用Sequelize计算关联条目

使用

findAll()

include()

sequelize.fn()

COUNT

Location.findAll({    attributes: {         include: [[Sequelize.fn("COUNT", Sequelize.col("sensors.id")), "sensorCount"]]     },    include: [{        model: Sensor, attributes: []    }]});

或者，您可能还需要添加一个

group

Location.findAll({    attributes: {         include: [[Sequelize.fn("COUNT", Sequelize.col("sensors.id")), "sensorCount"]]     },    include: [{        model: Sensor, attributes: []    }],    group: ['Location.id']})