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How do I change column default value in PostgreSQL?
... name, only that table is altered. If ONLY is not specified, the table and all its descendant tables (if any) are altered" postgresql.org/docs/9.3/static/sql-altertable.html
– Yodan Tauber
Dec 20 '15 at 8:41
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How do you build a Singleton in Dart?
... There's the weird syntax Singleton._internal(); that looks like a method call when it's really a constructor definition. There's the _internal name. And there's the nifty language design point that Dart lets you start out (dart out?) using an ordinary constructor and then, if needed, change it to a...
Precedence and bitmask operations
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You are actually doing this:
var_dump(0b10 & (0b01 == 0));
var_dump(0b10 & (0b01 != 0));
Try:
var_dump((0b10 & 0b01) == 0);
var_dump((0b10 & 0b01) != 0);
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What tools are there for functional programming in C?
...ing in C ( not C++). Obviously, C is a procedural language and doesn't really support functional programming natively.
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Is calculating an MD5 hash less CPU intensive than SHA family functions?
...s with sphlib, a library of hash function implementations in C (and Java). All implementations are from the same author (me) and were made with comparable efforts at optimizations; thus the speed differences can be considered as really intrinsic to the functions.
As a point of comparison, consider ...
Best way to do multi-row insert in Oracle?
...AG_NAME,PAG_ACTIVE)
select 8000,0,'Multi 8000',1 from dual
union all select 8001,0,'Multi 8001',1 from dual
The thing to remember here is to use the from dual statement.
(source)
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How do I create some kind of table of content in GitHub wiki?
...nk is <project URL#<header name>. The <header name> must be all lower case.
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Android SQLite: nullColumnHack parameter in insert/replace methods
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Let's suppose you have a table named foo where all columns either allow NULL values or have defaults.
In some SQL implementations, this would be valid SQL:
INSERT INTO foo;
That's not valid in SQLite. You have to have at least one column specified:
INSERT INTO foo (s...
Max size of an iOS application
...whose MinimumOSVersion is less than 7.0: maximum of 80 MB for the total of all __TEXT sections in the binary.
For apps whose MinimumOSVersion is 7.x through 8.x: maximum of 60 MB per slice for the __TEXT section of each architecture slice in the binary.
For apps whose MinimumOSVersion is 9.0 or grea...
XPath - Selecting elements that equal a value
...the string value of an element as the concatenation (in document order) of all of its text-node descendents.
This explains the "strange results".
"Better" results can be obtained using the expressions below:
//*[text() = 'qwerty']
The above selects every element in the document that has at lea...