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What's the best name for a non-mutating “add” method on an immutable collection?
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In situations like that, I usually go with Concat. That usually implies to me that a new object is being created.
var p = listA.Concat(listB);
var k = listA.Concat(item);
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MySQL JOIN the most recent row only?
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You may want to try the following:
SELECT CONCAT(title, ' ', forename, ' ', surname) AS name
FROM customer c
JOIN (
SELECT MAX(id) max_id, customer_id
FROM customer_data
GROUP BY customer_id
) c...
In MySQL, can I copy one row to insert into the same table?
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SET @temptable = '_duplicate_temp_table';
SET @sql_text = CONCAT('CREATE TABLE ', @temptable, ' LIKE ', copytable);
PREPARE stmt FROM @sql_text;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
SET @sql_text = CONCAT('INSERT INTO ', @temptable, ' SELECT * FROM ...
How is null + true a string?
...e compiler, it's actually able to compile the above as:
string x = string.Concat(a, b, c, d);
which can create just a single string of exactly the right length, copying all the data exactly once. Nice.
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Create JSON object dynamically via JavaScript (Without concate strings)
...estions%2f16507222%2fcreate-json-object-dynamically-via-javascript-without-concate-strings%23new-answer', 'question_page');
}
);
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Name
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When is it better to use String.Format vs string concatenation?
...rmance hit, but to be honest it'll be minimal if present at all - and this concatenation version doesn't need to parse the format string.
Format strings are great for purposes of localisation etc, but in a case like this concatenation is simpler and works just as well.
With C# 6
String interpolat...
Are there pronounceable names for common Haskell operators? [closed]
...lt;|> or / alternative expr <|> term: "expr or term"
++ concat / plus / append
[] empty list
: cons
:: of type / as f x :: Int: f x of type Int
\ lambda
@ as go ll@(l:ls): go ll as l cons ls
~ lazy go ~(a,b): go la...
Merge 2 arrays of objects
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same result as the much simpler: arr1 = arr1.concat(arr2)
– keithpjolley
Nov 1 '16 at 14:55
9
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How do I combine two data frames?
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You can also use pd.concat, which is particularly helpful when you are joining more than two dataframes:
bigdata = pd.concat([data1, data2], ignore_index=True, sort=False)
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How do I kill all the processes in Mysql “show processlist”?
...n saves time. Do it in MySql itself:
Run these commands
mysql> select concat('KILL ',id,';') from information_schema.processlist
where user='root' and time > 200 into outfile '/tmp/a.txt';
mysql> source /tmp/a.txt;
Reference
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if you do not want to store in f...