在数据中只有月份和年份的 mongodb 中字符串的日期时间

Mongo要求"日期"部分完全存在，这意味着它预计至少有一年、一个月和一天.

因此，您可以在字符串中填充01并提供格式选项:

db.collection.aggregate([
  {
    $addFields: {
      date: {
        "$dateFromString": {
          "dateString": {
            "$concat": [
              "01",
              "$date"
            ]
          },
          "format": "%d%m%Y"
        }
      }
    }
  }
])

Mongo Playground个

或者使用$dateFromParts:

db.collection.aggregate([
  {
    $addFields: {
      date: {
        "$dateFromParts": {
          year: {
            "$toInt": {
              "$substr": [
                "$date",
                2,
                4
              ]
            }
          },
          month: {
            $toInt: {
              $substr: [
                "$date",
                0,
                2
              ]
            }
          }
        }
      }
    }
  }
])

Mongo Playground个

奖励-此要求在文档中没有明确说明，但可以在源代码中找到:

if (s->time->y != TIMELIB_UNSET && s->time->m != TIMELIB_UNSET &&
    s->time->d != TIMELIB_UNSET &&
    !timelib_valid_date( s->time->y, s->time->m, s->time->d)) {
    add_pbf_warning(s, TIMELIB_WARN_INVALID_DATE, "The parsed date was invalid", string, ptr);
}