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MySQL, better to insert NULL or empty string?
...re differences:
A LENGTH of NULL is NULL, a LENGTH of an empty string is 0.
NULLs are sorted before the empty strings.
COUNT(message) will count empty strings but not NULLs
You can search for an empty string using a bound variable but not for a NULL. This query:
SELECT *
FROM mytable
WHERE ...
I forgot the password I entered during postgres installation
...ld
you should change
local all all trust
to
host all all 127.0.0.1/32 trust
you can now connect as any user. Connect as the superuser postgres (note, the superuser name may be different in your installation. In some systems it is called pgsql, for example.)
psql -U postgres
or
psql...
npm check and update package if needed
... if there is a newer version in the NPM registry.
For example, say xml2js 0.2.6 (located in node_modules in the current project) is outdated because a newer version exists (0.2.7). You would see:
xml2js@0.2.7 node_modules/xml2js current=0.2.6
To update all dependencies, if you are confident this...
Converting double to string
... |
edited Mar 31 '16 at 10:20
Sнаđошƒаӽ
11.6k1111 gold badges6060 silver badges8383 bronze badges
...
Where is array's length property defined?
...t find it in any .class file), they're a part of the language itself.
10.7. Array Members
The members of an array type are all of the following:
The public final field length, which contains the number of components of the array. length may be positive or zero.
The public method c...
Create an array with same element repeated multiple times
...
You can do it like this:
function fillArray(value, len) {
if (len == 0) return [];
var a = [value];
while (a.length * 2 <= len) a = a.concat(a);
if (a.length < len) a = a.concat(a.slice(0, len - a.length));
return a;
}
It doubles the array in each iteration, so it can create a ...
Why does this iterative list-growing code give IndexError: list assignment index out of range?
...
j is an empty list, but you're attempting to write to element [0] in the first iteration, which doesn't exist yet.
Try the following instead, to add a new element to the end of the list:
for l in i:
j.append(l)
Of course, you'd never do this in practice if all you wanted to do wa...
javascript i++ vs ++i [duplicate]
...
207
The difference between i++ and ++i is the value of the expression.
The value i++ is the value ...
How to read a CSV file into a .NET Datatable
...
answered Jun 26 '09 at 16:57
Jay RiggsJay Riggs
50.1k99 gold badges127127 silver badges142142 bronze badges
...
Recursive sub folder search and return files in a list python
...mport glob
result = [y for x in os.walk(PATH) for y in glob(os.path.join(x[0], '*.txt'))]
Also a generator version
from itertools import chain
result = (chain.from_iterable(glob(os.path.join(x[0], '*.txt')) for x in os.walk('.')))
Edit2 for Python 3.4+
from pathlib import Path
result = list(Pa...