def add_limit_offset!(sql, options)
if options[:limit] and options[:offset]
total_rows = @connection.select_all("SELECT count(*) as TotalRows from (#{sql.gsub(/\bSELECT(\s+DISTINCT)?\b/i, "SELECT#{$1} TOP 1000000000")}) tally")[0][:TotalRows].to_i
if (options[:limit] + options[:offset]) >= total_rows
options[:limit] = (total_rows - options[:offset] >= 0) ? (total_rows - options[:offset]) : 0
end
sql.sub!(/^\s*SELECT(\s+DISTINCT)?/i, "SELECT * FROM (SELECT TOP #{options[:limit]} * FROM (SELECT#{$1} TOP #{options[:limit] + options[:offset]} ")
sql << ") AS tmp1"
if options[:order]
options[:order] = options[:order].split(',').map do |field|
parts = field.split(" ")
tc = parts[0]
if sql =~ /\.\[/ and tc =~ /\./
tc.gsub!(/\./, '\\.\\[')
tc << '\\]'
end
if sql =~ /#{tc} AS (t\d_r\d\d?)/
parts[0] = $1
elsif parts[0] =~ /\w+\.(\w+)/
parts[0] = $1
end
parts.join(' ')
end.join(', ')
sql << " ORDER BY #{change_order_direction(options[:order])}) AS tmp2 ORDER BY #{options[:order]}"
else
sql << " ) AS tmp2"
end
elsif sql !~ /^\s*SELECT (@@|COUNT\()/i
sql.sub!(/^\s*SELECT(\s+DISTINCT)?/i) do
"SELECT#{$1} TOP #{options[:limit]}"
end unless options[:limit].nil?
end
end