Question

不引用SERIAL ID。

类似的东西：

delete from users LAST 3

将删除表中的最后3行。

Answer 1

这将有效：

> # Tuning hyper-parameters for precision
> 
> --------------------------------------------------------------------------- AttributeError                            Traceback (most recent call
> last) <ipython-input-26-2d3979d9cbc5> in <module>()
>      24 
>      25     clf = GridSearchCV(clf, tuned_parameters, cv=10,
> ---> 26                        scoring='%s_macro' % score)
>      27     clf.fit(X_train, Y_train)
>      28 
> 
> /usr/local/lib/python3.6/dist-packages/sklearn/model_selection/_search.py
> in __init__(self, estimator, param_grid, scoring, fit_params, n_jobs,
> iid, refit, cv, verbose, pre_dispatch, error_score,
> return_train_score)    1075            
> return_train_score=return_train_score)    1076         self.param_grid
> = param_grid
> -> 1077         _check_param_grid(param_grid)    1078     1079     def _get_param_iterator(self):
> 
> /usr/local/lib/python3.6/dist-packages/sklearn/model_selection/_search.py
> in _check_param_grid(param_grid)
>     346 
>     347     for p in param_grid:
> --> 348         for name, v in p.items():
>     349             if isinstance(v, np.ndarray) and v.ndim > 1:
>     350                 raise ValueError("Parameter array should be one-dimensional.")
> 
> AttributeError: 'set' object has no attribute 'items'

如何在PostgreSQL中删除表中的一定数量的最后一行？

1 个答案: