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SQL join: selecting the last records in a one-to-many relationship
... features of your RDBMS to analyze the optimization plan. E.g. EXPLAIN on MySQL.
Some people use subqueries instead of the solution I show above, but I find my solution makes it easier to resolve ties.
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What is a stack trace, and how can I use it to debug my application errors?
... multiple "Caused by" sections. For these, you typically want to find the "root cause", which will be one of the lowest "Caused by" sections in the stack trace. In our case, it's:
Caused by: java.lang.NullPointerException <-- root cause
at com.example.myproject.Book.getId(Book.java:22) &...
List All Redis Databases
...
There is no command to do it (like you would do it with MySQL for instance). The number of Redis databases is fixed, and set in the configuration file. By default, you have 16 databases. Each database is identified by a number (not a name).
You can use the following command to kn...
Force SSL/https using .htaccess and mod_rewrite
...e rest. However, on the HTTPS pages, there are forms that submit to my web root. The form specifies the action url as HTTPS. However, since the web root isn't one of those pages that are specified to force HTTPS, my .htaccess then forces a redirect -- which means the POST variables are lost. How do ...
Is it possible to install another version of Python to Virtualenv?
... (/usr/bin/python)
--clear Clear out the non-root install and start from scratch
--no-site-packages Don't give access to the global site-packages dir to
the virtual environment
--unzip-setuptools Unzip Setuptools or Distribute when inst...
Strings as Primary Keys in SQL Database [closed]
...Good explanation. But holds this true for all SQL databases? I've heard of MySQL performance issues when using random UUID as primary key.
– hgoebl
Aug 27 '17 at 11:08
add a c...
Cannot read configuration file due to insufficient permissions
...
I had the same problem when I tried to share the site root folder with another user. Some folder lost the permission.
So I followed the steps to add permission to IIS_IUSRS group as suggested by Afshin Gh.
The problem is this group was not available for me. I am using windows 7....
Unzip a file with php
...he destination to extract to or remove -d yourDestinationDir to extract to root dir.
$master = 'someDir/zipFileName';
$data = system('unzip -d yourDestinationDir '.$master.'.zip');
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What do I need to do to get Internet Explorer 8 to accept a self signed certificate?
...tificates in the following store”.
Click “Browse”, select “Trusted Root Certification Authorities”, and click “OK”.
Back in the wizard, click “Next”, then “Finish”.
If you get a “Security Warning” message box, click “Yes”.
Dismiss the message box with “OK”.
Select T...
Way to go from recursion to iteration
...RecursiveTraversal(x.c, list);
list.Add(x.key);//finally visit root
}
}
The iterative solution:
int? address = null;
AbcTreeNode x = null;
x = root;
address = A;
stack.Push(x);
stack.Push(null)
while (stack.Count >...