大约有 7,000 项符合查询结果（耗时：0.0233秒） [XML]
Is there a good reason I see VARCHAR(255) used so often (as opposed to another length)?
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@CharlesBretana: By "fake UTF-8" I mean MySQL's "utf8" encoding, which as I mentioned reserves (and is limited to) 3 bytes per character. This isn't a very good version of UTF-8; if you want decent UTF-8 in MySQL, you have to use its "utf8mb4" encoding. But peopl...
MySQL Query - Records between Today and Last 30 Days
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You can also write this in mysql -
SELECT DATE_FORMAT(create_date, '%m/%d/%Y')
FROM mytable
WHERE create_date < DATE_ADD(NOW(), INTERVAL -1 MONTH);
FIXED
share
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How do I insert NULL values using PDO?
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I had trouble with PDO::PARAM_NULL on MySql 5.1.53, but PDO::PARAM_INT with a null value worked great.
– Will Shaver
Dec 5 '11 at 19:33
2
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一个科技公司只是碰巧卖起了披萨？ - 资讯 - 清泛网 - 专注C/C++及内核技术
...执行送餐，最高时速可达每小时12.5公里。顾客可以通过密码解锁，打开DRU自助取餐。
2016年4月，达美乐又推出新App一键下单——“一键”的意思是：“点开App，而不需任何其他操作”，10秒内倒计时确认非误操作，就会完成下...
INSERT INTO…SELECT for all MySQL columns
...%2f%2fstackoverflow.com%2fquestions%2f5253302%2finsert-into-select-for-all-mysql-columns%23new-answer', 'question_page');
}
);
Post as a guest
Name
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Best practices for SQL varchar column length [closed]
... table's varchar column. But I could not find any reference for that.
For MySQL the manual says "In most cases, ALTER TABLE makes a temporary copy of the original table". And my own tests confirm that: running an ALTER TABLE on a table with 1.2 million rows (the same as in my test with Postgres) to...
count(*) vs count(column-name) - which is more correct? [duplicate]
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there is a performance difference (at least in MySQL) as well (see my answer).
– nickf
Jun 9 '10 at 7:51
1
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常用Sql - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
常用Sqlmysql：drop table if exists tablename;不能写成drop table tablename if exists tablename;mysql：建立索引SqlCREATE TABLE t...mysql：drop table if exists tablename;
不能写成
drop table tablename if exists tablename;
mysql：建立索引Sql
CREATE TABLE tablename (
`ID...
PHP的函数前加上“@”的作用 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...供的错误信息屏蔽的专用符号。比如在一个函数前使用@@mysql_query 不会出现Warning，而原来mysql_query 在遇到错误时会在页面上访提示Warning。@是PHP提供的错误信息屏蔽的专用符号。
比如在一个函数前使用@
@mysql_query 不会出现Warning...
Curses library not found. Please install appropriate package - 更多...
Curses library not found. Please install appropriate packageCentOS安装MySql报错：-- Could NOT find Curses (missing: CURSES_LIBRARY CURSES_INCLUDE_PATH)CMake Error at cmake readli...CentOS安装MySql报错：
-- Could NOT find Curses (missing: CURSES_LIBRARY CURSES_INCLUDE_PATH)
CMake Err...