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Best way to select random rows PostgreSQL
I want a random selection of rows in PostgreSQL, I tried this:
12 Answers
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How to Select Columns in Editors (Atom,Notepad++, Kate, VIM, Sublime, Textpad,etc) and IDEs (NetBean
How to select columns in Editors and IDEs to columnar delete, insert or replace some characters ?
21 Answers
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What does $$ mean in the shell?
...e mktemp option -t is now deprecated (I think because of problems with the char -). Use mktemp ${tempfoo}.XXXXXX these days. I take the liberty to update your post.
– Sebastian
Jan 10 '14 at 11:44
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Why is SELECT * considered harmful?
Why is SELECT * bad practice? Wouldn't it mean less code to change if you added a new column you wanted?
15 Answers
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Difference between EXISTS and IN in SQL?
...way to avoid counting:
--this statement needs to check the entire table
select count(*) from [table] where ...
--this statement is true as soon as one match is found
exists ( select * from [table] where ... )
This is most useful where you have if conditional statements, as exists can be a lot ...
Display two files side by side
....txt does a better job than paste one.txt two.txt and removing diffs extra chars that are displayed with sed is trivial comparing with writing/remembering an awk script. Even with both as functions in .bash_rc longer != better, more readable, faster.. what is the advantage here?
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jQuery get selected option value (not the text, but the attribute 'value')
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04/2020: Corrected old answer
Use :selected psuedo selector on the selected options and then use the .val function to get the value of the option.
$('select[name=selector] option').filter(':selected').val()
Side note: Using filter is better then using :sele...
Vim: faster way to select blocks of text in visual mode
I have been using vim for quite some time and am aware that selecting blocks of text in visual mode is as simple as SHIFT + V and moving the arrow key up or down line-by-line until I reach the end of the block of text that I want selected.
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Using union and order by clause in mysql
...criteria from a table based on distance for a search on my site.
The first select query returns data related to the exact place search .
The 2nd select query returns data related to distance within 5 kms from the place searched.
The 3rd select query returns data related to distance within 5-15 kms f...
INSERT INTO vs SELECT INTO
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They do different things. Use INSERT when the table exists. Use SELECT INTO when it does not.
Yes. INSERT with no table hints is normally logged. SELECT INTO is minimally logged assuming proper trace flags are set.
In my experience SELECT INTO is most commonly used with intermediate d...