DbProviderFactoryRepository

gistfile1.cs

public class DbProviderFactoryRepository
{
    /// <summary>
    /// The table containing all the data.
    /// </summary>
    private DataTable dbProviderFactoryTable;
 
    /// <summary>
    /// Name of the configuration element.
    /// </summary>
    private const string DbProviderFactoriesElement = "DbProviderFactories";
 
    /// <summary>
    /// Initialize the repository.
    /// </summary>
    public DbProviderFactoryRepository()
    {
        OpenTable();
    }
 
    /// <summary>
    /// Opens the table.
    /// </summary>
    private void OpenTable()
    {
        // Open the configuration.
        var dataConfiguration = ConfigurationManager.GetSection("system.data") as System.Data.DataSet;
        if (dataConfiguration == null)
            throw new InvalidOperationException("Unable to open 'System.Data' from the configuration");
 
        // Open the provider table.
        if (dataConfiguration.Tables.Contains(DbProviderFactoriesElement))
            dbProviderFactoryTable = dataConfiguration.Tables[DbProviderFactoriesElement];
        else
            throw new InvalidOperationException("Unable to open the '" + DbProviderFactoriesElement + "' table");
    }
 
    /// <summary>
    /// Adds the specified provider.
    /// </summary>
    /// <param name="provider">The provider.</param>
    public void Add(DbProviderFactoryDescription provider)
    {
        Delete(provider);
        dbProviderFactoryTable.Rows.Add(provider.Name, provider.Description, provider.Invariant, provider.Type);
    }
 
    /// <summary>
    /// Deletes the specified provider if present.
    /// </summary>
    /// <param name="provider">The provider.</param>
    public void Delete(DbProviderFactoryDescription provider)
    {
        var row = dbProviderFactoryTable.Rows.Cast<DataRow>()
            .FirstOrDefault(o => o[2] != null && o[2].ToString() == provider.Invariant);
        if (row != null)
        {
            dbProviderFactoryTable.Rows.Remove(row);
        }
    }
 
    /// <summary>
    /// Gets all providers.
    /// </summary>
    /// <returns></returns>
    public IEnumerable<DbProviderFactoryDescription> GetAll()
    {
        return dbProviderFactoryTable.Rows.Cast<DataRow>()
            .Select(o => new DbProviderFactoryDescription(o));
    }
 
    /// <summary>
    /// Get provider by invariant.
    /// </summary>
    /// <param name="invariant"></param>
    /// <returns></returns>
    public DbProviderFactoryDescription GetByInvariant(string invariant)
    {
        var row = dbProviderFactoryTable.Rows.Cast<DataRow>()
            .FirstOrDefault(o => o[0] != null && o[0].ToString() == invariant);
        if (row != null)
        {
            return new DbProviderFactoryDescription(row);
        }
        else
        {
            return null;
        }
    }
}