How do you add comments to MySQL queries, so they show in logs?

Question

I want to be able to add a little note, at the beginning of each query, so when I see it in the processlist, or "mytop", I can tell where it’s running. Is something like this possible?

Accepted Answer

I am not sure this would work, but it is worth trying.

Simply add `"/* some comment or tag */ "` before whatever SQL query is sent normally.

It is possible that MySQL server will remove this comment as part of its query analysis/preparation, but it may just leave it as well, so it shows as such in logs and other monitoring tools.

In case the comments get stripped away, and assuming SELECT queries, a slight variation on the above would be to add a calculated column as the first thing after SELECT, something like

```
SELECT IF('some comment/tag' = '', 1, 0) AS BogusMarker, here-start-the-original-select-list
-- or
SELECT 'some [short] comment/tag' AS QueryID, here-start-the-original-select-list
```

This approach has the drawback of introducing an extra column value, with each of the results row. The latter form, actually uses the "comment/tag" value as this value, which may be helpful for debugging purposes.

How do you add comments to MySQL queries, so they show in logs?

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