大约有 42,000 项符合查询结果（耗时：0.0150秒） [XML]
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.
...
Optimal way to concatenate/aggregate strings
...com/en-us/sql/t-sql/functions/string-agg-transact-sql
GROUP_CONCAT() in MySQL
http://dev.mysql.com/doc/refman/5.7/en/group-by-functions.html#function_group-concat
(Thanks to @Brianjorden and @milanio for Azure update)
Example Code:
select Id
, STRING_AGG(Name, ', ') Names
from Demo
group by I...
App Inventor 2 人脸识别App开发 - 第三方API接入的通用方法 · App Inventor 2 中文网
...建一个应用以获得API调用时必要的api_key及api_secret。
如何理解api_key及api_secret：可以类比为 API Key是用户ID（用于标识用户），Secret Key是密码（用于鉴权）。“你需要两个不同的密钥，一个告诉他们你是谁，另一个证明你就是...
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...
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.
...
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.
...
实战做项目如何选择开源许可协议（一）-了解协议 - 开源 & Github - 清泛网...
实战做项目如何选择开源许可协议（一）-了解协议opensource_permission目前国内开源项目正在逐渐升温，中国也开始有不少优秀的开源项目突显出来。在大家摩拳擦掌准备加入开源大军时，也要知道这个圈子里的规则。...目前国内...
How to test which port MySQL is running on and whether it can be connected to?
I have installed MySQL and even logged in there as a user.
13 Answers
13
...