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What's wrong with nullable columns in composite primary keys?
...key creation. If this was just a retrieval problem, you could use where pk_1 = 'a' and pk_2 = 'b' with normal values, and switch to where pk_1 is null and pk_2 = 'b' when there are nulls.
– EoghanM
Mar 15 '13 at 9:59
...
How do I use cascade delete with SQL Server?
...etting enabled.
Something like:
ALTER TABLE dbo.T2
DROP CONSTRAINT FK_T1_T2 -- or whatever it's called
ALTER TABLE dbo.T2
ADD CONSTRAINT FK_T1_T2_Cascade
FOREIGN KEY (EmployeeID) REFERENCES dbo.T1(EmployeeID) ON DELETE CASCADE
...
Calculating Distance between two Latitude and Longitude GeoCoordinates
...tic UnitOfLength Miles = new UnitOfLength(1);
private readonly double _fromMilesFactor;
private UnitOfLength(double fromMilesFactor)
{
_fromMilesFactor = fromMilesFactor;
}
public double ConvertFromMiles(double input)
{
return input*_fromMilesFactor;
}
...
Can't install Ruby under Lion with RVM – GCC issues
...extra parameter rvm install 1.9.3 --with-gcc=clang --with-readline-dir=$rvm_path/usr it installed successfully.
– leandro
Nov 27 '11 at 13:01
7
...
Nginx缓存解决方案：SRCache - 更多技术 - 清泛网 - 专注C/C++及内核技术
...。
闲言碎语不多讲，表一表Nginx配置文件长啥样：
lua_shared_dict phoenix_status 100m;
lua_package_path '/path/to/phoenix/include/?.lua;/path/to/phoenix/vendor/?.lua;;';
init_by_lua_file /path/to/phoenix/config.lua;
server {
listen 80;
server_name foo.com;
...
Saving interactive Matplotlib figures
...can even extract the data from the plots:
data = figx.axes[0].lines[0].get_data()
(It works for lines, pcolor & imshow - pcolormesh works with some tricks to reconstruct the flattened data.)
I got the excellent tip from Saving Matplotlib Figures Using Pickle.
...
Eclipse hangs on loading workbench
...
#
#
# error
#
# show an error message and exit
#
# params:
# 1: l_msg - the message to display
error() {
local l_msg="$1"
echo "error: $l_msg" 1>&2
exit 1
}
#
# autoinstall
#
# check that l_prog is available by calling which
# if not available install from given package de...
When to use symbols instead of strings in Ruby?
...eference the symbol, saving memory. So every time the interpreter reads :my_key it can take it from memory instead of instantiate it again. This is less expensive than initializing a new string every time.
You can get a list all symbols that are already instantiated with the command Symbol.all_sym...
C# HttpClient 4.5 multipart/form-data upload
... string url = "myAddress/myWS/api/Home/SendImage?foto="; await _client.PostAsync(url, requestContent); return "ok"; }
– atapi19
Jan 29 '18 at 14:59
...
Python timedelta in years
...
from dateutil.relativedelta import relativedelta
def yearsago(years, from_date=None):
if from_date is None:
from_date = datetime.now()
return from_date - relativedelta(years=years)
If you'd rather stick with the standard library, the answer is a little more complex::
from dateti...