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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...
How to create a self-signed certificate with OpenSSL
...e a CA)", then said, "5. Install the CA certificate on the client". If the root key became compromised, a malicious person could sign a cert for any domain with that key, and if they trick you into going to their website, they can now do a man-in-the-middle attack. Is there a way to create the root ...
How exactly does a generator comprehension work?
...iterables, something like a cursor which moves on a resource. If you know mysql cursor or mongodb cursor, you may be aware of that the whole actual data never gets loaded into the memory at once, but one at a time. Your cursor moves back and forth, but there is always a one row/list element in memo...
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...
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...
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.
...
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
...
“[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...
CSS background-image - What is the correct usage?
...out of the CSS folder tree you should use absolute path or relative to the root path (starting with /)
3) you should use complete declaration for background-image to make it behave consistently across standards compliant browsers like:
background:blue url('/images/clouds.jpg') no-repeat scroll lef...