大约有 48,000 项符合查询结果（耗时：0.0414秒） [XML]
Can a foreign key be NULL and/or duplicate?
...from a FK without adding a further constraint on the field. So you have an order table and the order details table for instance. If the customer orders ten items at one time, he has one order and ten order detail records that contain the same orderID as the FK.
...
OR is not supported with CASE Statement in SQL Server
.... CASE expressions can be used within the SELECT statement, WHERE clauses, Order by clause, HAVING clauses, Insert, UPDATE and DELETE statements.
A CASE expression has the following two formats:
Simple CASE expression
CASE expression
WHEN expression1 THEN Result1
WHEN expression2 THEN Result2
EL...
How to make --no-ri --no-rdoc the default for gem install?
... Anyway to make this a system wide default without editing /etc/skel and every user's home directory?
– Hackeron
Jan 13 '11 at 3:43
42
...
Split a vector into chunks in R
... f)
if(force.number.of.groups) {
g.names <- names(g)
g.names.ordered <- as.character(sort(as.numeric(g.names)))
} else {
g.names <- names(g[-length(g)])
g.names.ordered <- as.character(sort(as.numeric(g.names)))
g.names.ordered <- c(g.names.ordered, "overflow"...
Finding duplicate rows in SQL Server
...CT
orgName, id,
ROW_NUMBER() OVER (PARTITION BY orgName ORDER BY id) AS intRow
FROM organizations
) AS d
WHERE intRow != 1
Edit: SQL Server 2000 doesn't have the ROW_NUMBER() function. Instead, you can use:
SELECT
o.id, o.orgName, d.intCount
FROM (
SELECT orgName,...
Separation of business logic and data access in django
...ation e-mail is sent to the user
and an entry is added to the system log
(etc. etc.)
Such scenario's are useful to see how different parts of your infrastructure can be affected by a single command – in this case your database (some kind of 'active' flag), your mail server, your system log, etc...
What is a simple/minimal browserconfig.xml for a web site
...enerators your browserconfig.xml AND all your apple-touch-* icons, favicon etc. Basically a one stop website for generating everything once.
share
|
improve this answer
|
fol...
Software Design vs. Software Architecture [closed]
...gn patterns, there are architectural patterns: MVC, 3-tier layered design, etc.
Software design is about designing the individual modules / components. What are the responsibilities, functions, of module x? Of class Y? What can it do, and what not? What design patterns can be used?
So in short, S...
Can a variable number of arguments be passed to a function?
...
# 1
# 2
# 3
# banan = 123
They must be both declared and called in that order, that is the function signature needs to be *args, **kwargs, and called in that order.
share
|
improve this answer
...
OS detecting makefile
...
I was recently experimenting in order to answer this question I was asking myself. Here are my conclusions:
Since in Windows, you can't be sure that the uname command is available, you can use gcc -dumpmachine. This will display the compiler target.
There...