目录
常用写法
自定义sql
补充: 查询条件中使用函数apply
补充: 末尾sql追加last
补充:排序
常用写法
xxxDO=实体类, 相当于:
select name, id from xxx group by name where delete_flag = 0 and status = 0
LambdaQueryWrapper<xxxDO> queryWrapper = Wrappers.lambdaQuery();
1、错误日志如下:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [spring/spring-datasource-mysql.xml]: Invocation of init method failed; nested exception is java.lang.Nul