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Is it possible to roll back CREATE TABLE and ALTER TABLE statements in major SQL databases?
...cle Database 11g Release 2 and above - by default, no, but an alternative called edition-based redefinition exists
Older versions of Oracle - no; DDL causes an implicit commit
SQL Server - yes
Sybase Adaptive Server - yes
DB2 - yes
Informix - yes
Firebird (Interbase) - yes
SQLite also appears to h...
Changing the maximum length of a varchar column?
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You need
ALTER TABLE YourTable ALTER COLUMN YourColumn <<new_datatype>> [NULL | NOT NULL]
But remember to specify NOT NULL explicitly if desired.
ALTER TABLE YourTable ALTER COLUMN YourColumn VARCHAR (500) NOT NULL;
If you leave it unspecified as below...
ALTER TABLE Your...
What are the differences between SML and OCaml? [closed]
...fe but restricted equality types in SML), non-generalized type variables ('_a in OCaml), printf, interpretation of file names as module names in OCaml, far more currying in OCaml's stdlib. You wrote interface twice when you meant something else (implementation?) the second time.
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How to explain callbacks in plain english? How are they different from calling one function from ano
How to explain callbacks in plain English? How are they different from calling one function from another function taking some context from the calling function? How can their power be explained to a novice programmer?
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Get the date (a day before current time) in Bash
... a one-liner, so cut and paste should work -- no line endings assumed. date_days_past () { days_past=${1:-0}; if ! date -v-${days_past}d +%Y%m%d 2>/dev/null; then date --date="-${days_past} day" +%Y%m%d; fi }
– Noah Spurrier
May 16 '16 at 21:29
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How do I append text to a file?
...ther source.
Or else entered at the keyboard, doesn't matter.
^D
Essentially, you can dump any text you want into the file. CTRL-D sends an end-of-file signal, which terminates input and returns you to the shell.
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Citing the author of a blockquote using Markdown syntax
...ld like to have the quote followed by a citation beneath it, but right now all it does is blockquote the whole line. How does one do this in markdown syntax?
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HintPath vs ReferencePath in Visual Studio
...mit to a convention where dependency DLLs are in a "releases" svn repo and all projects point to a particular release. Since different developers have different folder structures, relative references won't work, so we came up with a scheme to use an environment variable pointing to the particular de...
Git diff output to file preserve coloring
...ion and open it in Notepad++ or Vim or SublimeText.
git diff > 20150203_someChanges.diff
Thanks @Monsingor
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Simple way to create matrix of random numbers
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You can drop the range(len()):
weights_h = [[random.random() for e in inputs[0]] for e in range(hiden_neurons)]
But really, you should probably use numpy.
In [9]: numpy.random.random((3, 3))
Out[9]:
array([[ 0.37052381, 0.03463207, 0.10669077],
[ 0.05...