I have a daily csv file with thousands of rows.
I have been asked to concatenate two columns, then insert a new column when a value in a given column matches a table from another file. Empty values are to be expected.
simplifying the data (column 3 is concatenated):
daily.csv
HVDS,1810,HVDS_1810,"match value",xxxxx
HVRS,5230,HVRS_5230,"match value",xxxxx
WPHV,0,WPHV_0000,"no match",xxxxx
reference file has two columns, searching $1 and inserting $2 above
ref.csv
HVDS_1810,dfTVfsd
HVRS_5230,UtsfeOO
WPHV_4242,BBnnstd
Just some ideas needed on where to begin.