sql - 使用 sequelize 使用 where 查询编码计数

Question

我想通过使用 sequelize 和 node.js 将这个查询更改为代码取决于在哪里

select COUNT(gender) as genderCount from customers where gender = "male"

但我不知道如何添加
这个原始代码:

 Customer.findAll({
      attributes: { 
        include: [[Sequelize.fn("COUNT", Sequelize.col("gender")), "genderCount"]]  }
      }).then(data => {
      res.send(data)
    })

Answer 1

对于 "sequelize": "^5.21.3" :
选项1。

const customers = await Customer.findAll({
    attributes: [[Sequelize.fn('COUNT', Sequelize.col('gender')), 'genderCount']],
    where: {
      gender: 'male',
    },
    raw: true,
});

执行结果:

Executing (default): SELECT COUNT("gender") AS "genderCount" FROM "customers" AS "Customer" WHERE "Customer"."gender" = 'male';
[ { genderCount: '3' } ]

选项 2. 您可以使用 Model.count() 。

Count the number of records matching the provided where clause.

const customers = await Customer.count({ col: 'gender', where: { gender: 'male' } });

执行结果:

Executing (default): SELECT count("gender") AS "count" FROM "customers" AS "Customer" WHERE "Customer"."gender" = 'male';

以上示例基于数据库中的数据记录: