我目前正在制作一个使用 Sqlite 来存储其中包含对象列表的对象的应用程序。在过去的一周里,我在尝试插入和检索对象时遇到了麻烦,想知道是否可以得到一些帮助。任何帮助将不胜感激!谢谢!
这是要使用 OneToMany 关系存储的对象的数据库:
[Table("Patient")]
public class PatientDB
{
[PrimaryKey]
public string ID { get; set;}
public string Name { get; set; }
[OneToMany(CascadeOperations = CascadeOperation.All)]
public List<Vitals> PatientVitals { get; set;}
}
[Table("PatientVitals")]
public class VitalsDB
{
[PrimaryKey]
public string PatientVitalID { get; set; }
public string Weight { get; set;}
[ForeignKey(typeof(PatientItem))]
public string ID { get; set; }
}
我有一个单独的对象,它以 json 的形式从 REST 服务传递给我,我已成功反序列化为以下对象:
pat = new Patient
{
ID = "123",
Name = "Doe",
List<Vitals> vitals = new List<Vitals>
{
new Vitals
{
PatientVitalID = "1",
Weight = "150",
ID = "123"
}
new Vitals
{
PatientVitalID = "2",
Weight = "160",
ID = "123"
}
}
};
以下是我将患者插入数据库的方法:
conn = DependencyService.Get<ISQLite>().GetConnection();
conn.CreateTable<PatientDB>();
conn.CreateTable<VitalsDB> ();
var patientToInsert = new PatientDB ();
patientToInsert.ID = pat.ID;
patientToInsert.Name = pat.Name;
conn.Insert(patientToInsert);
var vitalsToInsert = new List ();
foreach (var vital in pat.Vitals)
{
var vitalToInsert = new VitalsDB ();
vitalToInsert.PatientVitalID = vital.PatientVitalsID;
vitalToInsert.Weight = vital.Weight;
vitalsToInsert.Add(vitalToInsert);
}
conn.InsertAll (vitalsToInsert);
foreach (var vital in vitalsToInsert)
{
vital.SmartCardID = patientToInsert.SmartCardID;
conn.Update (vital);
}
这里我如何找回病人
public List<PatientDB> retrieveDBPatient(string ID)
{
return conn.Query<PatientDB> ("SELECT * FROM [Patient] WHERE [ID]= '" + ID + "'");
}
最后,报错信息
SQLite.Net.SQLiteException: Constraint
at SQLite.Net.PreparedSqlLiteInsertCommand.ExecuteNonQuery (System.Object[] source) [0x0016b] in <filename unknown>:0
at SQLite.Net.SQLiteConnection.Insert (System.Object obj, System.String extra, System.Type objType) [0x000bc] in <filename unknown>:0