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How to import load a .sql or .csv file into SQLite?
...test.csv line 2: expected 2 columns of data but found 3
It seems we must transform the csv into a list of Insert statements, or perhaps a different delimiter will work.
Over at SuperUser I saw a suggestion to use LogParser to deal with csv files, I'm going to look into that.
...
How to drop columns using Rails migration
...l forth you can give options. It is a bit hidden in the section 'Available transformations' on the documentation .
class RemoveFieldFromTableName < ActiveRecord::Migration
def change
remove_column :table_name, :field_name, :data_type, {}
end
end
...
How to do what head, tail, more, less, sed do in Powershell? [closed]
... in Where-Object (or via Foreach-Object and some state for ranges). Other, transforming, operations can be done with Select-Object and Foreach-Object.
However as PowerShell passes (.NET) objects – with all their typed structure, eg. dates remain DateTime instances – rather than just strings, wh...
Website screenshots
...via ajax and save it as a jpg.
EDIT: You can use the imagemagick tool for transforming pdf to png. My version of wkhtmltopdf does not support images. E.g. convert html.pdf -append html.png.
EDIT: This small shell script gives a simple / but working usage example on linux with php5-cli and the tool...
MySQL case insensitive select
...erstand collations and indexes and configure those properly - using string transformations like LOWER() or an arbitrary COLLATE clause can completely bypass an index, and over time, as your table grows, this can have drastic performance implications. Likely these are usernames you're looking up? Use...
What's the correct way to convert bytes to a hex string in Python 3?
...
Python has bytes-to-bytes standard codecs that perform convenient transformations like quoted-printable (fits into 7bits ascii), base64 (fits into alphanumerics), hex escaping, gzip and bz2 compression. In Python 2, you could do:
b'foo'.encode('hex')
In Python 3, str.encode / bytes.deco...
How do I delete rows in a data frame?
...= myData[!myData$A > 4,] # equal to myData[myData$A <= 4,]
You can transform a boolean vector to a vector of indices:
row_to_keep = which(myData$A > 4)
Finally, a very neat trick is that you can use this kind of subsetting not only for extraction, but also for assignment:
myData$A[myD...
If my interface must return Task what is the best way to have a no-operation implementation?
... would be more efficient". Making a method async instructs the compiler to transform it into a state-machine. It will also create a new task each time you call it. Returning an already completed task would be clearer and more performant.
– i3arnon
Aug 3 '15 at ...
Convert string to binary in python
...a byte array because it makes low level function calls instead of manually transforming every character to an integer, and then converting that integer into its binary value.
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C++ 线程安全的单例模式 - C/C++ - 清泛网 - 专注C/C++及内核技术
C++ 线程安全的单例模式一、懒汉模式：即第一次调用该类实例的时候才产生一个新的该类实例，并在以后仅返回此实例。需要用锁，来保证其线程安全性：原因：多个线程 一、懒汉模式：即第一次调用该类实例的时候才产生...