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Large, persistent DataFrame in pandas
...o read the file in smaller pieces (use iterator=True, chunksize=1000) then concatenate then with pd.concat. The problem comes in when you pull the entire text file into memory in one big slurp.
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Copy array items into another array
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Use the concat function, like so:
var arrayA = [1, 2];
var arrayB = [3, 4];
var newArray = arrayA.concat(arrayB);
The value of newArray will be [1, 2, 3, 4] (arrayA and arrayB remain unchanged; concat creates and returns a new arr...
How do I use the CONCAT function in SQL Server 2008 R2?
I was looking for a CONCAT function in SQL Server 2008 R2. I found the link for this function . But when I use this function, it gives the following error:
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How can I combine multiple rows into a comma-delimited list in Oracle? [duplicate]
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Just make sure your concatenated results don't exceed the VARCHAR2 max length limit of your oracle database (most likely 4000 bytes) otherwise you will run into ORA-01489 result of string concatenation is too long.
– JanM
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How to flatten tree via LINQ?
...rable<MyNode> e) =>
e.SelectMany(c => Flatten(c.Elements)).Concat(new[] { e });
You can then filter by group using Where(...).
To earn some "points for style", convert Flatten to an extension function in a static class.
public static IEnumerable<MyNode> Flatten(this IEnumer...
Increment value in mysql update query
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Concatenating user data as demonstrated into an SQL query is a major SQL injection risk.
– trognanders
Nov 6 '15 at 1:20
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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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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 ...
IEnumerable to string [duplicate]
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You can use String.Concat().
var allowedString = String.Concat(
inputString.Where(c => allowedChars.Contains(c))
);
Caveat: This approach will have some performance implications. String.Concat doesn't special case collections of char...
GROUP BY to combine/concat a column [duplicate]
...Nice! To elaborate: you are using STUFF() to remove the first comma of the concatenated PageUrl string. The PageUrl string itself is created by using FOR XML PATH(), with an empty path, to concatenate the retrieved PageUrls. Pretty clever :) Some sources: STUFF(): msdn.microsoft.com/en-us/library/ms...