Sitefinity - Shell for SQL command ExecuteNonQuery

IQueryService.cs

public interface IQueryService
{
    void CreateTable(string script);
    void InsertRecord(string script);
    IList<T> SelectRecord<T>(string script);
}

QueryService.cs

public class QueryService : IQueryService, IDisposable
{
    private PageManager _pageManager;
    private SitefinityOAContext _context;

    public QueryService()
    {
        _pageManager = PageManager.GetManager(string.Empty, ServiceConstant.QueryService.GetTransactionName());
        _context = (_pageManager.Provider as IOpenAccessDataProvider).GetContext();
    }

    public void Dispose()
    {
        _pageManager.Dispose();
        _context.Dispose();
    }

    private void CheckContext()
    {
        if (_context == null)
        {
            _context = (_pageManager.Provider as IOpenAccessDataProvider).GetContext();
        }
    }

    public void CreateTable(string script)
    {
        try
        {
            CheckContext();
            Logs.WriteTrace("Execute Create Table Script");
            _context.ExecuteNonQuery(script);
            _context.SaveChanges();
        }
        catch (Exception ex)
        {
            Logs.WriteError(ex);
        }
    }

    public void InsertRecord(string script)
    {
        try
        {
            CheckContext();
            Logs.WriteTrace("Execute Insert Record Script");
            _context.ExecuteNonQuery(script);
            _context.SaveChanges();
        }
        catch (Exception ex)
        {
            Logs.WriteError(ex);
        }
    }

    public IList<T> SelectRecord<T>(string script)
    {
        try
        {
            CheckContext();
            Logs.WriteTrace("Execute Select Record Script");
            return _context.ExecuteQuery<T>(script);
        }
        catch (Exception ex)
        {
            Logs.WriteError(ex);
        }

        return null;
    }
}