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If table exists drop table then create it, if it does not exist just create it
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Just put DROP TABLE IF EXISTS `tablename`; before your CREATE TABLE statement.
That statement drops the table if it exists but will not throw an error if it does not.
s...
Macro vs Function in C
...le with control-flow constructs:
#define swap(x, y) t = x; x = y; y = t;
if (x < y) swap(x, y); -->
if (x < y) t = x; x = y; y = t; --> if (x < y) { t = x; } x = y; y = t;
The usual strategy for fixing this is to put the statements inside a "do { ... } while (0)" loop.
If you hav...
List all base classes in a hierarchy of given class?
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If your class inherits from a class that inherits from a class, only the first part of the chain will be in its __bases__
– Boris
Nov 25 '19 at 22:56
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Animate text change in UILabel
...t the license stuff. What prevents people from using it in commercial apps now?
– Esqarrouth
Jun 5 '15 at 5:44
2
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How to provide user name and password when connecting to a network share
...efer the latter, as I sometimes need to maintain multiple credentials for different locations. I wrap it into an IDisposable and call WNetCancelConnection2 to remove the creds afterwards (avoiding the multiple usernames error):
using (new NetworkConnection(@"\\server\read", readCredentials))
using ...
pretty-print JSON using JavaScript
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Pretty-printing is implemented natively in JSON.stringify(). The third argument enables pretty printing and sets the spacing to use:
var str = JSON.stringify(obj, null, 2); // spacing level = 2
If you need syntax highlighting, you might use some regex magic like so:
function...
Count how many files in directory PHP
...eople are saying this is confusing for some developers, should we add that if one is using namespaces (since this method requires a recent version of PHP in any case), then one must also specify the namespace: $fi = new \FilesystemIterator(DIR, \FilesystemIterator::SKIP_DOTS);
–...
Error: Could not find or load main class in intelliJ IDE
...and then followed the steps mentioned by @Kishore over here. It is working now.
– Sunny Shekhar
Nov 26 '19 at 5:14
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How to add a progress bar to a shell script?
... (100%)\r'
echo -ne '\n'
In a comment below, puk mentions this "fails" if you start with a long line and then want to write a short line: In this case, you'll need to overwrite the length of the long line (e.g., with spaces).
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AfxGetMainWnd函数解惑 - C/C++ - 清泛网 - 专注C/C++及内核技术
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{
CMainFrame* pMainWnd = (CMainFrame*)AfxGetMainWnd();
if (NULL!=pMainWnd)
{
CView *pView = pMainWnd->GetActiveView();
if (NULL!=pView)
{
CDC *pDC = pView->GetDC();
ASSERT(NULL!=pDC);
pDC-...