title: What's the best way to fuzzy join (multiple) dataframes by multiple columns?
body: <p>I need to join multiple data frames, but given that the experiment ran online and participants were often sloppy when entering their ID, I added redundancy. The also had to add letters of their parents name and their zip code. I checked manually (a bit) and there's a good amount of errors. Now I need to merge by multiple columns instead of just the participant ID.</p>
  
  <p>I figured that using the fuzzyjoin package makes most sense, but I'm not sure how to go about merging multiple data frames by multiple columns each? Should I just fuzzy_right_join one data frame at a time? I have 6 in total.</p>
  
  <p>Many thanks!</p>
  
  <p>Here's a snippet of a few to give you an idea:</p>
  
  <pre><code>structure(list(participant = c("107", "110", "111", "116", "140", 
  "141"), Vorname_Mutter_2_Buchstaben = c("th", "ro", "mo", "es", 
  "br", "gl"), Vorname_Vater_2_Buchstaben = c("al", "ha", "wa", 
  "th", "he", "re"), PLZ_letzte_2_Ziffern = c(28L, 4L, 23L, 10L, 
  15L, 90L), date = structure(c(1587307867.619, 1586435099.121, 
  1586424077.282, 1587733915.271, 1586794445.732, 1586896454.853
  ), tzone = "UTC", class = c("POSIXct", "POSIXt")), mean_RT = c(0.658042654028436, 
  0.612637426900585, 0.721700276752767, 0.532778303249097, 0.448516151241535, 
  0.59286090389016)), row.names = c(NA, -6L), class = c("tbl_df", 
  "tbl", "data.frame"))
  
  structure(list(participant = c("001", "240", "242", "243", "244", 
  "245"), Vorname_Mutter_2_Buchstaben = c("ma", "el", "ur", "ka", 
  "ja", "la"), Vorname_Vater_2_Buchstaben = c("he", "ma", "re", 
  "jo", "fe", "ab"), PLZ_letzte_2_Ziffern = c(27L, 3L, 3L, 0L, 
  47L, 66L), date = structure(c(1588072799.367, 1586624239.667, 
  1586260007.882, 1586712365.514, 1586275669.545, 1586696526.84
  ), tzone = "UTC", class = c("POSIXct", "POSIXt")), RT_moving_variance = c(6258.46945397108, 
  5172.19983111429, 5032.90280000055, 5906.46678346693, 18694.9916770777, 
  7065.17254133398)), row.names = c(NA, -6L), class = c("tbl_df", 
  "tbl", "data.frame"))
  
  structure(list(participant = c("1", "105", "107", "110", "111", 
  "116"), Vorname_Mutter_2_Buchstaben = c("ma", "an", "th", "ro", 
  "mo", "es"), Vorname_Vater_2_Buchstaben = c("he", "ce", "al", 
  "ha", "wa", "th"), PLZ_letzte_2_Ziffern = c("27", "0", "28", 
  "4", "23", "10"), date = structure(c(1588071580.734, 1587402995.471, 
  1587306792.774, 1586434189.309, 1586422686.217, 1587732745.487
  ), tzone = "UTC", class = c("POSIXct", "POSIXt")), on_task_mean = c(1, 
  1, 2, 2, 1, 1)), row.names = c(NA, -6L), class = c("tbl_df", 
  "tbl", "data.frame"))
  
  structure(list(participant = c("270", "494", "261", "171", "177", 
  "323"), Vorname_Mutter_2_Buchstaben = c("se", "br", "ma", "do", 
  "ir", "li"), Vorname_Vater_2_Buchstaben = c("na", "th", "ar", 
  "sv", "re", "ur"), PLZ_letzte_2_Ziffern = c("02", "38", "67", 
  "03", "10", "07"), date = structure(c(1586187946.415, 1586212359.648, 
  1586251863.165, 1586255167.624, 1586255616.763, 1586258326.743
  ), tzone = "UTC", class = c("POSIXct", "POSIXt")), Alter = c(26, 
  27, 21, 28, 25, 22)), row.names = c(NA, -6L), class = c("tbl_df", 
  "tbl", "data.frame"))
  </code></pre>