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How to delete or add column in SQLITE?
...upports a limited subset of ALTER TABLE. The ALTER TABLE command in SQLite allows the user to rename a table or to add a new column to an existing table. It is not possible to rename a column, remove a column, or add or remove constraints from a table.
You can:
create new table as the one you ar...
Best way to test for a variable's existence in PHP; isset() is clearly broken
... This looks a bit ugly to me, but in the case where you're actually checking an array element, it makes much more sense: isset($foo[$bar]) becomes array_key_exists($bar, $foo)
– Arild
Aug 25 '14 at 14:12
...
What does T&& (double ampersand) mean in C++11?
...e in the draft C++11 standard, but are not true for the final one! Specifically, it says at various points that rvalue references can bind to lvalues, which was once true, but was changed.(e.g. int x; int &&rrx = x; no longer compiles in GCC) – drewbarbs Jul 13 '14 at 16:12
The biggest d...
What exactly is a reentrant function?
...
1. How is safely defined?
Semantically. In this case, this is not a hard-defined term. It just mean "You can do that, without risk".
2. If a program can be safely executed concurrently, does it always mean that it is reentrant?
No.
For example, let's have ...
How to paste yanked text into the Vim command line
...you know how to use them you cannot live without them.
Registers are basically storage locations for strings. Vim has many registers that work in different ways:
0 (yank register: when you use y in normal mode, without specifying a register, yanked text goes there and also to the default register...
What are the differences between double-dot “..” and triple-dot “…” in Git diff commit ranges?
...ion of the difference between .. (dot-dot) and ... (dot-dot-dot) is essentially the same as in manojlds's answer.
The command git diff typically¹ only shows you the difference between the states of the tree between exactly two points in the commit graph. The .. and ... notations in git diff have t...
Is arr.__len__() the preferred way to get the length of an array in Python?
...ples:
my_tuple = (1,2,3,4,5)
len(my_tuple)
# 5
And strings, which are really just arrays of characters:
my_string = 'hello world'
len(my_string)
# 11
It was intentionally done this way so that lists, tuples and other container types or iterables didn't all need to explicitly implement a public...
How to encode the filename parameter of Content-Disposition header in HTTP?
...
All in all, this is nothing but a link-only answer with 74 upvotes.
– Antti Haapala
Sep 11 '16 at 21:33
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Writing Unicode text to a text file?
...a out of a Google doc, processing it, and writing it to a file (that eventually I will paste into a Wordpress page).
8 Answ...
How to set child process' environment variable in Makefile
...
I have GNU make 3.81, and all: <\n\t>export PROJ_ROOT=$(CURDIR)<\n\t>echo $(PROJ_ROOT)<\n> outputs the correct expansion for the first row, but only echo for the second one. PROJ_ROOT is not set after running make. Spaces around = gi...