#!/bin/bash

# AMPY script to drop/recreate a subset of the ampy tables
# John Bonifas
# last updated 07-10-20
# https://docs.cloudera.com/documentation/enterprise/5-9-x/topics/impala_shell_options.html

let "var=0";
TARGETFOLDER=/development/etl/source/ampy;
echo '' > dropandrecreate_errors.txt;
echo '' > dropandrecreate_log.txt;

# the input flat file MUST be run through the dos2unix utility first or it won't work here,
# due to the carriage return / linefeeds in Windows
mapfile -t OUTPUTTABLES < <(cat tablenamesNeedDropRecreate.csv)

for TABLENAME in ${OUTPUTTABLES[@]}
do

  let "VAR++";
  echo Number $VAR ... Working with table: $TABLENAME;

  CREATEHQLFILE=$TARGETFOLDER/$TABLENAME/create_table_ampy-$TABLENAME.hql;
  CREATEQUERY=`hdfs dfs -cat $CREATEHQLFILE`;
  # https://stackoverflow.com/questions/40714970/escaping-forward-slashes-in-sed-command/40715028
  # you can use | instead of / to avoid having to escape out forward slashes
  RUNQUERY=`echo "$CREATEQUERY" | sed 's|${environment}|dev_|g;s|${directory}|development/data|g;s|varchar(8000)|string|g'`;

  #DROP AND RECREATE
  impala-shell -k -i srphdw010 --quiet -q "use dev_ampy;drop table if exists $TABLENAME purge;" &&
  echo "$RUNQUERY" | impala-shell -k -i srphdw010 --quiet -f - 2>>dropandrecreate_errors.txt;
  echo -e dropped and recreated $TABLENAME. "\n"  | tee -a dropandrecreate_log.txt;
  echo -e "\n";

done