大约有 42,000 项符合查询结果（耗时：0.0250秒） [XML]
Is there a REAL performance difference between INT and VARCHAR primary keys?
...e performance difference between using INT vs. VARCHAR as a primary key in MySQL? I'd like to use VARCHAR as the primary key for reference lists (think US States, Country Codes) and a coworker won't budge on the INT AUTO_INCREMENT as a primary key for all tables.
...
PDOException SQLSTATE[HY000] [2002] No such file or directory
...
The error message indicates that a MySQL connection via socket is tried (which is not supported).
In the context of Laravel (artisan), you probably want to use a different / the correct environment. Eg: php artisan migrate --env=production (or whatever enviro...
How to shrink/purge ibdata1 file in MySQL
I am using MySQL in localhost as a "query tool" for performing statistics in R, that is, everytime I run a R script, I create a new database (A), create a new table (B), import the data into B, submit a query to get what I need, and then I drop B and drop A.
...
MySQL show status - active or total connections?
...
Connections
The number of connection attempts (successful or not) to the MySQL server.
You can see the number of active connections either through the Threads_connected status variable:
Threads_connected
The number of currently open connections.
mysql> show status where `variable_name` = 'Th...
App Inventor 2 低功耗蓝牙(BLE) 硬件接入、数据通信及IO控制 - App Invent...
...本文主要介绍一款较为通用、价格低廉的BLE设备从零开始如何利用App Inventor 2开发一款自己专属的手机蓝牙App应用。BLE与经典蓝牙的区别可参考：《低功耗蓝牙(BLE) 和 经典蓝牙(SPP) 的区别》。本文主要通过一款常见的BLE硬件接入...
mysql blob大小配置介绍 - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
...理器（如数据库管理器）不去理会文件是什么，而是关心如何去处理它。但也有专家强调，这种处理大数据对象的方法是把双刃剑，它有可能引发一些问题，如存储的二进制文件过大，会使数据库的性能下降。在数据库中存放体...
How can I import a database with MySQL from terminal?
How can I import a database with mysql from terminal?
18 Answers
18
...
Restoring MySQL database from physical files
Is it possible to restore a MySQL database from the physical database files. I have a directory that has the following file types:
...
Can't connect to MySQL server error 111 [closed]
I installed mysql server on linux box IP = 192.168.1.100 but when i try to connect to this IP it alway error(111). but use localhost and 127.0.0.1 is OK.
...
SQL中使用update inner join和delete inner join；Oracle delete join替代...
...here and table1.khid=table2.khid and FWDWID=8);
Oracle的delete与join如何使用
delete from A where sid in
(select a.sid from A a inner join B b on a.num2 = b.num1
where b.num2 not between '10'and '10000') 这段sql如何优化，不使用in？
1. 用exists 来替代 in
delete fr...