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DROP IF EXISTS VS DROP?
Can someone tell me if there is any difference between
5 Answers
5
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LINQ Single vs First
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If you're expecting a Single record, it's always good to be explicit in your code.
I know others have written why you use one or the other, but I thought I'd illustrate why you should NOT use one, when you mean the other.
Not...
How to check if there's nothing to be committed in the current branch?
...dition you care about separately. One might not always care, for example, if there are untracked files in the output of git status.
For example, to see if there are any local unstaged changes, you can look at the return code of:
git diff --exit-code
To check if there are any changes that are st...
Check if a Bash array contains a value
In Bash, what is the simplest way to test if an array contains a certain value?
35 Answers
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jQuery: Check if div with certain class name exists
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You can simplify this by checking the first object that is returned from JQuery like so:
if ($(".mydivclass")[0]){
// Do something if class exists
} else {
// Do something if class does not exist
}
In this case if there is a tr...
What is the idiomatic Go equivalent of C's ternary operator?
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As pointed out (and hopefully unsurprisingly), using if+else is indeed the idiomatic way to do conditionals in Go.
In addition to the full blown var+if+else block of code, though, this spelling is also used often:
index := val
if val <= 0 {
index = -val
}
and if you ...
What is the best way to test for an empty string with jquery-out-of-the-box?
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if (!a) {
// is emtpy
}
To ignore white space for strings:
if (!a.trim()) {
// is empty or whitespace
}
If you need legacy support (IE8-) for trim(), use $.trim or a polyfill.
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Python `if x is not None` or `if not x is None`?
I've always thought of the if not x is None version to be more clear, but Google's style guide and PEP-8 both use if x is not None . Is there any minor performance difference (I'm assuming not), and is there any case where one really doesn't fit (making the other a clear winner for my convent...
PostgreSQL create table if not exists
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This feature has been implemented in Postgres 9.1:
CREATE TABLE IF NOT EXISTS myschema.mytable (i integer);
For older versions, here is a function to work around it:
CREATE OR REPLACE FUNCTION create_mytable()
RETURNS void
LANGUAGE plpgsql AS
$func$
BEGIN
IF EXISTS (SELECT FROM ...
It is more efficient to use if-return-return or if-else-return?
Suppose I have an if statement with a return . From the efficiency perspective, should I use
8 Answers
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