Question

我与Company和CompanyType之间有很多关系

我想获取一个列表，其中仅列出CompanyType.Name为“ Client”的公司。即一个clientCompanyList。

如何在linq中做到这一点？

我基本上想在linq中做以下事情

var clientCompanies = db.Companies.SqlQuery(@"SELECT  c.*
FROM    Companies AS c
JOIN    CompanyTypeCompanies AS ctc ON ctc.Company_ID = c.ID
JOIN    CompanyTypes AS ct ON ctc.CompanyType_ID = ct.ID
WHERE   ct.Name = 'Client'").ToList();

Answer 1

如果表之间具有正确的外键关系，则可以使用include语句

var clientCompanies = db.CompanyTypes
.Where(ct => ct.Name == "Client").Include(ct => ct.CompanyTypeCompanies).Include(ct => ct.Companies).Select(ct => ct.Companies).ToList();

在启动课程中

public void ConfigureServices(IServiceCollection services)
{
    ...

    services.AddMvc()
        .AddJsonOptions(
            options => options.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore
        );

    ...
}

MVC多对多获取仅在代码中具有某种类型的实体

1 个答案: