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Postgres: INSERT if does not exist already
...onditional INSERT in PostgreSQL:
INSERT INTO example_table
(id, name)
SELECT 1, 'John'
WHERE
NOT EXISTS (
SELECT id FROM example_table WHERE id = 1
);
CAVEAT This approach is not 100% reliable for concurrent write operations, though. There is a very tiny race condition between...
How to generate unique ID with node.js
...
The fastest possible way to create random 32-char string in Node is by using native crypto module:
const crypto = require("crypto");
const id = crypto.randomBytes(16).toString("hex");
console.log(id); // => f9b327e70bbcf42494ccb28b2d98e00e
...
What is a regular expression for a MAC Address?
... The second will incorrectly match strings which contain non-hex characters such as g.
– Binary Phile
Feb 25 '15 at 15:32
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Removing an item from a select box
How do I remove items from, or add items to, a select box? I'm running jQuery, should that make the task easier. Below is an example select box.
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How to split a string into an array of characters in Python?
... to look around the web for answers to splitting a string into an array of characters but I can't seem to find a simple method
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Newline in string attribute
... encoded value to represent a literal. In this case, I used the line feed (char 10). If you want to do "classic" vbCrLf, then you can use 

By the way, note the syntax: It's the ampersand, a pound, the letter x, then the hex value of the character you want, and then finally a sem...
SELECT INTO a table variable in T-SQL
Got a complex SELECT query, from which I would like to insert all rows into a table variable, but T-SQL doesn't allow it.
8...
How to get multiple select box values using jQuery?
How to get multiple select box values using jQuery?
8 Answers
8
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Set select option 'selected', by value
I have a select field with some options in it. Now I need to select one of those options with jQuery. But how can I do that when I only know the value of the option that must be selected?
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How to hide a in a menu with CSS?
...hat Chrome, it seems, will not allow me to hide <option> in a <select> . Firefox will.
13 Answers
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