Helper bash script for AWS command line DockerDB scan counts

dyncount

#!/bin/bash

case $1 in
help)
  echo 'usage: dyncount <table> <column> <"="|"<>"|"<"|"<="|">"|">="> <type> <value>';
  echo 'example: ./dyncount user firstName "=" S Gary';
  echo '';
  echo 'usage: dyncount <table> <column> <attribute_exists|attribute_not_exists>';
  echo 'example: ./dyncount user firstName attribute_exists';
  echo '';
  echo 'usage: dyncount <table> <column> <begins_with|contains|attribute_type> <string>';
  echo 'example: ./dyncount user firstName contains Gary';
  echo '';
  echo 'usage: dyncount <table> <column> BETWEEN <type> <value1> AND <value2>';
  echo 'example: ./dyncount term sectionCount BETWEEN N 0 AND 5';
  ;;
esac;

case $3 in
"="|"<>"|"<"|"<="|">"|">=")
  aws dynamodb scan --table-name $1 --select "COUNT" --filter-expression "$2 $3 :a" --expression-attribute-values "{\":a\" : {\"$4\" : \"$5\"}}";
  ;;
attribute_exists|attribute_not_exists)
  aws dynamodb scan --table-name $1 --select "COUNT" --filter-expression "$3($2)";
  ;;
begins_with|contains|attribute_type)
  aws dynamodb scan --table-name $1 --select "COUNT" --filter-expression "$3($2, :a)" --expression-attribute-values "{\":a\" : {\"S\" : \"$4\"}}";
  ;;
BETWEEN)
  aws dynamodb scan --table-name $1 --select "COUNT" --filter-expression "$2 BETWEEN :a AND :b" --expression-attribute-values "{\":a\" : {\"$4\" : \"$5\"}, \":b\" : {\"$4\" : \"$7\"}}";
  ;;
esac;

# other conditionals that would be harder to script for so I'm not soing it right now
#     | operand BETWEEN operand AND operand
#     | operand IN ( operand (',' operand (, ...) ))
#     | condition AND condition
#     | condition OR condition
#     | NOT condition
#     | ( condition )