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Counting DISTINCT over multiple columns
... two columns.
Once it is persisted, provided the column is deterministic and you are using "sane" database settings, it can be indexed and / or statistics can be created on it.
I believe a distinct count of the computed column would be equivalent to your query.
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Attach parameter to button.addTarget action in Swift
...parameters in addTarget:.One alternative is set the tag property of button and do work based on the tag.
button.tag = 5
button.addTarget(self, action: "buttonClicked:",
forControlEvents: UIControlEvents.TouchUpInside)
Or for Swift 2.2 and greater:
button.tag = 5
button.addTarget(self,action...
What does the Ellipsis object do?
...nterpretation is purely up to whatever implements the __getitem__ function and sees Ellipsis objects there, but its main (and intended) use is in the numpy third-party library, which adds a multidimensional array type. Since there are more than one dimensions, slicing becomes more complex than just...
java: ArrayList - how can i check if an index exists?
I'm using ArrayList<String> and I add data at specific indices,
how can I check if a specific index exists?
11 Ans...
How to reliably guess the encoding between MacRoman, CP1252, Latin1, UTF-8, and ASCII
...ct thing would be to guess the encoding, then use the native2ascii tool to convert all non-ASCII characters to Unicode escape sequences.
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Meaning of $? (dollar question mark) in shell scripts
...
This is the exit status of the last executed command.
For example the command true always returns a status of 0 and false always returns a status of 1:
true
echo $? # echoes 0
false
echo $? # echoes 1
From the manual: (acessible by calling man bash in your shell)
$?...
How to declare a variable in MySQL?
... refer to a variable that has not been
initialized, it has a value of NULL and a type of string.
SELECT @var_any_var_name
You can initialize a variable using SET or SELECT statement:
SET @start = 1, @finish = 10;
or
SELECT @start := 1, @finish := 10;
SELECT * FROM places WHERE place BET...
Why in Java 8 split sometimes removes empty strings at start of result array?
...ehavior of String.split (which calls Pattern.split) changes between Java 7 and Java 8.
Documentation
Comparing between the documentation of Pattern.split in Java 7 and Java 8, we observe the following clause being added:
When there is a positive-width match at the beginning of the input sequen...
Downcasting in Java
... @UnKnown: it shouldn't. Double check that you actually compiled and ran that version and if you can still reproduce it, post a separate question (with an SSCCE).
– Joachim Sauer
Apr 20 '16 at 16:04
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Most efficient T-SQL way to pad a varchar on the left to a certain length?
...right('XXXXXXXXXXXX'+ rtrim(@str), @n)
where X is your padding character and @n is the number of characters in the resulting string (assuming you need the padding because you are dealing with a fixed length).
But as I said you should really avoid doing this in your database.
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