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Check if a table exists in Rails
...? 'kittens'
In Rails 2, 3 & 4 the API is about tables.
# Listing of all tables and views
ActiveRecord::Base.connection.tables
# Checks for existence of kittens table/view (Kitten model)
ActiveRecord::Base.connection.table_exists? 'kittens'
Getting the status of migrations:
# Tells you all...
What's the fuss about Haskell? [closed]
...eems to love that language. Being good at Haskell seems somewhat like the hallmark of a genius programmer.
17 Answers
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Best way to create an empty object in JSON with PHP?
To create an empty JSON object I do usually use:
7 Answers
7
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Easy way to list node modules I have npm linked?
...ts (e.g. ls -l node_modules | grep ^l)? They're normal symlinks.
If you really need to find all symlinks, you could try something like find / -type d -name "node_modules" 2>/dev/null | xargs -I{} find {} -type l -maxdepth 1 | xargs ls -l.
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Why are C# 3.0 object initializer constructor parentheses optional?
It seems that the C# 3.0 object initializer syntax allows one to exclude the open/close pair of parentheses in the constructor when there is a parameterless constructor existing. Example:
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Why is Git better than Subversion?
...urceSafe , I just love Subversion. Combined with TortoiseSVN , I can't really imagine how it could be any better.
30 An...
Is there an SQLite equivalent to MySQL's DESCRIBE [table]?
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You can use ".schema" without a table and it'll show you all of them.
– Dan Benamy
Nov 30 '12 at 6:16
46
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How to create a .NET DateTime from ISO 8601 format
...standard, they seem to be able to parse only a limited subset of it. Especially it is a problem if the string contains time zone specification. (Neither it does for basic ISO8601 formats, or reduced precision formats - however this is not exactly your case.) That is why I make use of custom format s...
Which characters make a URL invalid?
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@techiferous, Yeah, I forgot to allow "%" escaped characters. It should've looked more like: /^([!#$&-;=?-[]_a-z~]|%[0-9a-fA-F]{2})+$/ Was there anything else that you found it should've been accepting? (Just to be clear, that regex only checks ...
Is the order guaranteed for the return of keys and values from a LinkedHashMap object?
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The Map interface provides three
collection views, which allow a map's contents to be viewed as a set
of keys, collection of values, or set
of key-value mappings. The order of
a map is defined as the order in which
the iterators on the map's collection
views return their ...