Sequelize 'hasMany' 关联(模型)计数在查询执行中的属性
本教程将介绍Sequelize 'hasMany' 关联(模型)计数在查询执行中的属性的处理方法,这篇教程是从别的地方看到的,然后加了一些国外程序员的疑问与解答,希望能对你有所帮助,好了,下面开始学习吧。
问题描述
续集版本:4.22.6,MySql版本:5.7.8我想在查询执行中将 'hasMany' 关联(CompanyUser)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);
});`
带有左连接的简单 MySQL 查询可以正常工作并给出计数.
推荐答案
你可以使用 sequelize.fn
,尝试运行下面的查询:
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
})
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