlusMapper.selectList(queryWrapper);
    }
}

In the above example, we demonstrated three ways to perform a conditional query using MyBatis Plus. The `queryWrapper` allows you to build the query conditions using chained methods. The `lambdaQueryWrapper` uses lambda expressions to define the conditions. The `queryChainWrapper` provides a query chain style method to build the conditions.

You can customize the query conditions based on your requirements by using different methods provided by MyBatis Plus, such as `eq`, `ne`, `like`, `gt`, `lt`, `orderBy`, etc.