我正在尝试在 spiceworks 中创建一个需要上个月数据的报告。我在这里看到了这个链接：Query last day, last week, last month SQLite但是月份示例只返回当前月份。我需要上个月。该报告将在每个月的第一天运行，这是我迄今为止所拥有的：
SELECT a.id as "Ticket #", c.first_name||' '|| c.last_name as "Created By", a.c_location as "Location",
a.c_hud as "HUD", a.closed_at as "Closed", a.c_urgency as "Urgency", a.category as "Category",
a.summary as "Summary", SUM(b.time_spent)/3600.0 as "Time Spent (Hrs)",
d.price*d.quantity as "Purchases"
FROM tickets a
LEFT OUTER JOIN ticket_work b ON a.id = b.ticket_id
LEFT OUTER JOIN purchase_list_items d on a.id = d.ticket_id
JOIN users c ON a.created_by = c.id
WHERE closed_at BETWEEN datetime('now', 'start of month') AND datetime('now','localtime')
GROUP BY a.id
ORDER BY c_location;
一旦我得到正确的数据集，我必须将整数类型的总 b.time_spent 字段转换为小时格式。因此，如果花费的时间总和为 33600，我需要将输出转换为 9.33，而不是当前给出的 9。它目前只给我任何帮助将不胜感激。