[英]How to resolve an SQLLite “no such table” error?
概述:我正在使用SQLLite查詢Windows Phone 8.1解決方案中的現有數據庫。 我已經調整了這個解決方案 ,將數據庫數據讀回我的項目。 但是當我使用數據庫連接調用ToList()時,我得到一個沒有這樣的數據庫錯誤 。
到目前為止,我已經附加了數據庫文件,我的DBHelper類使用以下代碼來查詢數據:
using (var dbConn = new SQLiteConnection(dbPath))
{
//No such table error thrown here ->
List<ZoneInfo> zoneInfo = dbConn.Table<ZoneInfo>().ToList<ZoneInfo>();
ObservableCollection<ZoneInfo> zoneInfoCollection = new ObservableCollection<ZoneInfo>(zoneInfo);
return zoneInfoCollection;
}
這是完整的DBHelper類,它引用我的解決方案中的現有DB文件並將其復制到設備的本地文件夾。 DB文件本身就在這里 。
調試步驟:
我應該采取哪些步驟來進一步調試SQLLite“無表”錯誤?
異常詳細信息:異常的確切細節如下所示,它告訴我沒有這樣的ZoneInfo表:
SQLite.SQLiteException was unhandled by user code
HResult=-2146233088
Message=no such table: ZoneInfo
Source=Parking Tag Picker WRT
StackTrace:
at SQLite.SQLite3.Prepare2(IntPtr db, String query)
at SQLite.SQLiteCommand.Prepare()
at SQLite.SQLiteCommand.<ExecuteDeferredQuery>d__0`1.MoveNext()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at SQLite.SQLiteCommand.ExecuteQuery[T]()
at SQLite.TableQuery`1.GetEnumerator()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
at Parking_Tag_Picker_WRT.Helpers.DatabaseHelper.ReadZones(String dbPath)
at Parking_Tag_Picker_WRT.ViewModel.TagRequestViewModel.InitZoneInfoAsync()
at Parking_Tag_Picker_WRT.TagRequestPage.OnNavigatedTo(NavigationEventArgs e)
InnerException:
ZoneInfo類:(將DB數據映射到類)
public class ZoneInfo
{
//The ObjectId property is marked as the Primary Key
[SQLite.PrimaryKey]
[Column("results_list_objectId")]
public string ObjectId { get; set; }
[Column("results_list_zone")]
public string ZoneName { get; set; }
[Column("results_list_tariff_ph")]
public int? TariffPH { get; set; }
[Column("results_list_tariff_pd")]
public int? TariffPD { get; set; }
[Column("results_list_restrictions")]
public string Restrictions { get; set; }
[Column("results_list_days_of_operation")]
public string DaysOpen { get; set; }
[Column("results_list_hours_of_operation")]
public string HoursOpen { get; set; }
public ZoneInfo()
{
}
public ZoneInfo(string objectId, string zoneName, int tariffPH, int tariffPD,
string restrictions, string daysOpen, string hoursOpen )
{
ObjectId = objectId;
ZoneName = zoneName;
TariffPH = tariffPH;
TariffPD = tariffPD;
Restrictions = restrictions;
DaysOpen = daysOpen;
HoursOpen = hoursOpen;
}
}
數據庫架構:
解決方案中的DB位置:
根據你的github repo,你的dbpath
只代表右邊的相對路徑Databases/DublinCityCouncilTable.db
。 現在,為了創建連接,您需要提供復制的數據庫的絕對路徑
using (var dbConn = new SQLiteConnection(Path.Combine(ApplicationData.Current.LocalFolder.Path,@"Databases\DublinCityCouncilTable.db"), true))
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