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SQL “select where not in subquery” returns no results
...LEFT JOIN / IS NULL: Oracle
NOT IN vs. NOT EXISTS vs. LEFT JOIN / IS NULL: MySQL
There are three ways to do such a query:
LEFT JOIN / IS NULL:
SELECT *
FROM common
LEFT JOIN
table1 t1
ON t1.common_id = common.common_id
WHERE t1.common_id IS NULL
NOT EXISTS:
SELECT *
FROM...
What is the difference between HAVING and WHERE in SQL?
... Methinks you are quoting me out of context. The question was about mySQL's apparent deviation from the Standard, all but the last paragraph of my answer describes the Standard behaviour, and the last alludes to " the implicit GROUP BY clause mentioned in other answers." Are you saying your d...
Open a file with su/sudo inside Emacs
...
If you use helm, helm-find-files supports opening a file as root with C-c r.
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Detect if Visual C++ Redistributable for Visual Studio 2012 is installed
...been finalized, yet. As I'm guessing the upper-most keys of:
[HKEY_CLASSES_ROOT\Installer\Dependencies\,,amd64,14.0,bundle]
and
[HKEY_CLASSES_ROOT\Installer\Dependencies\,,x86,14.0,bundle]
are subject to change, or at least have different nested GUIDs, I'm going to use list the key that ends with a...
Service Temporarily Unavailable Magento?
...d if so delete it.
Magento 1.x : maintenance.flag file is in : magento root directory
Magento 2.x : maintenance.flag file is in : var folder
When Magento is performing certain tasks it temporarily creates this file. Magento checks for its existence and if it's there will send users to ...
Linux scp 远程文件上传下载,指定端口 - 操作系统(内核) - 清泛网 - 专注C...
...定端口linux-scp1、默认22端口上传、下载文件:scp test tgz root@xxx xxx xxx xxx: tmpscp root@xxx xxx xxx xxx: tmp test tgz 2、指定端口:scp -P8888 root@xxx xxx xxx xxx: tmp test tgz 1、默认22端口上传、下载文件:
scp test.tgz root@xxx.xxx.xxx.xxx:/tmp
scp root@x...
PANIC: Broken AVD system path. Check your ANDROID_SDK_ROOT value [D:\A...
报错如下:PANIC: Broken AVD system path. Check your ANDROID_SDK_ROOT value [D:\APPinventor\AppInventor2\resources\app.asar.unpacked\Emulator\from-Android-SDK]!
What would cause an algorithm to have O(log log n) complexity?
...ly two main routes that will arrive at this runtime.
Shrinking by a Square Root
As mentioned in the answer to the linked question, a common way for an algorithm to have time complexity O(log n) is for that algorithm to work by repeatedly cut the size of the input down by some constant factor on each...
SQL query for today's date minus two months
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If you use MySQL this would become: MyDate < DATE_ADD(NOW(), INTERVAL -2 MONTH)
– Stefan
Feb 27 '14 at 15:51
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Explain Morris inorder tree traversal without using stacks or recursion
...works:
X
/ \
Y Z
/ \ / \
A B C D
First, X is the root, so it is initialized as current. X has a left child, so X is made the rightmost right child of X's left subtree -- the immediate predecessor to X in an inorder traversal. So X is made the right child of B, then current ...