Create dropdown filter options for a column when you create a .csv file from php

Does anybody know how to create drop down/ filter options for a particular column when you create a .csv file with php. I am gen开发者_C百科erating a .csv template and want to give the option of choosing only the filter values as cell data for that column.

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CSV files are plain text files containing rows of data, each column separated by a comma (or other character).

The functionality you describe isn't part of CSV.

Creating a drop-down menu to filter a column would be a function of something viewing the data in the CSV, such as a spreadsheet program. Take a look at PEAR's Spreadsheet_Excel_Writer, it might let you create a spreadsheet with a filter dropdown.