Question

我正在使用Sequelize，我一直遇到问题需要获得列的MAX

var userId = req.body.userId;
Sensor.findAll(
{
    where : {
        userId : userId
    }, 
    attributes: [
        sequelize.fn('MAX', sequelize.literal('temperature'))
    ],
    include: [{
        model: models.Temperature
    }]
}).then(function(sensor_result) {
    res.status(200).json({ status:"success", data: sensor_result });
}).catch(function(error) {
    console.log(error);
    res.status(409).json({ status:"error", data: null, message:"Something went wrong, please try again." });
})

这样可行，但如果我将温度列更改为cratedAt列，则会导致出现问题＆＃34; ER_NON_UNIQ_ERROR：Column＆＃39; createdAt＆＃39;在字段列表中是不明确的＆＃34;

var userId = req.body.userId;
Sensor.findAll(
{
    where : {
        userId : userId
    }, 
    attributes: [
        sequelize.fn('MAX', sequelize.literal('createdAt'))
    ],
    include: [{
        model: models.Temperature
    }]
}).then(function(sensor_result) {
    res.status(200).json({ status:"success", data: sensor_result });
}).catch(function(error) {
    console.log(error);
    res.status(409).json({ status:"error", data: null, message:"Something went wrong, please try again." });
})

临时解决方案就是这个，但它根本没有效率

Sensor.findAll(
{
    where : {
        userId : userId
    }, 
    include: [{
        model: models.Temperature,
        order: [['createdAt', 'DESC']],
        limit: 1
    }]
}).then(function(sensor_result) {
    res.status(200).json({ status:"success", data: sensor_result });
}).catch(function(error) {
    res.status(409).json({ status:"error", data: null, message:"Something went wrong, please try again." });
})

所以我想知道是否有任何选项可以获取createdAt列的MAX值

如何使用Sequelize获取MAX列

0 个答案: