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What can you use Python generator functions for?
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Real World Example
Let's say you have 100 million domains in your MySQL table, and you would like to update Alexa rank for each domain.
First thing you need is to select your domain names from the database.
Let's say your table name is domains and column name is domain.
If you use SELECT...
AJAX POST and Plus Sign ( + ) — How to Encode?
... and the plus sign (+) when i to try to save javascript "code examples" to mysql:
my solution (not the better way, but it works):
javascript:
function replaceAll( text, busca, reemplaza ){
while (text.toString().indexOf(busca) != -1)
text = text.toString().replace(busca,reemplaza);return text...
When and why are database joins expensive?
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MySQL, Oracle, SQL Server, Sybase, postgreSQL,etc. care not the order of joins. I've worked with DB2 and it also, to my knowledge, doesn't care what order you put them in. This is not helpful advice in the general case
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How to update column with null value
I am using mysql and need to update a column with a null value. I have tried this many different ways and the best I have gotten is an empty string.
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MySQL Error 1093 - Can't specify target table for update in FROM clause
...handle the OP's exact query, please see other answers to this question
In MySQL, you can't modify the same table which you use in the SELECT part.
This behaviour is documented at:
http://dev.mysql.com/doc/refman/5.6/en/update.html
Maybe you can just join the table to itself
If the logic is simple...
#1071 - Specified key was too long; max key length is 767 bytes
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767 bytes is the stated prefix limitation for InnoDB tables in MySQL version 5.6 (and prior versions). It's 1,000 bytes long for MyISAM tables. In MySQL version 5.7 and upwards this limit has been increased to 3072 bytes.
You also have to be aware that if you set an index on a big char ...
MySQL - Make an existing Field Unique
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ALTER IGNORE TABLE mytbl ADD UNIQUE (columnName);
For MySQL 5.7.4 or later:
ALTER TABLE mytbl ADD UNIQUE (columnName);
As of MySQL 5.7.4, the IGNORE clause for ALTER TABLE is removed and
its use produces an error.
So, make sure to remove duplicate entries first as IGNO...
Alter MySQL table to add comments on columns
I have been checking the MySQL Documentation for ALTER TABLE and it does not seem to include a way to add or modify a comment to a column. How can I do this?
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PDOException “could not find driver”
I have just installed Debian Lenny with Apache, MySQL, and PHP and I am receiving a PDOException could not find driver .
3...
使用Activity启动器组件 · App Inventor 2 中文网
...频
选择联系人
启动其他外部应用程序
了解如何设置 ActivityStarter 属性
在应用程序之间传递值
将活动启动器与两个 App Inventor 应用程序一起使用
该应用程序在设备上可用吗？
附录：为设计...