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How to do SELECT COUNT(*) GROUP BY and ORDER BY in Django?
...lvaro has answered the Django's direct equivalent for GROUP BY statement:
SELECT actor, COUNT(*) AS total
FROM Transaction
GROUP BY actor
is through the use of values() and annotate() methods as follows:
Transaction.objects.values('actor').annotate(total=Count('actor')).order_by()
However ...
Get all table names of a particular database by SQL query?
...different sql dbms deal with schemas.
Try the following
For SQL Server:
SELECT TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_CATALOG='dbName'
For MySQL:
SELECT TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_SCHEMA='dbN...
LAST_INSERT_ID() MySQL
...RT INTO table2 (parentid,otherid,userid) VALUES (LAST_INSERT_ID(), 4, 1);
SELECT MAX(id) FROM table1;
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How to put a UserControl into Visual Studio toolBox
...ialog with registered components pops up. in this dialog click "Browse" to select your assembly with the usercontrol you want to use.
PS.
This assembly should be registered before.
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[精华]VC++对话框程序打印及打印预览的实现 - C/C++ - 清泛网 - 专注C/C++及内核技术
...ew.h”
#include “MyFrame.h”
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE［］=__FILE__;
#define new DEBUG_NEW
#endif
//////////////////////////////////////////
IMPLEMENT_DYNCREATE(CMyPreviewView, CPreviewView)
CMyPreviewView::CMyPreviewView()
{
}
CMyPreviewView::~CMyPreview...
How do you copy the contents of an array to a std::vector in C++ without looping?
...ven when a function expects c-style arrays you can use vectors:
vector<char> v(50); // Ensure there's enough space
strcpy(&v[0], "prefer vectors to c arrays");
Hope that helps someone out there!
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Switch case with fallthrough?
...
Or in this simple case a character class [23])
– SiegeX
Apr 6 '11 at 6:50
4
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How to get the error message from the error code returned by GetLastError()?
...dated (11/2017) to take into consideration some comments.
Easy example:
wchar_t buf[256];
FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
buf, (sizeof(buf) / sizeof(wchar_t)),...
ADB not recognising Nexus 4 under Windows 7
...nstall the generic 'MTP device driver'
Right clicked on the new device and selected 'Update Driver'
Selected 'Have Disk' and pointed it to [android-sdk-dir]\extras\google
Watched an 'ADB' driver install.
Opened Eclipse to successfully run on my Nexus 4.
Good luck!
...
How to stop a program running under Eclipse?
...r. For this you can open up the devices window (in the debug perspective), select the process and then press the stop button on the same window.
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