mysql - 如何将行转换为基于列的重复数据？

Question

我正在尝试获取如下所示的数据集：

并将记录转换为这种格式：

生成的格式将有两列，一列用于旧列名，一列用于值。如果有 10,000 行，那么应该有 10,000 组新格式的数据。

我对所有不同的方法持开放态度，excel 公式、sql (mysql) 或直接 ruby​​ 代码也适用于我。解决这个问题的最佳方法是什么？

Answer 1

您可以在数据左侧添加一个 ID 列并使用反向数据透视表方法。

• 按 Alt+D+P 访问数据透视表向导，步骤如下：

  1.  Multiple Consolidation Ranges
  2a. I will create the page fields
  2b. Range: eg. sheet1!A1:A4 
      How Many Page Fields: 0
  3.  Existing Worksheet: H1
  

• 在数据透视表中：

  Uncheck Row and Column from the Field List
  Double-Click the Grand Total as shown
  

Answer 2

只是为了好玩：

# Input file format is tab separated values

# name  search_term address code
# Jim jim jim_address 123
# Bob bob bob_address 124
# Lisa  lisa  lisa_address  126
# Mona  mona  mona_address  129


infile = File.open("inputfile.tsv")

headers = infile.readline.strip.split("\t")
puts headers.inspect
of = File.new("outputfile.tsv","w")
infile.each_line do |line|
  row = line.split("\t")
  headers.each_with_index do |key, index|
    of.puts "#{key}\t#{row[index]}"
  end
end

of.close



# A nicer way, on my machine it does 1.6M rows in about 17 sec

File.open("inputfile.tsv") do | in_file |
  headers = in_file.readline.strip.split("\t")
  File.open("outputfile.tsv","w") do | out_file |
    in_file.each_line do | line |
      row = line.split("\t")
      headers.each_with_index do | key, index | 
        out_file << key << "\t" << row[index]
      end
    end 
  end
end

Answer 3

destination = File.open(dir, 'a') do |d|   #choose the destination file and open it

    source = File.open(dir , 'r+') do |s|  #choose the source file and open it
      headers = s.readline.strip.split("\t")  #grab the first row of the source file to use as headers
      s.each do |line| #interate over each line from the source

        currentLine = line.strip.split("\t") #create an array from the current line
           count = 0   #track the count of each array index
        currentLine.each do |c| #iterate over each cell of the currentline
              finalNewLine = '"' + "#{headers[count]}" + '"' + "\t" + '"' + "#{currentLine[count]}" + '"' + "\n" #build each new line as one big string
          d.write(finalNewLine) #write final line to the destination file.
          count += 1 #increment the count to work on the next cell in the line
        end

      end
  end

end