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Django select only rows with duplicate field values
...ne these into a single query:
Literal.objects.filter(name__in=dups)
The extra call to .values('name') after the annotate call looks a little strange. Without this, the subquery fails. The extra values tricks the ORM into only selecting the name column for the subquery.
...
Python List vs. Array - when to use?
...ctl or fctnl).
array.array is also a reasonable way to represent a mutable string in Python 2.x (array('B', bytes)). However, Python 2.6+ and 3.x offer a mutable byte string as bytearray.
However, if you want to do math on a homogeneous array of numeric data, then you're much better off using NumPy,...
Difference between attr_accessor and attr_accessible
...stname" and "role" :
SQL instructions :
CREATE TABLE users (
firstname string,
lastname string
role string
);
I assumed that you set the option config.active_record.whitelist_attributes = true in your config/environment/production.rb to protect your application from Mass assignment exploit...
Multiple line code example in Javadoc comment
...sues (in particular with Generics), e.g.:
* <pre>
* {@code
* Set<String> s;
* System.out.println(s);
* }
* </pre>
Will give correct HTML output:
Set<String> s;
System.out.println(s);
While omitting the @code block (or using a <code> tag) will result in HTML like t...
Any gotchas using unicode_literals in Python 2.6?
...
The main source of problems I've had working with unicode strings is when you mix utf-8 encoded strings with unicode ones.
For example, consider the following scripts.
two.py
# encoding: utf-8
name = 'helló wörld from two'
one.py
# encoding: utf-8
from __future__ import unic...
How to iterate over arguments in a Bash script
... when there are no positional parameters whereas "$*" expands to the empty string -- and yes, there is a difference between no arguments and one empty argument. See ${1:+"$@"} in /bin/sh`.
– Jonathan Leffler
Dec 12 '14 at 22:12
...
Regular expression to match a line that doesn't contain a word
...ng negative look-arounds:
^((?!hede).)*$
The regex above will match any string, or line without a line break, not containing the (sub)string 'hede'. As mentioned, this is not something regex is "good" at (or should do), but still, it is possible.
And if you need to match line break chars as wel...
ORA-00979 not a group by expression
...ECT cr.review_sk,
cr.cs_sk,
cr.full_name,
tolist(to_char(cf.fact_date, 'mm/dd/yyyy')) "appt",
cs.cs_id,
cr.tracking_number
from review cr, cs, fact cf
where cr.cs_sk = cs.cs_sk
and UPPER(cs.cs_id) like '%' || UPPER(i_cs_id) || '%'
and row_delete_da...
How to get Time from DateTime format in SQL?
...AttDate as time) [time]
FROM yourtable
Earlier versions:
SELECT convert(char(5), AttDate, 108) [time]
FROM yourtable
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C语言判断文件是否存在 - C/C++ - 清泛网 - 专注C/C++及内核技术
...是否存在用函数access，头文件是io.h，原型：int access(const char *filename, int amode);amode参数为0时表示检查文件的存在性，如果文件存...用函数access，头文件是io.h，原型：
int access(const char *filename, int amode);
amode参数为0时表示检查文...