# VOLATILE_SQL

> an SQL asset uses a value that changes on every run (warning)

**Warning** · category **warning** (nothing is blocked; the command still did its work) · exit **0** (ok)

An SQL asset uses a value that changes on every run (warning).

now(), current_date, current_timestamp, random(), gen_random_uuid() and similar functions give a new value each
time they run. An SQL asset is rebuilt only when an input or its SQL changes, so its table keeps the values of
its last rebuild: an "age in days" computed from current_date is wrong from the next day on, until something
else causes a rebuild.

What to do:
- Compute such columns when the table is read instead, in croft query or in the app's query:
  croft query "select \*, current_date - created_at::DATE AS age_days from open_issues".
- Keep it if a build-time value is what you want (a "built at" column); the warning then stays as a reminder.

The same page is in the CLI: `croft docs VOLATILE_SQL`.

Source: https://croft.zabaca.com/docs/reference/errors/volatile-sql/