Remove unnecessary things for draw.io SQL import from mysqldump --no-data

schema4erb.rb

lines = \
    STDIN.readlines.reject{|x| x =~ /\A--/}.
    reject{|x| x =~ %r{\A\s*/\*.+\*/;\s\z}}.
    reject{|x| x =~ /\A\s*DROP TABLE.+;\s*\z/}.
    reject{|x| x =~ /\A\s*UNIQUE KEY .+,\s*\z/}.
    reject{|x| x =~ /\A\s*KEY .+,\s*\z/}.
    reject{|x| x =~ /\A\s*CONSTRAINT .+,?\s*\z/}
lines = lines.map{|x| x.sub(/\A([^\`]*)\`([^\`]+)\`(.+)/, '\1\2\3') }
text = lines.join
text.gsub!(/\) ENGINE=InnoDB .+\;/, ")")
text.gsub!(/,\n\)/m, "\n)")

puts text