大约有 7,000 项符合查询结果（耗时：0.0297秒） [XML]
Django CharField vs TextField
...nce among these three types", but AFAIK there are some differences in e.g. MySQL, so this is something to keep in mind.
A good rule of thumb is that you use CharField when you need to limit the maximum length, TextField otherwise.
This is not really Django-specific, also.
...
Is there a way for non-root processes to bind to “privileged” ports on Linux?
...recent kernel, it is indeed possible to use this to start a service as non-root but bind low ports. The short answer is that you do:
setcap 'cap_net_bind_service=+ep' /path/to/program
And then anytime program is executed thereafter it will have the CAP_NET_BIND_SERVICE capability. setcap is in th...
“[notice] child pid XXXX exit signal Segmentation fault (11)” in apache error.log [closed]
I am using Apache/PHP/MySQL stack.
Using as framework CakePHP.
3 Answers
3
...
Add a column to existing table and uniquely number them on MS SQL Server
...
It would help if you posted what SQL database you're using. For MySQL you probably want auto_increment:
ALTER TABLE tableName ADD id MEDIUMINT NOT NULL AUTO_INCREMENT KEY
Not sure if this applies the values retroactively though. If it doesn't you should just be able to iterate over you...
How do I calculate square root in Python?
...valuate to 0.
And for the record, the preferred way to calculate a square root is this:
import math
math.sqrt(x)
share
|
improve this answer
|
follow
|
...
In the shell, what does “ 2>&1 ” mean?
.../tmp /tnt
ls: cannot access /tnt: No such file or directory
drwxrwxrwt 118 root root 196608 Jan 7 11:49 /tmp
$ ls -ld /tmp /tnt >/dev/null
ls: cannot access /tnt: No such file or directory
$ ls -ld /tmp /tnt 2>/dev/null
drwxrwxrwt 118 root root 196608 Jan 7 11:49 /tmp
(Expecting you don't...
How can I query a value in SQL Server XML column
...
select
Roles
from
MyTable
where
Roles.value('(/root/role)[1]', 'varchar(max)') like 'StringToSearchFor'
These pages will show you more about how to query XML in T-SQL:
Querying XML fields using t-sql
Flattening XML Data in SQL Server
EDIT
After playing with it a little b...
How to set the context path of a web application in Tomcat 7.0
I know that I can rename my webapp (or it's WAR file) to ROOT but this is a terrible way to do it, IMHO. Now I checked out the tomcat doc & it says
...
What is Full Text Search vs LIKE
...
MySQL creates an index from the words of the enabled full-text search column and performs searches on this index. MySQL uses a sophisticated algorithm to determine the rows matched against the search query.
Also, from this S...
Is there a REAL performance difference between INT and VARCHAR primary keys?
...e performance difference between using INT vs. VARCHAR as a primary key in MySQL? I'd like to use VARCHAR as the primary key for reference lists (think US States, Country Codes) and a coworker won't budge on the INT AUTO_INCREMENT as a primary key for all tables.
...