zynqIOFP_VTT
时间: 2023-09-08 16:16:39 浏览: 47
ZynqIOFP_VTT是一种电源电压转换器(Voltage Translator)的命名。它通常用于Xilinx Zynq SoC平台上的IO (输入输出) 设备。这个转换器的功能是将高电压引脚和低电压引脚之间的信号进行电平转换,以确保正确的信号传输和兼容性。它可以确保IO设备在不同电源和电平之间正常工作,并且在系统中提供信号适配能力。
相关问题
SELECT ac.id,SUM( vtti.volunteer_time_value ) AS total_time FROM activity_check ac JOIN volunteer_time_table vtt ON vtt.activity_id = ac.id JOIN volunteer_time_table vtt ON vtt.id = vtti.volunteer_time_table_id WHERE ac.deleted = 0 vtt.deleted = 0 vtti.deleted = 0 ORDER BY total_time DESC LIMIT 10;哪里有问题
这段SQL语句有些语法错误。首先,在第3行和第4行中,都有JOIN volunteer_time_table vtt,这是重复定义了,应该修改其中一个为JOIN volunteer_time_table vtti。其次,在WHERE子句中,多个条件之间应该用AND或OR连接,这里缺少了这些连接符。最后,在SELECT语句中,应该在SUM函数后面添加AS total_time,以为这个计算的结果命名。因此,正确的SQL语句应该是:
```
SELECT ac.id, SUM(vtti.volunteer_time_value) AS total_time
FROM activity_check ac
JOIN volunteer_time_table vtt ON vtt.activity_id = ac.id
JOIN volunteer_time_table vtti ON vtti.id = vtt.volunteer_time_table_id
WHERE ac.deleted = 0 AND vtt.deleted = 0 AND vtti.deleted = 0
GROUP BY ac.id
ORDER BY total_time DESC
LIMIT 10;
```
这个语句的改动包括:修改第3行的JOIN语句,添加了GROUP BY子句,修改WHERE子句中多个条件之间的连接方式,添加了AS关键字。
SELECT DISTINCT s.student_num, s.student_name, '计算机学院' AS college_name, c.class_name, FROM student_info s JOIN classes c ON s.college_id = c.college_id JOIN volunteer_time_table_item t ON s.student_num = t.student_num JOIN volunteer_time_table vtt ON vtt.id = t.volunteer_time_table_id WHERE c.college_id = 1 AND s.level = 2021 AND t.deleted = 0 AND s.deleted = 0 AND vtt.deleted = 0 AND c.deleted = 0 ORDER BY t.volunteer_time_value DESC LIMIT 5;哪里有问题
在SELECT语句中,'计算机学院' AS college_name后面有一个逗号,应该将逗号删除,修改后的语句如下:
SELECT DISTINCT s.student_num, s.student_name, '计算机学院' AS college_name, c.class_name FROM student_info s JOIN classes c ON s.college_id = c.college_id JOIN volunteer_time_table_item t ON s.student_num = t.student_num JOIN volunteer_time_table vtt ON vtt.id = t.volunteer_time_table_id WHERE c.college_id = 1 AND s.level = 2021 AND t.deleted = 0 AND s.deleted = 0 AND vtt.deleted = 0 AND c.deleted = 0 ORDER BY t.volunteer_time_value DESC LIMIT 5;