✅ 重点技巧总结

🔥 实战组合案例

LambdaQueryWrapper<User> queryWrapper = new LambdaQueryWrapper<>();
queryWrapper
    .eq(name != null, User::getName, name)
    .ne(status != null, User::getStatus, status)
    .gt(ageMin != null, User::getAge, ageMin)
    .lt(ageMax != null, User::getAge, ageMax)
    .like(email != null, User::getEmail, email)
    .in(!CollectionUtils.isEmpty(idList), User::getId, idList)
    .orderByAsc(User::getCreateTime)
    .orderByDesc(User::getAge);

支持：

• 条件自动忽略

• 批量 in 查询

• 多条件排序

• 灵活组合写法

🔨 推荐封装工具

你可以写一个 QueryWrapperUtils：

public class QueryWrapperUtils {
    public static <T> void safeEq(LambdaQueryWrapper<T> wrapper, SFunction<T, ?> column, Object value) {
        if (value != null) {
            wrapper.eq(column, value);
        }
    }
    public static <T> void safeIn(LambdaQueryWrapper<T> wrapper, SFunction<T, ?> column, Collection<?> values) {
        if (values != null && !values.isEmpty()) {
            wrapper.in(column, values);
        }
    }
}

这样可以优雅调用：

QueryWrapperUtils.safeEq(queryWrapper, User::getName, req.getName());
QueryWrapperUtils.safeIn(queryWrapper, User::getId, req.getIdList());