/// <summary>
/// 根据表达式删除指定类型的数据
/// </summary>
/// <typeparam name="T">指定类型</typeparam>
/// <param name="cri">表达式</param>
/// 前置条件
/// 参数cri不允许为空
public void Delete <T>(Criteria cri)
{
PreconditionAssert.IsNotNull(cri, ErrorMessages.NullReferenceException);
ORMHelper.CheckEntityIsNotReadOnly(typeof(T), ErrorMessages.EntityReadOnly);
DeleteCommandCreator dcc = new DeleteCommandCreator(_dbAccess);
dcc.EntityType = typeof(T);
dcc.criteria = cri;
dcc.deleteType = DeleteType.DeleteByCriteria;
DbCommand dbCommand = dcc.GetDbCommand();
_dbAccess.ExecCommand(dbCommand);
}
/// <summary>
/// 删除一个数据库中已有的对象，该对象的主键必须有值
/// 该对象为空或主键为空或删除失败会抛出异常
/// </summary>
/// <param name="entity">需要删除的实体</param>
/// 前置条件
/// 参数entity不允许为空
public void Delete(object entity)
{
//断言参入的参数为null或者空字符串（RErrorCode.NullReference - 0x00000001）
PreconditionAssert.IsNotNull(entity, ErrorMessages.NullReferenceException);
ORMHelper.EntityIsMappingDatabase(entity.GetType(), ErrorMessages.EntityMappingError);
ORMHelper.CheckEntityIsNotReadOnly(entity.GetType(), ErrorMessages.EntityReadOnly);
DeleteCommandCreator dcc = new DeleteCommandCreator(_dbAccess);
dcc.deleteType = DeleteType.Delete;
dcc.Entity = entity;
DbCommand dbCommand = dcc.GetDbCommand();
_dbAccess.ExecCommand(dbCommand);
}