大约有 7,000 项符合查询结果(耗时:0.0273秒) [XML]
Boost.Asio的简单使用(Timer,Thread,Io_service类) - C/C++ - 清泛网 - 专注C/C++及内核技术
...io的简单使用(Timer,Thread,Io_service类)2. 同步Timer本章介绍asio如何在定时器上进行阻塞等待(blocking wait).实现,我们包含必要的头文件.所有的asio类可以简单的通过include "...目录:
1. 同步Timer
2. 异步Timer
3. 回调函数的参数
4. 成员函...
Overriding id on create in ActiveRecord
...
Perhaps what I experienced only expressed itself with mysql driver.
– jkndrkn
Feb 18 '13 at 19:30
...
大数据:用数据指导APP运营 - 资讯 - 清泛网 - 专注C/C++及内核技术
...感觉在不知不觉中获得了提升,这一点,非常重要。
3 如何获取数据
获取数据的渠道有很多,而方式基本就是自己做和使用外部工具两种方式。
自己做的话,App可以选择“埋点”、log等方式,而Web可以通过log、日志与按钮埋...
Unicode与UTF-8互转(C语言实现) - C/C++ - 清泛网 - 专注C/C++及内核技术
...了符号的二进制代码, 却没有规定这
个二进制代码应该如何存储".
比如, 汉字"严"的unicode是十六进制数4E25, 转换成二进制数足足有15位
(100111000100101), 也就是说这个符号的表示至少需要2个字节. 表示其他更大的符号,
可能需要3...
App Inventor 2 SQLite 拓展:超流行兼容主流SQL语法的迷你本地数据库引擎 ...
...
SQLite 拓展
SQLite
特性
如何使用
背景
属性
事件
方法
常规
事务
数据操作
绑定参数
案例
...
SQL select only rows with max value on a column [duplicate]
...
I know that MySQL allows you to add non aggregate fields to a "grouped by" query, but I find that kinda pointless. Try running this select id, max(rev), rev from YourTable group by id and you see what I mean. Take your time and try to un...
How to test an SQL Update statement before running it?
...What about Transactions? They have the ROLLBACK-Feature.
@see https://dev.mysql.com/doc/refman/5.0/en/commit.html
For example:
START TRANSACTION;
SELECT * FROM nicetable WHERE somthing=1;
UPDATE nicetable SET nicefield='VALUE' WHERE somthing=1;
SELECT * FROM nicetable WHERE somthing=1; #check
CO...
How do I select an entire row which has the largest ID in the table?
...show profiles and it appears our solutions have the same performance using MySQL. For my own knowledge, do you know what DBMS has poorer performance for subselects?
– unutbu
Feb 7 '14 at 20:08
...
How to use JNDI DataSource provided by Tomcat in Spring?
...
auth="Container"
type="javax.sql.DataSource"
driverClassName="com.mysql.jdbc.Driver"
url="jdbc:mysql://localhost:3306/TestDB"
username="pankaj"
password="pankaj123"
maxActive="100"
maxIdle="20"
minIdle="5"
maxWait="10000"/>
back to context.xml de spring add this
...
How to add 'ON DELETE CASCADE' in ALTER TABLE statement
...
Answer for MYSQL USERS:
ALTER TABLE ChildTableName
DROP FOREIGN KEY `fk_table`;
ALTER TABLE ChildTableName
ADD CONSTRAINT `fk_t1_t2_tt`
FOREIGN KEY (`parentTable`)
REFERENCES parentTable (`columnName`)
ON DELETE CASCADE
ON UP...