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What is the difference between UTF-8 and ISO-8859-1?
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UTF-8 is a multibyte encoding that can represent any Unicode character. ISO 8859-1 is a single-b...
Creating Multifield Indexes in Mongoose / MongoDB
...For your case it would be something like:
mySchema.index({field1: 1, field2: 1}, {unique: true});
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Can we set a Git default to fetch all tags during a remote pull?
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answered May 21 '13 at 19:50
joshtklingjoshtkling
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Hash collision in git
...aracter times 40... 160 bits. Now we know 10 bits is approximately 1000 (1024 to be exact) meaning that there are 1 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 different SHA-1 hashes... 1048.
What is this equivalent of? Well the Moon is made up of about 1047 atoms. So if we have ...
How to handle initializing and rendering subviews in Backbone.js?
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This is a great question. Backbone is great because of the lack of assumptions it makes, but i...
Create unique constraint with null columns
..., menu_id, recipe_id)
WHERE menu_id IS NOT NULL;
CREATE UNIQUE INDEX favo_2col_uni_idx ON favorites (user_id, recipe_id)
WHERE menu_id IS NULL;
This way, there can only be one combination of (user_id, recipe_id) where menu_id IS NULL, effectively implementing the desired constraint.
Possible dra...
Convert data.frame columns from factors to characters
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edited May 23 '17 at 12:18
Community♦
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answered May 17 '10 at 17:21
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How to change a nullable column to not nullable in a Rails migration?
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208
If you do it in a migration then you could probably do it like this:
# Make sure no null valu...
Are nested try/except blocks in python a good programming practice?
...") from None
PS. has_key() has been deprecated for a long time in Python 2. Use item in self.dict instead.
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