I want to convert the db with innodb tables into myisam, all of them. How can I do these? there are some foreign keys exist among tables.
how can I make this in the best way?
Yet another newbie question..
Let's say I have an user table in declarative mode:
class User(Base):
__tablename__ = 'user'
id = Column(u'id', Integer(), primary_key=True)
name = Column(u'name', String(50))
When I have a list of users identifiers, I fetch them from db with:
user_ids = [1, 2, 3, 4, 5]
users = Session.query(User).filter(User.id.in_(user_ids)).all()
I dislike using in_ because I think I learned it has bad performance on indexed fields
(is that true/false?).
Anyway, is there a better way doing that query?
Thanks!
I have a DB schema composed of MYISAM tables, i am interested to delete old records from time to time from some of the tables.
I know that delete does not reclaim the memory space, but as i found in a description of DELETE command, inserts may reuse the space deleted
In MyISAM tables, deleted rows are maintained in a linked list and subsequent INSERT operations reuse old row positions.
I am interested if LOAD DATA command also reuses the deleted space?
UPDATE
I am also interested how the index space reclaimed?
Hi,
I need to implement the Win2k3 password validation policy. As my application resides on Win2k3 cane we validate the password directly with windows domain password by using LDAP. This is because application design does not want to store 8/more password entry into DB and validate new password against that. As Windows already does same thing and using LDAP we can lookup into windows server.
Can any one please let me know LDAP API to fulfill above requirement in VC++.
Hi , we have create a web application on top of google app engine and python. which is almost about to complete it web front phase. I would also like to make it available almost all part of it to external applications. { via , xml , json , http , as many as possible. } . what's the best way to do it ? any library either for python or django available out ther ?
Thanks.
I can find how to define columns only when doing migrations.
However i do not need to migrate my model.
I want to work with it "virtually".
Does AR read columns data only from db?
Any way to define columns like in DataMapper?
class Post
include DataMapper::Resource
property :id, Serial
property :title, String
property :published, Boolean
end
Now i can play with my model without migrations/connections.
I want to know if its possible based on your experience to use our previous experiences using .net ORMs with nosql db such as MongoDB.
And also if you know samples doing this please refer in your answer.
Hello,
I want to update a blog, by sending an email using php. This is not wordpress, tumblr, or the famous ones.
I could set up an email id, with a specific code in the subject line, but how I get input the contents into the db?
Thanks
Jean
In .NET land I would normally query the database and populate a generic List kind of collection. Then the app would use this.
In Android land I have been reading about DB access and use in apps. Why do most of the docs show the use of a cursor and use of constants to access it? Is this to save on resources perhaps?
when using hibernate with spring, can someone explain how the session unit of work and transactions are handled?
is the transaction started at the beginning of the page request, and committed at the end?
can I have multiple db calls per request, that each have different transaction levels? e.g. some are left as default, while others are read-uncommitted?
If you do a search for:
http://www.google.co.uk/search?q=0x57414954464F522044454C4159202730303A30303A313527&hl=en&start=30&sa=N
you will see a lot of examples of an attempted hack along the lines of:
1) declare @q varchar(8000) select @q = 0x57414954464F522044454C4159202730303A30303A313527 exec(@q) --
What is exactly is it trying to do? Which db is it trying to work on?
Do you know of any advisories about this?
Recently i have developed a billing application for my company with Python/Django. For few months everything was fine but now i am observing that the performance is dropping because of more and more users using that applications. Now the problem is that the application is now very critical for the finance team. Now the finance team are after my life for sorting out the performance issue. I have no other option but to find a way to increase the performance of the billing application.
So do you guys know any performance optimization techniques in python that will really help me with the scalability issue
As I continue to build more and more websites and web applications I am often asked to store user's passwords in a way that they can be retrieved if/when the user has an issue (either to email a forgotten password link, walk them through over the phone, etc.) When I can I fight bitterly against this practice and I do a lot of ‘extra’ programming to make password resets and administrative assistance possible without storing their actual password.
When I can’t fight it (or can’t win) then I always encode the password in some way so that it at least isn’t stored as plaintext in the database—though I am aware that if my DB gets hacked that it won’t take much for the culprit to crack the passwords as well—so that makes me uncomfortable.
In a perfect world folks would update passwords frequently and not duplicate them across many different sites—unfortunately I know MANY people that have the same work/home/email/bank password, and have even freely given it to me when they need assistance. I don’t want to be the one responsible for their financial demise if my DB security procedures fail for some reason.
Morally and ethically I feel responsible for protecting what can be, for some users, their livelihood even if they are treating it with much less respect.
I am certain that there are many avenues to approach and arguments to be made for salting hashes and different encoding options, but is there a single ‘best practice’ when you have to store them? In almost all cases I am using PHP and MySQL if that makes any difference in the way I should handle the specifics.
Additional Information for Bounty
I want to clarify that I know this is not something you want to have to do and that in most cases refusal to do so is best. I am, however, not looking for a lecture on the merits of taking this approach I am looking for the best steps to take if you do take this approach.
