Reputation: 31
I tried everything today, in particular System.data.SQLite, that generates SegmentationFault when i try to create new SQLiteConnection. I have a local db in shared/res, and i want to interrogate it to retrieve some data. Somebody can help me?
App.xaml.cs
protected override void OnStart()
{
// Handle when your app starts
String db_name = "CTM_BUS.db";
String old_db_path = "/opt/usr/apps/com.feduss.example.BusFinder.Tizen.Wearable/shared/res/";
if (File.Exists(old_db_path + db_name))
{
SQLiteDatabase db = new SQLiteDatabase(new_db_path);
SQLiteCommand selectBusLines = new SQLiteCommand
("SELECT * from Routes");
DataTable res = db.GetDataTable(selectBusLines);
}
else
{
Console.WriteLine("File does not exist!");
}
}
SQLiteDatabase
public class SQLiteDatabase
{ private readonly string _dbConnection;
public SQLiteDatabase(string dataSource)
{
_dbConnection = string.Format("Data Source={0}", dataSource);
}
public DataTable GetDataTable(SQLiteCommand command)
{
if (command == null) throw new ArgumentNullException("command");
using (SQLiteConnection connection = new SQLiteConnection(_dbConnection))
{
connection.Open();
command.Connection = connection;
using (SQLiteDataReader reader = command.ExecuteReader())
{
DataTable result = new DataTable();
result.Load(reader);
return result;
}
}
}
public SQLiteCommand GetCommand(string sql)
{
if (string.IsNullOrEmpty(sql))
throw new ArgumentNullException("sql");
return new SQLiteCommand
{
CommandText = sql,
CommandType = CommandType.Text
};
}
public int ExecuteNonQuery(SQLiteCommand command)
{
if (command == null) throw new ArgumentNullException("command");
using (SQLiteConnection connection = new SQLiteConnection(_dbConnection))
{
connection.Open();
command.Connection = connection;
return command.ExecuteNonQuery();
}
}
}
Upvotes: 2
Views: 521
Reputation: 422
Use following nuget packages:
then:
define table schema, for example:
public class TableSchema
{
[AutoIncrement, PrimaryKey]
public int Id { get; set; }
public int Column1 { get; set; } = 0;
public int Column2 { get; set; } = 0;
}
BaseRepository class - it connects to database and return handler:
public abstract class BaseRepository
{
private readonly string _databasePath;
protected BaseRepository(string databasePath)
{
_databasePath = databasePath;
}
protected SQLite.SQLiteConnection ConnectDatabase()
{
SQLitePCL.raw.SetProvider(new SQLitePCL.SQLite3Provider_sqlite3());
SQLitePCL.raw.FreezeProvider();
return new SQLite.SQLiteConnection(_databasePath);
}
}
repository class (contains wrappers for common used queries):
public class Repository : BaseRepository
{
public Repository(string databasePath) : base(databasePath)
{
}
public List<TableSchema> GetAll()
{
using (SQLite.SQLiteConnection connection = ConnectDatabase())
{
return connection.Table<TableSchema>().ToList();
}
}
public List<TableSchema> Query(string query)
{
using (SQLite.SQLiteConnection sqlConnection = ConnectDatabase())
{
try
{
SQLite.SQLiteCommand queryCommand = sqlConnection.CreateCommand(query);
List<TableSchema> results = queryCommand.ExecuteQuery<TableSchema>();
return results;
}
catch (System.Exception e)
{
global::Tizen.Log.Error("TEST_TAG", e.Message);
return new List<TableSchema>();
}
}
}
}
and
class Sample
{
Repository _mapRepository;
public Sample()
{
_mapRepository = new Repository(App.Current.DirectoryInfo.Data + "db.sqlite3");
List<Table> allRecords = _mapRepository.GetAll();
}
}
Upvotes: 2