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一个故事告诉你比特币的原理及运作机制 - 创意 - 清泛网 - 专注C/C++及内核技术
...这样以物易物实在太不方便了，于是村子全员开会，讨论如何解决这个问题。有人提议，以便于分割且稀有的东西，例如黄金，作为一般等价物，把其它物品和黄金的对应关系编成一张表格，例如一克黄金对应一只羊，一克黄金...
MySQL Error 1215: Cannot add foreign key constraint
...the 4th point was my problem. It's kind of nasty - but I'm very very happy mysql did crash for that
– Sebas
Jun 16 '16 at 15:21
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Get all table names of a particular database by SQL query?
...working on application which can deal with multiple database servers like "MySQL" and "MS SQL Server".
19 Answers
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将Linux代码移植到Windows的简单方法 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
...一项困难的工作。本文将以一个实际的例子（Tar）来说明如何把Linux代码移植到Windows平台上。移植过程将尽量少修改代码,以便代码的运行逻辑不会发生任何变动。保留绝大部分软件主要功能。
二．准备工作
Tar是Linux平台下面...
Return 0 if field is null in MySQL
In MySQL, is there a way to set the "total" fields to zero if they are NULL?
5 Answers
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How to see indexes for a database or table in MySQL?
...wered Mar 6 '11 at 21:05
RolandoMySQLDBARolandoMySQLDBA
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MySQL - UPDATE multiple rows with different values in one query
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Excuse my english sir, when i try to make an update mysql give me the error: # 1062 - Duplicate entry 'XXX' for key 'PRIMARY'. That does when I try to update a record with the same value it already had, is there any way to skip the update if the current value is the same as be...
How to copy a row and insert in same table with a autoincrement field in MySQL?
In MySQL I am trying to copy a row with an autoincrement column ID=1 and insert the data into same table as a new row with column ID=2 .
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Calculate difference between two datetimes in MySQL
I am storing the last login time in MySQL in, datetime -type filed. When users logs in, I want to get the difference between the last login time and the current time (which I get using NOW() ).
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How do I get SUM function in MySQL to return '0' if no values are found?
Say I have a simple function in MySQL:
4 Answers
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