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schema builder laravel migrations unique on two columns
How can I set a unique constraints on two columns?
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Label encoding across multiple columns in scikit-learn
I'm trying to use scikit-learn's LabelEncoder to encode a pandas DataFrame of string labels. As the dataframe has many (50+) columns, I want to avoid creating a LabelEncoder object for each column; I'd rather just have one big LabelEncoder objects that works across all my columns of data. ...
How can I alter a primary key constraint using SQL syntax?
I have a table that is missing a column in its primary key constraint. Instead of editing it through SQL Server, I want to put this in a script to add it as part of our update scripts.
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What is the maximum characters for the NVARCHAR(MAX)?
I have declared a column of type NVARCHAR(MAX) in SQL Server 2008, what would be its exact maximum characters having the MAX as the length?
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SparseArray vs HashMap
I can think of several reasons why HashMap s with integer keys are much better than SparseArray s:
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List of standard lengths for database fields
I'm designing a database table and once again asking myself the same stupid question: How long should the firstname field be?
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How do you use “
I just finished reading about scoping in the R intro , and am very curious about the <<- assignment.
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how to “reimport” module to python then code be changed after import
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Best way to parse command line arguments in C#? [closed]
When building console applications that take parameters, you can use the arguments passed to Main(string[] args) .
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Convert an integer to a float number
How do I convert an integer value to float64 type?
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