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Swapping column values in MySQL
...test s1, swap_test s2 SET s1.x=s1.y, s1.y=s2.x WHERE s1.id=s2.id;
Essentially, the 1st table is the one getting updated and the 2nd one is used to pull the old data from.
Note that this approach requires a primary key to be present.
This is my test schema:
CREATE TABLE `swap_test` (
`id` int(1...
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock'
I installed LAMP on Ubuntu 12.04 LTS (Precise Pangolin) and then set root password on phpMyAdmin . I forgot the password and now I am unable to login. When I try to change password through terminal I get:
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How to increase the gap between text and underlining in CSS
...w property text-underline-offset (as well as text-decoration-thickness) to allow control over the exact placement of an underline. As of this writing, it's an early-stage draft and has not been implemented by any browser, but it looks like it will eventually make the technique below obsolete.
Origi...
Commenting multiple lines in DOS batch file
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Wow, didn't know notepad++ has such a nice feature! Actually really missed it because I'm used to `Ctrl+7' in Eclipse. Voted up to 42 ;)
– Danny Lo
Dec 6 '15 at 14:45
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Meaning of numbers in “col-md-4”,“ col-xs-1”, “col-lg-2” in Bootstrap
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the numbers (1-12) represent a portion of the total width of any div
all divs are divided into 12 columns
so, col-*-6 spans 6 of 12 columns (half the width), col-*-12 spans 12 of 12 columns (the entire width), etc
So, if you want two equal columns to span a div, write
<div class="col-xs-...
How to find the kth largest element in an unsorted array of length n in O(n)?
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This is called finding the k-th order statistic. There's a very simple randomized algorithm (called quickselect) taking O(n) average time, O(n^2) worst case time, and a pretty complicated non-randomized algorithm (called introselect) ...
no gravity for scrollview. how to make content inside scrollview as center
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I had the same issue and finally figured it out. This is for a vertical ScrollView.
Put your ScrollView inside a RelativeLayout and center it in the RelativeLayout. In order for this to work, your ScrollView should have
android:layout_height="wrap_c...
What are namespaces?
...espacing does for functions and classes what scope does for variables. It allows you to use the same function or class name in different parts of the same program without causing a name collision.
In simple terms, think of a namespace as a person's surname. If there are two people named "John" yo...
MySQL Creating tables with Foreign Keys giving errno: 150
... CONSTRAINT's ON DELETE rule is SET NULL make sure the foreign key can actually be NULL! I spent 30 minutes reading this answer over and over, making sure my tables met the conditions but still getting Error 150. Then I noticed my FK was a NOT NULL field meaning the rule was impossible to apply.
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How to export JavaScript array info to csv (on client side)?
...ure but I need to do this using JavaScript. I am using Dojo 1.8 and have all the attribute info in array, which looks like this:
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