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How to design a product table for many kinds of product where each product has many parameters
...the type hierarchy you describe:
Single Table Inheritance: one table for all Product types, with enough columns to store all attributes of all types. This means a lot of columns, most of which are NULL on any given row.
Class Table Inheritance: one table for Products, storing attributes common to...
How do I hide .class files from the Open Resource dialog in Eclipse?
I won't want to have edit any working sets. I just want a way to, across all workspaces and projects, prevent .class files from ever showing in the Open Resource Dialog. Is there a way to do this?
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What's the difference between struct and class in .NET?
...or a struct, that means that the variable contains the entire struct, with all its fields.
A variable containing a reference type contains a pointer, or a reference to somewhere else in memory where the actual value resides.
This has one benefit, to begin with:
value types always contains a valu...
How do you stash an untracked file?
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To stash your working directory including untracked files (especially those that are in the .gitignore) then you probably want to use this cmd:
git stash --include-untracked
More details:
Update 17 May 2018:
New versions of git now have git stash --all which stashes all files, includin...
How do I get the size of a java.sql.ResultSet?
...ng about them to others, regardless of whether they are static or not. Actually creating an instance of the object and calling the method is implied.
– laz
Oct 10 '08 at 18:23
51
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RegEx for matching UK Postcodes
...that will validate a full complex UK postcode only within an input string. All of the uncommon postcode forms must be covered as well as the usual. For instance:
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django models selecting single field
I have a table/models called Employees and I would like to get all rows of a single field as a queryset.
5 Answers
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Can't install RMagick 2.13.1. Can't find MagickWand.h.
When I try do install rmagick I get the following error message:
32 Answers
32
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Test if a vector contains a given element
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what about getting all appearances, not just the first one?
– StatsSorceress
Mar 15 '18 at 0:54
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How to get multiple counts with one SQL query?
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You can use a CASE statement with an aggregate function. This is basically the same thing as a PIVOT function in some RDBMS:
SELECT distributor_id,
count(*) AS total,
sum(case when level = 'exec' then 1 else 0 end) AS ExecCount,
sum(case when level = 'personal' then 1 else 0 end) A...