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MySQL Cannot Add Foreign Key Constraint
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Best Answer Ever, After trying almost everything, it turned out that I have to explicitly add unique to the reference table column even though it's a Primary Key!!
– Yahya
Nov 14 '17 at ...
Check if a Postgres JSON array contains a string
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This is useful when the item is null as well
– Lucio
Nov 8 '17 at 20:33
2
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How to use bootstrap-theme.css with bootstrap 3?
...tstrap source. The affected elements are (as of Bootstrap v3.2.0):
List items
Buttons
Images
Dropdowns
Navbars
Alerts
Progress bars
List Groups
Panels
Wells
The theme.less file depends on:
@import "variables.less";
@import "mixins.less";
The code uses colors defined in variables.less in seve...
What is “Service Include” in a csproj file for?
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I had a similar case, where this was added:
<ItemGroup>
<Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
</ItemGroup>
This inclusion turns out to be generated on purpose by VS2013 if you create an NUnit test project, but forget to tag it as...
Beginner's guide to ElasticSearch [closed]
...tps://www.elastic.co/blog/author/zachary-tong
To be perfectly honest, the best source of beginner knowledge is now Elasticsearch - The Definitive Guide written by myself and Clinton Gormley.
It assumes zero search engine knowledge and explains information retrieval first principals in context of...
UIView Hide/Show with animation
...Previous Solution
Michail's solution will work, but it's not actually the best approach.
The problem with alpha fading is that sometimes the different overlapping view layers look weird as they fade out. There are some other alternatives using Core Animation. First include the QuartzCore framework...
select and update database record with a single queryset
...e query, compared to approach 2 which makes 'n+1' database queries. (For n items in the query set)
Fist approach makes one db query ie UPDATE, the second one makes two: SELECT and then UPDATE.
The tradeoff is that, suppose you have any triggers, like updating updated_on or any such related fields, i...
How to implement one-to-one, one-to-many and many-to-many relationships while designing tables?
... Status varchar2(8),
StampDate date
);
CREATE TABLE Inventory(
Item varchar2(6) PRIMARY KEY,
Description varchar2(30),
CurrentQuantity number(4) NOT NULL,
VendorNumber number(2) REFERENCES Vendor(VendorNumber),
ReorderQuantity number(3) NOT NULL
);
Many-to-many (M:M)
A...
Should import statements always be at the top of a module?
...tion if your profiling shows that would help (you did profile to see where best to improve performance, right??)
The best reasons I've seen to perform lazy imports are:
Optional library support. If your code has multiple paths that use different libraries, don't break if an optional library is ...
Ignoring an already checked-in directory's contents?
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TL;DR to clean up your git repository and make sure ALL your ignored items are indeed ignored:
git rm -r --cached .
git add .
git commit -m "Clean up ignored files"
Note: you don't need to specify a directory, this way your are cleaning the entire remote repo.
To go further read this
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