Question

我想找到本周和select dayofweek(datetime), avg(value) from Temperatures where week(datetime) = week(now()) group by dayofweek(datetime);分组的平均值，所以我写了这个sql，sql运行良好，但我如何才能通过sequelize达到同样的目的。

Temperatures

这是我的| field | type | |----------|-------------| | uuid | char(36) | | value | float | | datetime | datetime |表： where

我已经阅读了续集的文档，但似乎没有明确解释如何在where: { [Sequelize.Op.eq]: [ sequelize.fn('week', Temperature.sequelize.fn('now')), sequelize.fn('week', Temperature.sequelize.col('datetime')), ] },句后使用函数，条件是函数而不是字段。

我已经尝试了，但它不起作用

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感谢您的帮助！

Answer 1

您可以使用sequelize.fn，例如：

[sequelize.fn('dayofweek', sequelize.col('datetime')), 'datetime']

有关详情 even when new blocks are created

Answer 2

最后，我发现以下方法效果很好

return Temperature.findAll({
  attributes: [
    [Temperature.sequelize.fn('dayofweek', Temperature.sequelize.col('datetime')), 'dayofweek'],
    [Temperature.sequelize.fn('AVG', Temperature.sequelize.col('value')), 'value'],
  ],
  where: sequelize.where(sequelize.fn('week', Temperature.sequelize.fn('now')), sequelize.fn('week', Temperature.sequelize.col('datetime'))),
  group: sequelize.fn('dayofweek', Temperature.sequelize.col('datetime')),
});

如果我需要更多的条件过滤器，只需添加一个[Op.and]运算符

return Temperature.findAll({
  attributes: [
    [Temperature.sequelize.fn('dayofweek', Temperature.sequelize.col('datetime')), 'dayofweek'],
    [Temperature.sequelize.fn('AVG', Temperature.sequelize.col('value')), 'value'],
  ],
  where: {
    [Sequelize.Op.and]: [
      sequelize.where(sequelize.fn('week', Temperature.sequelize.fn('now')), sequelize.fn('week', Temperature.sequelize.col('datetime'))),
    ]
  },
  group: sequelize.fn('dayofweek', Temperature.sequelize.col('datetime')),
});

这里是sql生成的

SELECT dayofweek(`datetime`) AS `dayofweek`, AVG(`value`) AS `value` FROM `Temperatures` AS `Temperature` WHERE (week(now())=week(`datetime`)) GROUP BY dayofweek(`datetime`);

如何通过sequelize在句子中使用db函数

2 个答案: