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difference between primary key and unique key
I'm using mysql database. I have a confusion between primary key and unique key.
15 Answers
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Failed to locate the winutils binary in the hadoop binary path
.... I didn't find winutils exe file in hadoop bin folder. I tried below commands
15 Answers
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What are the differences between ipython and bpython?
What does ipython have that bpython lacks and vice versa? How do the two differ?
2 Answers
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django import error - No module named core.management
... I see plenty of these errors around. I have tried everything I know to do and have yet to figure this out.
29 Answers
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How to test that no exception is thrown?
...I have noticed this question garners interest from time to time so I'll expand a little.
Background to unit testing
When you're unit testing it's important to define to yourself what you consider a unit of work. Basically: an extraction of your codebase that may or may not include multiple methods...
How can I detect if a selector returns null?
...See my answer porting Rails' presence method.
– Marc-André Lafortune
Feb 26 '13 at 22:22
5
If yo...
Vim: insert the same characters across multiple lines
... busy during that time—it’s just waiting for you to press another key, and eventually times out. Two experiments for you: first, try pressing escape and then immediately pressing another key, like j or ^L. You should see that Vim wasn’t busy after all; it was just waiting. Second, try changing...
How to use gradle zip in local system without downloading when using gradle-wrapper
...ip in gradle/wrapper/.
Then, ./gradlew build downloaded local copy of zip and built the project.
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How to check whether an object is a date?
...rator, i.e. But it will return true for invalid dates too, e.g. new Date('random_string') is also instance of Date
date instanceof Date
This will fail if objects are passed across frame boundaries.
A work-around for this is to check the object's class via
Object.prototype.toString.call(date) ==...
What database does Google use?
... designed to scale to a very
large size: petabytes of data across
thousands of commodity servers.
Many projects at Google store data in
Bigtable, including web indexing,
Google Earth, and Google Finance.
These applications place very
different demands on Bigtable, both in
terms of...