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ORA-00979 not a group by expression
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You must put all columns of the SELECT in the GROUP BY or use functions on them which compress the results to a single value (like MIN, MAX or SUM).
A simple example to understand why this happens: Imagine you have a database like this:
FOO BAR
0 A
0 ...
What is a “callback” in C and how are they implemented?
...ude <string.h>
typedef struct {
int iValue;
int kValue;
char label[6];
} MyData;
int cmpMyData_iValue (MyData *item1, MyData *item2)
{
if (item1->iValue < item2->iValue) return -1;
if (item1->iValue > item2->iValue) return 1;
return 0;
}
int cmpMyDa...
ConnectionTimeout versus SocketTimeout
... answer. This means that the server has been shut down, you used the wrong IP/DNS name, wrong port or the network connection to the server is down.
A socket timeout is dedicated to monitor the continuous incoming data flow. If the data flow is interrupted for the specified timeout the connection is...
How to avoid variable substitution in Oracle SQL Developer with 'trinidad & tobago'
...| ' Tobago');
insert into table99 values('Trinidad &' || ' Tobago');
SELECT * FROM table99;
update table99 set col1 = 'Trinidad and Tobago' where col1 = 'Trinidad &'||' Tobago';
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How to make an OpenGL rendering context with transparent background?
... 0);
assert(hbmpDIB);
assert(bmp_cnt);
if(hbmpDIB)
SelectObject(pdcDIB, hbmpDIB);
}
BOOL CreateHGLRC()
{
DWORD dwFlags = PFD_SUPPORT_OPENGL | PFD_DRAW_TO_BITMAP;
PIXELFORMATDESCRIPTOR pfd ;
memset(&pfd,0, sizeof(PIXELFORMATDESCRIPTOR)) ;
pfd.nSize = size...
how to implement regions/code collapse in javascript
....Collections
Public Module JsMacros
Sub OutlineRegions()
Dim selection As EnvDTE.TextSelection = DTE.ActiveDocument.Selection
Const REGION_START As String = "//#region"
Const REGION_END As String = "//#endregion"
selection.SelectAll()
Dim text As Strin...
项目管理实践教程二、源代码控制【Source Control Using VisualSVN Server ...
...服务器的配置也只是在图像界面上，指定认证方式、访问端口等简单操作；另外，用户权限的管理也是通过图像界面来配置。
2.为什么不用TFS?
回答:
因为我们一开始就是用Subversion和TortioseSVN,所以就没有更换其他的软件。至于T...
What are Aggregates and PODs and how/why are they special?
...ns (10.3) and no virtual base classes (10.1), and
— the constructor selected to copy/move each direct base class subobject is trivial, and
— for each non-static data member of X that is of class type (or array thereof), the constructor
selected to copy/move that member is trivial;
...
Linux command (like cat) to read a specified quantity of characters
...the chars in line 5 and chars 5 to 8 of line 5,
Note: tail -1 is used to select the last line displayed by the head.
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How to choose the id generation strategy when using JPA and Hibernate
...d
uses a database-generated GUID string on MS SQL Server and MySQL.
native
selects identity, sequence or hilo depending upon the capabilities of the underlying database.
assigned
lets the application assign an identifier to the object before save() is called. This is the default strategy if no elem...