In a note below I made the point that websites geared largely toward the elderly, mentally challenged, or very young can become confusing for people when they are asked to perform a secure password recovery routine. Though we may find it simple and mundane in those cases some users need the extra assistance of either having a service tech help them into the system or having it emailed/displayed directly to them.
In such systems the attrition rate from these demographics could hobble the application if users were not given this level of access assistance, so please answer with such a setup in mind.
Thanks to Everyone
This has been a fun questions with lots of debate and I have enjoyed it. In the end I selected an answer that both retains password security (I will not have to keep plain text or recoverable passwords), but also makes it possible for the user base I specified to log into a system without the major drawbacks I have found from normal password recovery.
As always there were about 5 answers that I would like to have marked correct for different reasons, but I had to choose the best one--all the rest got a +1. Thanks everyone!
Is there a way to have keyup, keypress, blur, and change events call the same function in one line or do I have to do them separately?
The problem I have is that I need to validate some data with a db lookup and would like to make sure that there is no way that the validation is missed weather it is typed or pasted into the box.
I want to use a database which name is stored in a variable. How do I do this?
I first thought this would work but it doesn't:
exec('use '+@db)
That will not change database context
Suggestions anyone?
My web-app has to deliver db-generated content by email. The HTML need not include javascript but _does have to include images and CSS.
It's a safe bet that most users will be viewing this in Outlook. Are general guidelines different for html destined for email vs. IE?
-schema
CREATE TABLE `ratings` (
`id` int(11) NOT NULL default '0',
`rating` int(11) NOT NULL default '1',
`rating_start` datetime NOT NULL default '0000-00-00 00:00:00',
PRIMARY KEY (`id`)
) TYPE=MyISAM
-myprogram.php
foreach($ids as $id){
$sql = "SELECT rating FROM ratings WHERE id = '$id' AND rating_start >= NOW()";
$sql .= "ORDER BY rating_start DESC LIMIT 1;"
$ret = $db->execute($id);
}
Can I teke same date from a Query?
by using id IN (".implode(",",$ids).") and GROUP BY id
This line:
used_emails = [row.email for row
in db.execute(select([halo4.c.email], halo4.c.email!=''))]
Returns:
['[email protected]', '[email protected]', '[email protected]', '[email protected]', '[email protected]']
I use this to find a match:
if recipient in used_emails:
If it finds a match I need to pull another field (halo4.c.code) from the database in the same row. Any suggestions on how to do this?
Is there anyway invoke a PHP page / function when a record being inserted in to the mysql db table. We dont have control over the record insertion procedure.Is there some thing called trigger which can call a PHP script back ?
I currently have a 120Gib SSD which is pretty fast for things like game loading times and video editing.
However, I was wondering about getting another identical drive and hooking it up with a striping RAID array in hardware (I boot multiple operating systems).
This would have the dual benefits of providing a larger logical drive, while also providing greater performance.
However, I have a few questions:
What kind of performance increase can I expect to see with a pair of good quality SSDs?
How expensive is a quality desktop RAID controller?
Will the controller present the OS with a single logical drive? Does this mean I can still partition it and multi-boot? Basically, can I treat the RAID controller as "a hard drive" at the OS level?
My company is currently looking to replace our current solution used for monitoring our web-based enterprise solutions for both up-time and performance. Please note this is not intended to be a network monitoring-type solution (internally we currently use Nagios). If anyone has a provider that they have had a positive experience with, it would be much appreciated.
Here is a list of our requirements:
• Must have a large number of probes/agents around the globe to be representative of our customer base
• Must have a flexible scripting capability to automate multi-step user actions
• 24 hour a day monitoring
• Flexible alerting system
• Report generation capability
• Mimic browser specific monitoring (optional, not a must-have)
Hi,
Is it possible for entering values into dropdown and saving that values to DB? If yes please help me by giving the code for that. Thanks in advance
Ok, So I have to generate very complex reports from my DB.
If I am to do it with SQL the query themselves will be complex, and I will have to do some more manipulation on the results later, code level.
How do libraries like Jasper Reports/ Crystal Reports and friends save me time when developing such reports?
What will they give me?
I have web server with OS RHEL 6.2 and Mysql 5.5.23 on another server and the web server can read from Mysql server without problem, but some time I got this error:
[Sun Sep 23 06:13:07 2012] [error] [client XXXXX] DBI connect('XXXX:192.168.1.2:3306','XXX',...) failed: Can't create TCP/IP socket (24) at /var/www/html/file.pm line 199.
my question :
What does this error mean (Can't create TCP/IP socket (24))? is it OS error or Mysql error ?
perl -v
This is perl, v5.10.1 (*) built for x86_64-linux-thread-multi
mysql -V
mysql Ver 14.14 Distrib 5.5.23, for Linux (x86_64) using readline 5.1
su - mysql -s /bin/bash -c 'ulimit -a'
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 127220
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 10240
cpu time (seconds, -t) unlimited
max user processes (-u) 1024
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited