无法将 SQL 查询转换为 Entity Framework Core

Posted 2023-03-29

【中文标题】无法将 SQL 查询转换为 Entity Framework Core

【英文标题】：Unable to convert SQL query to Entity Framework Core

【发布时间】：2020-07-18 01:19:42

【问题描述】：

我无法将我的 SQL 查询转换为 Entity Framework Core。

SQL 查询是：

select * 
from tests 
join TestParameters on (tests.Id = TestParameters.TestId) 
join PatientTests on (Tests.Id = PatientTests.TestId) 
where PatientId = 3

模型如下所示：

public class Tests

    [Key]
    public int Id  get; set; 

    [Required]
    [Display(Name = "Test Name")]
    public string TestName  get; set; 

    [Display(Name = "Short Name")]
    public string  ShortName  get; set; 

    [Display(Name="Technical Name")]
    public string  TechName  get; set; 

    [Required]
    [Display(Name ="Test Price")]
    public float TestPrice  get; set; 

    [Display(Name = "Sub Department")]
    public int SubDeptId  get; set; 

    [Display(Name = "Center")]
    public int CenterId  get; set; 

    public string Separate  get; set; 

    [Display(Name = "Sub Department")]
    [ForeignKey("SubDeptId")]
    //relation of departments table
    public virtual SubDepartments subDepartments  get; set; 

    [Display(Name = "Centers")]
    [ForeignKey("CenterId")]
    //relation of departments table
    public virtual Centers centers   get; set; 


public class TestParameter

    [Key]
    public int Id  get; set; 

    [Required]
    public string Categories  get; set; 

    [Required]
    [Display(Name = "Test Parameter Name")]
    public string ParameterName  get; set; 

    [Required]
    public string Unit  get; set; 

    [Display(Name ="Decimal Point")]
    public int DecimalPoint  get; set; 

    [Display(Name = "Help Value")]
    public string HelpValue  get; set; 

    [Display(Name = "Normal Range")]
    public string NormalRange  get; set; 

    public string Minimum  get; set; 

    public string Maximum  get; set; 

    [Display(Name="Test Footer")]
    public string TestFooter  get; set; 

    [Display(Name = "Tests Name")]
    public int TestId  get; set; 

    [ForeignKey("TestId")]
    //relation of departments table
    public virtual Tests Tests  get; set; 


public class PatientTest

    [Key]
    public int Id  get; set; 

    [Display(Name ="Patient Id")]
    public int PatientId  get; set; 

    [Display(Name ="Test Id")]
    public int TestId  get; set; 

    [Display(Name ="Doctor")]
    public int DoctorId  get; set; 

    [Display(Name="Center")]
    public int CenterId  get; set; 

    [Display(Name = "Test")]
    [ForeignKey("TestId")]
    //relation of Tests table
    public virtual Tests Tests  get; set; 

    [Display(Name = "Doctor Reference")]
    [ForeignKey("DoctorId")]
    //relation of Doctors table
    public virtual Doctors Doctors  get; set; 

    [Display(Name = "Center Reference")]
    [ForeignKey("CenterId")]
    //relation of Centers table
    public virtual Centers Centers  get; set; 

    [Display(Name = "Patient")]
    [ForeignKey("PatientId")]
    //relation of Patient table
    public virtual Patient Patient  get; set; 

PatientTests 包含患者、测试、测试参数的关系。

我尝试转换它，但它返回单个数据。

我的代码是：

var test = await _db.TestParameters
                    .Include(p => p.Tests)
                    .Where(p => p.Tests.Id == pttp.patient.Id)
                    .ToListAsync();

【问题讨论】：

当您使用导航属性时（因为您没有正确实现它），您不需要检查加入参数。所以.Where(p=>p.Tests.pttp.patient.Id==3)。我强烈推荐阅读本教程：entityframeworktutorial.net/efcore/…

【参考方案1】：

您可以将查询拆分为两个查询。

1) 选择患者测试

var patientTests = _db.PatientTests
    .Include(x => x.Test)
    .Where(x => x.PatientId == pttp.parient.Id)
    .ToList();

2) 选择测试参数

var testIds = patientTests.Select(x => x.TestId).ToList();
var testParameters = _db.TestParameters
    .Where(x => testIds.Contains(x.TestId))
    .ToList();

【讨论】：

谢谢马丁先生，我需要更多帮助，我想重新安排它与父子关系测试是父项，TestParameter 是测试的子项，例如 Test1 TestPara1 TestPara2 TestPara3 Test2 TestPara1 TestPara2 TestPara3