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Only read selected columns
...from the data.table-package:
You can specify the desired columns with the select parameter from fread from the data.table package. You can specify the columns with a vector of column names or column numbers.
For the example dataset:
library(data.table)
dat <- fread("data.txt", select = c("Year...
TSQL Pivot without aggregate function
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yes, but why !!??
Select CustomerID,
Min(Case DBColumnName When 'FirstName' Then Data End) FirstName,
Min(Case DBColumnName When 'MiddleName' Then Data End) MiddleName,
Min(Case DBColumnName When 'LastName' Then Data End) LastNa...
PHP code to convert a MySQL query to CSV [closed]
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SELECT * INTO OUTFILE "c:/mydata.csv"
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
LINES TERMINATED BY "\n"
FROM my_table;
(the documentation for this is here: http://dev.mysql.com/doc/refman/5.0/en/select.html)
or:...
Android Spinner : Avoid onItemSelected calls during initialization
...droid application with a Spinner and a TextView . I want to display the selected item from the Spinner's drop down list in the TextView. I implemented the Spinner in the onCreate method so when I'm running the program, it shows a value in the TextView (before selecting an item from the drop d...
Bootstrap 3: Keep selected tab on page refresh
I am trying to keep selected tab active on refresh with Bootstrap 3 . Tried and checked with some question already been asked here but none of work for me. Don't know where I am wrong. Here is my code
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How do I compare two files using Eclipse? Is there any option provided by Eclipse?
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To compare two files in Eclipse, first select them in the Project Explorer / Package Explorer / Navigator with control-click. Now right-click on one of the files, and the following context menu will appear. Select Compare With / Each Other.
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Find value in an array
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Using Array#select will give you an array of elements that meet the criteria. But if you're looking for a way of getting the element out of the array that meets your criteria, Enumerable#detect would be a better way to go:
array = [1,2,...
Select last N rows from MySQL
I want to select last 50 rows from MySQL database within column named id which is primary key . Goal is that the rows should be sorted by id in ASC order, that’s why this query isn’t working
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Effect of NOLOCK hint in SELECT statements
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1) Yes, a select with NOLOCK will complete faster than a normal select.
2) Yes, a select with NOLOCK will allow other queries against the effected table to complete faster than a normal select.
Why would this be?
NOLOCK typically (...
get list of pandas dataframe columns based on data type
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If you are just selecting columns by data type, then this answer is obsolete. Use select_dtypes instead
– Ted Petrou
Nov 3 '17 at 16:58
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