mysql - Sequelize 'hasMany' 关联(模型)在查询执行中的属性计数

Question

Sequelize 版本:4.22.6，MySql版本:5.7.8我想在查询执行中'hasMany' associated(CompanyUser) 在属性中计数(在 _user_count_ 的位置)

/**
* Company user associate with Company with belongsTo relation
*/
`CompanyUser.belongsTo(Company, { foreignKey: 'company_id', targetKey: 'id'});`

/**
* Company  associate with Company user with hasMany relation
*/
`Company.hasMany(CompanyUser, { foreignKey: 'company_id', sourceKey: 'id'});`

`return Company.findAll({
    attributes: [
        'id', 'title', 'is_enabled', '_user_count_'
    ]
    include: [
        {
            model: sqConn.CompanyUser,
            attributes: ['id'],
        },
        {
            model: sqConn.CompanyLogo,
            attributes:['file_object'],
        }
    ],
}).then(function(model) {
    return sequelize.Promise.resolve(model);
}).catch(function(err) {
    return sequelize.Promise.reject(err);
});`

使用左连接的简单 MySQL 查询工作正常并给出计数。

Answer 1

您可以使用 sequelize.fn ，尝试运行以下查询:

Company.findAll({
    attributes: [
        'id', 'title', 'is_enabled',
        [sequelize.fn('count', sequelize.col('company_users.id')) ,'user_count'] // <---- Here you will get the total count of user
    ],
    include: [
        {
            model: sqConn.CompanyUser,
            attributes: [] // <----- Make sure , this should be empty
        }
    ],
    group: ['companies.id'] // <---- You might require this one also
}).then(data => { 
    console.log(data); // <---- Check the output
})