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How to select date from datetime column?
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You can use MySQL's DATE() function:
WHERE DATE(datetime) = '2009-10-20'
You could also try this:
WHERE datetime LIKE '2009-10-20%'
See this answer for info on the performance implications of using LIKE.
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Best way to test if a row exists in a MySQL table
I'm trying to find out if a row exists in a table. Using MySQL, is it better to do a query like this:
12 Answers
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MySQL select 10 random rows from 600K rows fast
...imple, to gaps, to non-uniform with gaps.
http://jan.kneschke.de/projects/mysql/order-by-rand/
For most general case, here is how you do it:
SELECT name
FROM random AS r1 JOIN
(SELECT CEIL(RAND() *
(SELECT MAX(id)
FROM random)) AS id)
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How to document a method with parameter(s)?
...nts which is a compact, machine-readable syntax:
from typing import Dict, Union
def foo(i: int, d: Dict[str, Union[str, int]]) -> int:
"""
Explanation: this function takes two arguments: `i` and `d`.
`i` is annotated simply as `int`. `d` is a dictionary with `str` keys
and value...
App Inventor 2 计时器（Clock）详细用法示例 · App Inventor 2 中文网
...返回的当前时刻格式化成文本：
24小时格式怎么写？
如何定时一小时？
如何定点执行，比如到20:23分执行？
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计时器在界面设计中的哪里？
计时器怎么启动？
默认计时器是自动启用的，也可程序控制它的属...
When to use single quotes, double quotes, and backticks in MySQL
...le and column identifiers, but are only necessary when the identifier is a MySQL reserved keyword, or when the identifier contains whitespace characters or characters beyond a limited set (see below) It is often recommended to avoid using reserved keywords as column or table identifiers when possibl...
改用 443 端口连接 Github 修复 git push 时出现 Connection timed out 的...
...s.
不想改用 https 协议，因为 https 每次都要询问用户名，密码太烦了。最后找到了一个使用 443 端口连接 github 的方法：
修改 ~/.ssh/config 中 github.com 的配置， Hostname 改为 ssh.github.com, Port 改为 443:
Host github.com
Hostname ssh.github.c...
Get query from java.sql.PreparedStatement [duplicate]
...To my experience, the ones which do so are at least the PostgreSQL 8.x and MySQL 5.x JDBC drivers. For the case your JDBC driver doesn't support it, your best bet is using a statement wrapper which logs all setXxx() methods and finally populates a SQL string on toString() based on the logged informa...
App Inventor 2 列表代码块 · App Inventor 2 中文网
...用给定的变量名称 item 来引用当前列表项。
此处 是有关如何使用该块的教程。
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通过保持输入列表中的每个项目满足测试来创建一个新列表。
主体是一个布尔表达式，用于检查项目是否通过测试。
如果主体...
Inserting a Python datetime.datetime object into MySQL
I have a date column in a MySQL table. I want to insert a datetime.datetime() object into this column. What should I be using in the execute statement?
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