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What's the best practice for primary keys in tables?
When designing tables, I've developed a habit of having one column that is unique and that I make the primary key. This is achieved in three ways depending on requirements:
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Should each and every table have a primary key?
...e link. Thus you ensure that you don't have two or more records describing one link.
Besides the logical consistency issues, most RDBMS engines will benefit from including these fields in a unique index.
And since any primary key involves creating a unique index, you should declare it and get both...
JPA EntityManager: Why use persist() over merge()?
EntityManager.merge() can insert new objects and update existing ones.
15 Answers
15
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What exactly does git's “rebase --preserve-merges” do (and why?)
...ase, git with --preserve-merges first identifies a list of commits made in one part of the commit graph, and then replays those commits on top of another part. The differences with --preserve-merges concern which commits are selected for replay and how that replaying works for merge commits.
To be ...
Entity Framework vs LINQ to SQL
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This answer is obsolete. Now Linq to SQL supports one2many mapping
– George Lanetz
Dec 29 '15 at 13:18
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What is “entropy and information gain”?
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I assume entropy was mentioned in the context of building decision trees.
To illustrate, imagine the task of learning to classify first-names into male/female groups. That is given a list of names each labeled with either m or f, we want to learn a m...
Java: Multiple class declarations in one file
...define multiple top level classes in a single file, providing that at most one of these is public (see JLS §7.6 ). See below for example.
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What is the best (and safest) way to merge a Git branch into master?
...merge test
git push origin master
If I have a local branch from a remote one, I don't feel comfortable with merging other branches than this one with the remote. Also I would not push my changes, until I'm happy with what I want to push and also I wouldn't push things at all, that are only for me ...
Catching multiple exception types in one catch block
...y to obtain the following functionality, to catch AError and BError in one block:
11 Answers
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Is there any reason for using WebGL instead of 2D Canvas for 2D games/apps?
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Looking at this question from another side:
how does a developer choose one technology over another?
integrates better in their already built system
is easier to use
is faster
has more capabilities or better suits their needs
cost
more platfrom-independant
So I'll discuss the differences betw...