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Fastest check if row exists in PostgreSQL
...f a single row from the batch exists in the table because then I know they all were inserted.
8 Answers
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How to print matched regex pattern using awk?
...search for pattern using //, then print out the line, which by default is called a record, denoted by $0. At least read up the documentation.
If you only want to get print out the matched word.
awk '{for(i=1;i<=NF;i++){ if($i=="yyy"){print $i} } }' file
...
Objective-C: Property / instance variable in category
...e, it wouldn't work.
Fortunately, the Objective-C runtime has this thing called Associated Objects that can do exactly what you're wanting:
#import <objc/runtime.h>
static void *MyClassResultKey;
@implementation MyClass
- (NSString *)test {
NSString *result = objc_getAssociatedObject(sel...
社交应用组件 · App Inventor 2 中文网
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快速上手：把会议加入日历
when 按钮_加入.Click() {
日历日程1.AddEvent("组会", 计时器1.MakeInstantFromParts(2026, 10, 8, 9, 0, 0), 计时器1.MakeInstantFromParts(2026, 10, 8, 10, 0, 0), "305 室", "带电脑", 15)
}
when 日历日程1.EventAdded(...
How to validate GUID is a GUID
...
When I'm just testing a string to see if it is a GUID, I don't really want to create a Guid object that I don't need. So...
public static class GuidEx
{
public static bool IsGuid(string value)
{
Guid x;
return Guid.TryParse(value, out x);
}
}
And here's how ...
How to define a preprocessor symbol in Xcode
..., and select "Add User-Defined Setting". The new setting name should be GCC_PREPROCESSOR_DEFINITIONS, and you can type your definitions in the right-hand field.
Per Steph's comments, the full syntax is:
constant_1=VALUE constant_2=VALUE
Note that you don't need the '='s if you just want to #defi...
Stop an input field in a form from being submitted
...nts it from being submitted? Cool, I didn't know that. Does this work on all browsers? Is it part of a standard, or is it an implementation quirk?
– BlairHippo
Jun 9 '10 at 17:12
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Invoking JavaScript code in an iframe from the parent page
...oes not work for my gadget, here is my code document.getElementById('remote_iframe_0').contentWindow.my.create_element_gadget('verify_user');" remote_iframe_0 is created programmaticaly by a apache shindig server but window.parent.document.getElementById('remote_iframe_0').contentWindow.my.cr...
Streaming a video file to an html5 video player with Node.js so that the video controls continue to
...to get the size of the file without reading the whole file into memory. Finally, use fs.createReadStream to send the requested part to the client.
var fs = require("fs"),
http = require("http"),
url = require("url"),
path = require("path");
http.createServer(function (req, res) {
if ...
Remove shadow below actionbar
...PDATE:
As @Quinny898 stated, on Android 5.0 this has changed, you have to call setElevation(0) on your action bar. Note that if you're using the support library you must call it to that like so:
getSupportActionBar().setElevation(0);
...