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Hope this helps you, this is tested for me on PostgreSQL but may not work so well on MySQL. I've had to write similar queries in the past.

I'm assuming that the custom fields are for issues, not projects or something. You'll need to look up the custom field values from the Redmine admin menu for each of your two custom fields, and replace @2@ and @80@ with these ids. The dates can be changed in the query.

You'll most likely want to use ISO date format.

<pre><code class="sql">
SELECT issues.id
,trackers.name as "tracker"
,issues.subject
,authors.login as "author"
,assignees.login as "assignee"
,issues.created_on
,issues.start_date
,issues.closed_on
,issue_statuses.name as "status"
,custom1.value as "custom_1"
,custom2.value as "custom_2"
,issue_categories.name as "category"
,enumerations.name as "priority"
FROM issues
LEFT JOIN trackers
ON trackers.id = issues.tracker_id
LEFT JOIN users authors
ON authors.id = issues.author_id
LEFT JOIN users assignees
ON assignees.id = issues.assigned_to_id
LEFT JOIN enumerations
ON enumerations.id = issues.priority_id
AND enumerations.type = 'IssuePriority'
LEFT JOIN issue_statuses ON issue_statuses.id = issues.status_id
LEFT JOIN custom_values custom1
ON custom1.customized_id = issues.id
AND custom1.customized_type = 'Issue'
LEFT JOIN custom_values custom2
ON custom2.customized_id = issues.id
AND custom2.customized_type = 'Issue'
LEFT JOIN issue_categories
ON issue_categories.id = issues.category_id
WHERE issues.id IS NOT NULL
AND issues.start_date BETWEEN '2016-04-01' AND '2018-01-03'
AND custom1.custom_field_id = '2'
AND custom2.custom_field_id = '80'
GROUP BY issues.id, trackers.name, authors.login, assignees.login, custom1.value, custom2.value, issue_statuses.name, enumerations.name, issue_categories.name
</code></pre>
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