大约有 49,000 项符合查询结果（耗时：0.0430秒） [XML]
How do I cast a string to integer and have 0 in case of error in the cast with PostgreSQL?
...hould work:
SELECT CASE WHEN myfield~E'^\\d+$' THEN myfield::integer ELSE 0 END FROM mytable;
share
|
improve this answer
|
follow
|
...
Checking for the correct number of arguments
...
#!/bin/sh
if [ "$#" -ne 1 ] || ! [ -d "$1" ]; then
echo "Usage: $0 DIRECTORY" >&2
exit 1
fi
Translation: If number of arguments is not (numerically) equal to 1 or the first argument is not a directory, output usage to stderr and exit with a failure status code.
More friendly er...
What is the Python equivalent of static variables inside a function?
...
703
A bit reversed, but this should work:
def foo():
foo.counter += 1
print "Counter is %d...
How to pass a single object[] to a params object[]
...
100
A simple typecast will ensure the compiler knows what you mean in this case.
Foo((object)new o...
Creating JS object with Object.create(null)?
...
200
They are not equivalent. {}.constructor.prototype == Object.prototype while Object.create(null)...
how to check redis instance version?
...
310
$ redis-server --version
gives you the version.
...
Capture key press (or keydown) event on DIV element
...
302
(1) Set the tabindex attribute:
<div id="mydiv" tabindex="0" />
(2) Bind to keydown:
...
How to remove the querystring and get only the url?
...
+100
You can use strtok to get string before first occurence of ?
$url = strtok($_SERVER["REQUEST_URI"], '?');
strtok() represents the ...
Multi-gradient shapes
...ze(int width, int height) {
LinearGradient lg = new LinearGradient(0, 0, width, height,
new int[]{Color.GREEN, Color.GREEN, Color.WHITE, Color.WHITE},
new float[]{0,0.5f,.55f,1}, Shader.TileMode.REPEAT);
return lg;
}
};
PaintDrawable p=new PaintDrawable()...
Why is the shovel operator (
...
Proof:
a = 'foo'
a.object_id #=> 2154889340
a << 'bar'
a.object_id #=> 2154889340
a += 'quux'
a.object_id #=> 2154742560
So << alters the original string rather than creating a new one. The reason for this is that in ruby a += b is syntactic short...