def rename_column_sql(table_name, column_name, new_column_name)
options = {}
if column = columns(table_name).find { |c| c.name == column_name.to_s }
options[:default] = column.default
options[:null] = column.null
else
raise ActiveRecordError, "No such column: #{table_name}.#{column_name}"
end
current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'")["Type"]
rename_column_sql = "CHANGE #{quote_column_name(column_name)} #{quote_column_name(new_column_name)} #{current_type}"
add_column_options!(rename_column_sql, options)
rename_column_sql
end