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How to list the tables in a SQLite database file that was opened with ATTACH?
....schema tablename
Print the entire table:
SELECT * FROM tablename;
List all of the available SQLite prompt commands:
.help
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PostgreSQL: insert from another table
...
Just supply literal values in the SELECT:
INSERT INTO TABLE1 (id, col_1, col_2, col_3)
SELECT id, 'data1', 'data2', 'data3'
FROM TABLE2
WHERE col_a = 'something';
A select list can contain any value expression:
But the expressions in the select list do not have to reference any columns i...
PHP and MySQL - how to avoid password in source code? [duplicate]
I have a small PHP application storing data in a MySQL database. Currently username / password are hard-coded in the PHP code. A situation I do not really like, for example, since the code is also available in a repository.
...
Java string to date conversion
...tern seems valid.
Here's an extract of relevance from the javadoc, listing all available format patterns:
Letter Date or Time Component Presentation Examples
------ ---------------------- ------------------ -------------------------------------
G Era designator Text ...
How do I remove all non alphanumeric characters from a string except dash?
How do I remove all non alphanumeric characters from a string except dash and space characters?
13 Answers
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Scatterplot with too many points
...;- data.frame(x = rnorm(5000),y=rnorm(5000))
ggplot(df,aes(x=x,y=y)) + geom_point(alpha = 0.3)
Another convenient way to deal with this is (and probably more appropriate for the number of points you have) is hexagonal binning:
ggplot(df,aes(x=x,y=y)) + stat_binhex()
And there is also regula...
@ variables in Ruby on Rails
...cope (current block)
@title is an instance variable - and is available to all methods within the class.
You can read more here:
http://strugglingwithruby.blogspot.dk/2010/03/variables.html
In Ruby on Rails - declaring your variables in your controller as instance variables (@title) makes them ava...
What does “coalgebra” mean in the context of programming?
...coalgebras" several times in functional programming and PLT circles, especially when the discussion is about objects, comonads, lenses, and such. Googling this term gives pages that give mathematical description of these structures which is pretty much incomprehensible to me. Can anyone please expla...
Installing libv8 gem on OS X 10.9+
...se the --with-system-v8 option.
Using RubyGems:
gem install libv8 [-v YOUR_VERSION] -- --with-system-v8
Using Bundler (in your Gemfile):
bundle config build.libv8 --with-system-v8
Please note that if you intend to run your own V8, you must install both V8 and its headers (found in libv8-dev for ...
What are best practices for multi-language database design? [closed]
...e language.
In some cases we add a DefaultLanguage field, so that we can fall-back to that language if no localized data is available for a specified language.
Example:
Table "Product":
----------------
ID : int
<any other language-neutral fields>
Table "ProductTranslation...