插入数据库时​​Xamarin.Android SQLiteException

Question

我在尝试插入我的sqlite db时不断收到此错误。其他插入工作正常，但它似乎没有超出这一点。有没有人遇到过这个错误？你怎么解决？

以下是显示错误的代码和应用程​​序输出。

    public long SaveSamplePoints(string endDate,string startDate,string Who,string altitude,string height)
    {
        double lat = 1.2607;
        double lon = 36.804;
        var dbconn =  new SQLiteConnection(dbHandler.WritableDatabase.Path) ;
    using(dbconn){
                 return dbconn.Insert (new SamplePointTable {
                 LATITUDE = lat,
                 LONGITUDE = lon,

               });
      }

输出如下：

[DataActivity] SQLite.SQLiteException: Constraint
[DataActivity]   at  SQLite.PreparedSqlLiteInsertCommand.ExecuteNonQuery (System.Object[] source)   [0x00000] in <filename unknown>:0 
[DataActivity]   at SQLite.SQLiteConnection.Insert (System.Object obj,  System.String extra, System.Type objType) [0x00000] in <filename unknown>:0 

修改 这就是SamplePointTable的样子：

[Table("Sample_Point")]
public class SamplePointTable
{
    // table sample points tags

    public static string TABLE_SAMPLE_POINT= "Sample_Point";

    [PrimaryKey, AutoIncrement,Column("_id")]
    public int SAMPLE_POINT_ID { get; set;}



    [Column("height")]
    public int HEIGHT{ get; set;}

    [Column("latitude")]
    public double LATITUDE { get; set;}

    [Column("longitude")]
    public double LONGITUDE { get; set;}


    [Column("start_date")]
    public DateTime START_DATE { get; set;}

    [Column("end_date")]
    public DateTime END_DATE{ get; set;}

    [Column("who")]
    public static string WHO { get; set;}


    [Column("user_id")]   //foreign key column
    public int USER_ID { get; set;}


        public static void OnCreate(SQLiteDatabase database){

    database.ExecSQL(CREATE_TABLE_SAMPLE_POINT);

    }

public static void OnUpgrade(SQLiteDatabase database, int oldVersion,
        int newVersion) {
        Log.Warn(typeof(SamplePointTable).Name, "Upgrading database from version "
            + oldVersion + " to " + newVersion
            + ", which will destroy all old data");
        database.ExecSQL("DROP TABLE IF EXISTS " + TABLE_SAMPLE_POINT);

        OnCreate(database);
    }