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Postgresql GROUP_CONCAT equivalent?
...ROM data_table
GROUP BY id_field
array_agg returns an array, but you can CAST that to text and edit as needed (see clarifications, below).
Prior to version 8.4, you have to define it yourself prior to use:
CREATE AGGREGATE array_agg (anyelement)
(
sfunc = array_append,
stype = anyarray,
...
Get int value from enum in C#
...
Just cast the enum, e.g.
int something = (int) Question.Role;
The above will work for the vast majority of enums you see in the wild, as the default underlying type for an enum is int.
However, as cecilphillip points out, enum...
TCP vs UDP on video stream
...s clients is long due to the singularity of the event. Pre-recorded video-casts typically don't have as much of a problem with this because viewers stagger their replay activity; therefore TCP is more appropriate for replaying a video-on-demand.
IP multicast significantly reduces video bandwidth re...
How can I select the first day of a month in SQL?
...
The casting of a string (i.e. "5/1/2009") to datetime is certainly more legible but we found code a while back that would return the first of the month...
DECLARE @Date DATETIME
//...
SELECT DATEADD(mm, DATEDIFF(mm,0,@Date), 0)
...
When to use std::forward to forward arguments?
... }
std::string to_string (void) const {
auto address = static_cast<const void*>(this);
std::stringstream ss;
ss << address;
return "BankAccount(" + ss.str() + ", cash $" + std::to_string(cash) + ")";
}
};
template<typename T, typename Account&...
Why does this code segfault on 64-bit architecture but work fine on 32-bit?
...
The cast to int* masks the fact that without the proper #include the return type of malloc is assumed to be int. IA-64 happens to have sizeof(int) < sizeof(int*) which makes this problem obvious.
(Note also that because of t...
convert double to int
What is the best way to convert a double to an int ? Should a cast be used?
10 Answers
...
How can I obtain the element-wise logical NOT of a pandas Series?
...
NumPy is slower because it casts the input to boolean values (so None and 0 becomes False and everything else becomes True).
import pandas as pd
import numpy as np
s = pd.Series([True, None, False, True])
np.logical_not(s)
gives you
0 False
1 ...
How to get ALL child controls of a Windows Forms form of a specific type (Button/Textbox)?
...t; GetAll(Control control,Type type)
{
var controls = control.Controls.Cast<Control>();
return controls.SelectMany(ctrl => GetAll(ctrl,type))
.Concat(controls)
.Where(c => c.GetType() == type);
}
To test it in the for...
Select n random rows from SQL Server table
...sOrderDetail table:
SELECT * FROM Sales.SalesOrderDetail
WHERE 0.01 >= CAST(CHECKSUM(NEWID(),SalesOrderID) & 0x7fffffff AS float)
/ CAST (0x7fffffff AS int)
The SalesOrderID column is included in
the CHECKSUM expression so that
NEWID() evaluates once per row to
achi...