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What does “Document-oriented” vs. Key-Value mean when talking about MongoDB vs Cassandra?
... of a database at the top level, then collections which are like tables in MySQL (for example) and then documents which are contained within the collection, like rows in MySQL. Each document has a field and a value where this is similar to columns and values in MySQL. Fields can be simple key / valu...
Django-Admin: CharField as TextArea
...form = BookForm
admin.site.register(Book, BookAdmin)
If you are using a MySQL DB, your column length will usually be autoset to 250 characters, so you will want to run an ALTER TABLE to change the length in you MySQL DB, so that you can take advantage of the new larger Textarea that you have in y...
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...
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.
...
“[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
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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)
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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
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