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Difference between View and table in sql
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A table contains data, a view is just a SELECT statement which has been saved in the database (more or less, depending on your database).
The advantage of a view is that it can join data from several tables thus creating a new view of it. Say you have a database w...
add column to mysql table if it does not exist
...rade_database_1_0_to_2_0()
BEGIN
-- rename a table safely
IF NOT EXISTS( (SELECT * FROM information_schema.COLUMNS WHERE TABLE_SCHEMA=DATABASE()
AND TABLE_NAME='my_old_table_name') ) THEN
RENAME TABLE
my_old_table_name TO my_new_table_name,
END IF;
-- add a column safely
IF NO...
Visual Studio hot keys change occasionally, specifically F6 vs Ctrl-Shift-B for building. WHY?
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This is because you might have selected "General Development Settings" as your default environment settings for your Visual Studio (which usually we do on the first launch of VS after installing it as it pops up a dialogue box to choose default environment...
How do I clear all options in a dropdown box?
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You can use the following to clear all the elements.
var select = document.getElementById("DropList");
var length = select.options.length;
for (i = length-1; i >= 0; i--) {
select.options[i] = null;
}
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Imply bit with constant 1 or 0 in SQL Server
Is it possible to express 1 or 0 as a bit when used as a field value in a select statement?
8 Answers
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ERROR ITMS-9000: “Redundant Binary Upload. There already exists a binary upload with build version '
...umber just has to be unique (and higher) for each binary that is uploaded (select the Target, then Xcode -> General -> Build, see the picture below).
For example in the image below the build uploaded has version 3.1.4 (3.75 in the older image) and the build number is 1. Thus, after uploading t...
Where is the “Create Unit Tests” selection?
..."Show commands containing" text box to filter out CreateUnitTests command, select it. Choose "Text Editor" in "Use new shortcut in" combo, and press shortcut you want in "Press shortcut keys" text field (e.g., Ctrl+T, Ctrl+C). Finally, press Assign button. Enjoy!
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Android: ListView elements with multiple clickable buttons
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For future readers:
To select manually the buttons with the trackball use:
myListView.setItemsCanFocus(true);
And to disable the focus on the whole list items:
myListView.setFocusable(false);
myListView.setFocusableInTouchMode(false);
myListVie...
How to use querySelectorAll only for elements that have a specific attribute set?
I'm trying to use document.querySelectorAll for all checkboxes that have the value attribute set.
3 Answers
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Bash variable scope
...do
var="abc"
echo $var | xsel -i -p # redirect stdin to the X primary selection
done
var=$(xsel -o -p) # redirect back to stdout
echo $var
EDIT:
Here, xsel is a requirement (install it).
Alternatively, you can use xclip:
xclip -i -selection clipboard
instead of
xsel -i -p
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