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How do I add a foreign key to an existing SQLite table?
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SQLite doesn't support the ADD CONSTRAINT variant of the ALTER TABLE command (sqlite.org: SQL Features That SQLite Does Not Implement).
Therefore, the only way to add a foreign key in sqlite 3.6.1 is during CREATE TABLE as follows:
CREATE TABLE child (
id INTEGER PRIMARY KEY,
...
How to share Eclipse configuration over different workspaces
...es. (like at home, laptop, in office, etc.). How could I share the Eclipse and project configuration pragmatically between multiple computers? Should I version control them, or is there any easier way to do this?
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SQL Joins Vs SQL Subqueries (Performance)?
...PECT the first query to be quicker, mainly because you have an equivalence and an explicit JOIN. In my experience IN is a very slow operator, since SQL normally evaluates it as a series of WHERE clauses separated by "OR" (WHERE x=Y OR x=Z OR...).
As with ALL THINGS SQL though, your mileage may va...
Making heatmap from pandas DataFrame
I have a dataframe generated from Python's Pandas package. How can I generate heatmap using DataFrame from pandas package.
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Understanding offsetWidth, clientWidth, scrollWidth and -Height, respectively
... on StackOverflow regarding offsetWidth / clientWidth / scrollWidth (and -Height , respectively), but none give comprehensive explanation of what those values are.
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What does the “__block” keyword mean?
...eated in a special way when it is used inside a block. Normally, variables and their contents that are also used in blocks are copied, thus any modification done to these variables don't show outside the block. When they are marked with __block, the modifications done inside the block are also visib...
Why are we not to throw these exceptions?
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Exception is the base type for all exceptions, and as such terribly unspecific. You shouldn’t ever throw this exception because it simply does not contain any useful information. Calling code catching for exceptions couldn’t disambiguate the intentionally thrown excep...
.NET WPF Remember window size between sessions
...ifferent type or structure will be needed.
Initialise the first two to 0 and the second two to the default size of your application, and the last one to false.
Create a Window_OnSourceInitialized event handler and add the following:
this.Top = Properties.Settings.Default.Top;
this.Left = Propert...
How to shrink the .git folder
...gressive --prune, which will perform garbage collection in your repository and prune old objects. do you have a lot of binary files (archives, images, executables) which change often? those usually lead to huge .git folders (remember, git stores snapshots for each revision and binary files compress ...
Git rebase --continue complains even when all merge conflicts have been resolved
...urrently being applied to the branch you rebase on. After fixing the patch and doing
git add your/conflicted/file
git status
you will get a (usually green) line showing the modified file
modified: your/conflicted/file
git rebase --continue will work fine in this situation.
Sometimes, h...