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How to store arrays in MySQL?
I have two tables in MySQL. Table Person has the following columns:
7 Answers
7
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Random record in ActiveRecord
...selected entries. (Be aware that it's RANDOM() in PostgreSQL and RAND() in MySQL ... not as portable as you may want it to be.)
– Florian Pilz
Jun 16 '11 at 13:17
3
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Which is fastest? SELECT SQL_CALC_FOUND_ROWS FROM `table`, or SELECT COUNT(*)
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It depends. See the MySQL Performance Blog post on this subject: To SQL_CALC_FOUND_ROWS or not to SQL_CALC_FOUND_ROWS?
Just a quick summary: Peter says that it depends on your indexes and other factors. Many of the comments to the post seem to...
How to do a batch insert in MySQL
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From the MySQL manual
INSERT statements that use VALUES
syntax can insert multiple rows. To do
this, include multiple lists of column
values, each enclosed within
parentheses and separated by commas.
Example:
INSERT IN...
How do you list all triggers in a MySQL database?
What is the command to list all triggers in a MySQL database?
4 Answers
4
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App Inventor 2开发计步器与定位器 - App Inventor 2 中文网 - 清泛IT论坛，有思想、有深度
...编写“健身宝”手机应用程序
3.问题：
（1）如何获取走路步数、距离？
（2）如何计算走路时间？
（3）如何获得当前位置？
（4）如何存储信息？
4.规划：
（1）利用pedometer（计步器）组件...
MySQL: Invalid use of group function
I am using MySQL. Here is my schema:
2 Answers
2
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How to change the default charset of a MySQL table?
There is a MySQL table which has this definition taken from SQLYog Enterprise :
5 Answers
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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...
How to select records from last 24 hours using SQL?
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In MySQL:
SELECT *
FROM mytable
WHERE record_date >= NOW() - INTERVAL 1 DAY
In SQL Server:
SELECT *
FROM mytable
WHERE record_date >= DATEADD(day, -1, GETDATE())
In Oracle:
SELECT *
FROM mytable
WHER...