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SQL query return data from multiple tables
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Part 1 - Joins and Unions
This answer covers:
Part 1
Joining two or more tables using an inner join (See the wikipedia entry for additional info)
How to use a union query
Left and Right Outer Joins (this stackOverflow answer ...
VM 磁盘空间扩容引起的一些问题 - 更多技术 - 清泛网 - 专注C/C++及内核技术
VM 磁盘空间扩容引起的一些问题TOP如下存储分区如下ESX1下挂载情况如下图ESX2下挂载情况如下图现在有个需求，lun60的空间偏大，缩小为1T，LUN80的空间偏小，扩大为1.5T先...TOP 如下
存储分区如下
ESX1下挂载情况如下图
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How to calculate number of days between two given dates?
If I have two dates (ex. '8/18/2008' and '9/26/2008' ), what is the best way to get the number of days between these two dates?
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How to create the most compact mapping n → isprime(n) up to a limit N?
...at produces a data structure with lowest memory consumption for the range (1, N], where N is a constant.
Just an example of what I am looking for: I could represent every odd number with one bit e.g. for the given range of numbers (1, 10], starts at 3: 1110
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Multiple left-hand assignment with JavaScript
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Actually,
var var1 = 1, var2 = 1, var3 = 1;
is not equivalent to:
var var1 = var2 = var3 = 1;
The difference is in scoping:
function good() {
var var1 = 1, var2 = 1, var3 = 1;
}
function bad() {
var var1 = var2 = var3 = 1;...
Re-ordering columns in pandas dataframe based on column name [duplicate]
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11 Answers
11
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Is there a foreach in MATLAB? If so, how does it behave if the underlying data changes?
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147
MATLAB's FOR loop is static in nature; you cannot modify the loop variable between iterations,...
Ubuntu rails install fails on zlib
I've just moved over to Ubuntu 8.10 as my dev box; it's my first serious foray into Linux as a daily-use OS, and I'm having a hard time getting Rails going. I have followed a number of tutorials which all seem to work fine, but when I try and use gem install or gem update on anything, I get an erro...
Display numbers with ordinal suffix in PHP
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15 Answers
15
Active
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How to calculate the angle between a line and the horizontal axis?
...xtend infinitely and don't start at a particular point).
deltaY = P2_y - P1_y
deltaX = P2_x - P1_x
Then calculate the angle (which runs from the positive X axis at P1 to the positive Y axis at P1).
angleInDegrees = arctan(deltaY / deltaX) * 180 / PI
But arctan may not be ideal, because dividin...