大约有 19,000 项符合查询结果(耗时:0.0197秒) [XML]
如何实现心电图曲线 - App Inventor 2 中文网 - 清泛IT社区,为创新赋能!
本帖最后由 chenweigang 于 2024-06-21 17:03 编辑
我想做一个采集数据,显示曲线的app,类似下图显示心电图和心率这样的曲线,请问需要用什么控件实现,如果实现多条曲线又该怎么办?
简单的图表使用原生组件可以实现:
有...
How do you set a default value for a MySQL Datetime column?
How do you set a default value for a MySQL Datetime column?
25 Answers
25
...
PDO closing connection
Just a rather simple question with regards to PDO compared to MySQLi.
5 Answers
5
...
insert multiple rows via a php array into mysql
I'm passing a large dataset into a MySQL table via PHP using insert commands and I'm wondering if its possible to insert approximately 1000 rows at a time via a query other than appending each value on the end of a mile long string and then executing it. I am using the CodeIgniter framework so its f...
Multiple Updates in MySQL
...e, is there a way to update multiple rows at once (as in, in one query) in MySQL?
17 Answers
...
In MySQL, can I copy one row to insert into the same table?
...o you don't have to worry about the primary key. Setting it to null allows MySQL to choose the value itself, so there's no risk of creating a duplicate.
If you want to be super-sure you're only getting one row to insert, you could add LIMIT 1 to the end of the INSERT INTO line.
Note that I also ap...
Adding a public key to ~/.ssh/authorized_keys does not log me in automatically
...ider the excellent http://www.fail2ban.org
8. Extra
SSH tunnel to access a MySQL (bind = 127.0.0.1) server
share
|
improve this answer
|
follow
|
...
Is there a MySQL option/feature to track history of changes to records?
I've been asked if I can keep track of the changes to the records in a MySQL database. So when a field has been changed, the old vs new is available and the date this took place. Is there a feature or common technique to do this?
...
MySQL - UPDATE query based on SELECT Query
...
You can actually do this one of two ways:
MySQL update join syntax:
UPDATE tableA a
INNER JOIN tableB b ON a.name_a = b.name_b
SET validation_check = if(start_dts > end_dts, 'VALID', '')
-- where clause can go here
ANSI SQL syntax:
UPDATE tableA SET validation...
What is the maximum value for an int32?
...e who accidentally stored the phone number as an INT instead of VARCHAR in MySQL.
– Zarel
Feb 9 '11 at 2:00
8
...