我想为添加到我的sql数据库的每个新行提供一个ID（唯一），而无需明确询问用户。我正在考虑使用bigint并增加与上一行ID相比增加的每一行的值。
示例：
name id
xyz 1
现在将另一个数据添加到该表中，例如name ='abc'，我希望ID自动增加为2，然后保存所有类似的图片
name id
xyz 1
abc 2
有什么办法可以做到？还是任何其他可以随每一行增加的数据类型？
P.S。我在python上使用sql，因此我可以访问最后一行，然后通过fetchall()查询向其添加1，但这似乎并不是有效的方法。
答案 0 :(得分：0)
您尝试使用sql中的身份。自动递增且唯一 https://www.w3schools.com/sql/sql_autoincrement.asp
查询：-
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-10-d68919405364> in <module>()
----> 1 df.iplot(kind='scatter',x='A',y='B',mode='markers',size=10)
C:\ProgramData\Anaconda3\lib\site-packages\cufflinks\plotlytools.py in _iplot(self, kind, data, layout, filename, sharing, title, xTitle, yTitle, zTitle, theme, colors, colorscale, fill, width, dash, mode, interpolation, symbol, size, barmode, sortbars, bargap, bargroupgap, bins, histnorm, histfunc, orientation, boxpoints, annotations, keys, bestfit, bestfit_colors, mean, mean_colors, categories, x, y, z, text, gridcolor, zerolinecolor, margin, labels, values, secondary_y, secondary_y_title, subplots, shape, error_x, error_y, error_type, locations, lon, lat, asFrame, asDates, asFigure, asImage, dimensions, asPlot, asUrl, online, **kwargs)
761 bargap=bargap,bargroupgap=bargroupgap,annotations=annotations,gridcolor=gridcolor,
762 dimensions=dimensions,
--> 763 zerolinecolor=zerolinecolor,margin=margin,is3d='3d' in kind,**l_kwargs)
764
765 if not data:
C:\ProgramData\Anaconda3\lib\site-packages\cufflinks\tools.py in getLayout(kind, theme, title, xTitle, yTitle, zTitle, barmode, bargap, bargroupgap, margin, dimensions, width, height, annotations, is3d, **kwargs)
199
200 theme_data = getTheme(theme)
--> 201 layout=go.Layout(theme_data['layout'])
202 layout['xaxis1'].update({'title':xTitle})
203 layout['yaxis1'].update({'title':yTitle})
C:\ProgramData\Anaconda3\lib\site-packages\plotly\graph_objs\_layout.py in __init__(self, arg, angularaxis, annotations, autosize, bargap, bargroupgap, barmode, barnorm, boxgap, boxgroupgap, boxmode, calendar, colorway, datarevision, direction, dragmode, font, geo, grid, height, hiddenlabels, hiddenlabelssrc, hidesources, hoverdistance, hoverlabel, hovermode, images, legend, mapbox, margin, orientation, paper_bgcolor, plot_bgcolor, polar, radialaxis, scene, selectdirection, separators, shapes, showlegend, sliders, spikedistance, template, ternary, title, titlefont, updatemenus, violingap, violingroupgap, violinmode, width, xaxis, yaxis, **kwargs)
3735 self.images = images if images is not None else _v
3736 _v = arg.pop('legend', None)
-> 3737 self.legend = legend if legend is not None else _v
3738 _v = arg.pop('mapbox', None)
3739 self.mapbox = mapbox if mapbox is not None else _v
C:\ProgramData\Anaconda3\lib\site-packages\plotly\basedatatypes.py in __setattr__(self, prop, value)
3601 if match is None:
3602 # Set as ordinary property
-> 3603 super(BaseLayoutHierarchyType, self).__setattr__(prop, value)
3604 else:
3605 # Set as subplotid property
C:\ProgramData\Anaconda3\lib\site-packages\plotly\basedatatypes.py in __setattr__(self, prop, value)
2702 prop in self._validators):
2703 # Let known properties and private properties through
-> 2704 super(BasePlotlyType, self).__setattr__(prop, value)
2705 else:
2706 # Raise error on unknown public properties
C:\ProgramData\Anaconda3\lib\site-packages\plotly\graph_objs\_layout.py in legend(self, val)
1224 @legend.setter
1225 def legend(self, val):
-> 1226 self['legend'] = val
1227
1228 # mapbox
C:\ProgramData\Anaconda3\lib\site-packages\plotly\basedatatypes.py in __setitem__(self, prop, value)
3587 if match is None:
3588 # Set as ordinary property
-> 3589 super(BaseLayoutHierarchyType, self).__setitem__(prop, value)
3590 else:
3591 # Set as subplotid property
C:\ProgramData\Anaconda3\lib\site-packages\plotly\basedatatypes.py in __setitem__(self, prop, value)
2665 # ### Handle compound property ###
2666 if isinstance(validator, CompoundValidator):
-> 2667 self._set_compound_prop(prop, value)
2668
2669 # ### Handle compound array property ###
C:\ProgramData\Anaconda3\lib\site-packages\plotly\basedatatypes.py in _set_compound_prop(self, prop, val)
2963 validator = self._validators.get(prop)
2964 # type: BasePlotlyType
-> 2965 val = validator.validate_coerce(val)
2966
2967 # Save deep copies of current and new states
C:\ProgramData\Anaconda3\lib\site-packages\_plotly_utils\basevalidators.py in validate_coerce(self, v)
1790
1791 elif isinstance(v, dict):
-> 1792 v = self.data_class(**v)
1793
1794 elif isinstance(v, self.data_class):
C:\ProgramData\Anaconda3\lib\site-packages\plotly\graph_objs\layout\_legend.py in __init__(self, arg, bgcolor, bordercolor, borderwidth, font, orientation, tracegroupgap, traceorder, x, xanchor, y, yanchor, **kwargs)
500 # ----------------------------------
501 _v = arg.pop('bgcolor', None)
--> 502 self.bgcolor = bgcolor if bgcolor is not None else _v
503 _v = arg.pop('bordercolor', None)
504 self.bordercolor = bordercolor if bordercolor is not None else _v
C:\ProgramData\Anaconda3\lib\site-packages\plotly\basedatatypes.py in __setattr__(self, prop, value)
2702 prop in self._validators):
2703 # Let known properties and private properties through
-> 2704 super(BasePlotlyType, self).__setattr__(prop, value)
2705 else:
2706 # Raise error on unknown public properties
C:\ProgramData\Anaconda3\lib\site-packages\plotly\graph_objs\layout\_legend.py in bgcolor(self, val)
62 @bgcolor.setter
63 def bgcolor(self, val):
---> 64 self['bgcolor'] = val
65
66 # bordercolor
C:\ProgramData\Anaconda3\lib\site-packages\plotly\basedatatypes.py in __setitem__(self, prop, value)
2674 # ### Handle simple property ###
2675 else:
-> 2676 self._set_prop(prop, value)
2677
2678 # Handle non-scalar case
C:\ProgramData\Anaconda3\lib\site-packages\plotly\basedatatypes.py in _set_prop(self, prop, val)
2904 # ------------
2905 validator = self._validators.get(prop)
-> 2906 val = validator.validate_coerce(val)
2907
2908 # val is None
C:\ProgramData\Anaconda3\lib\site-packages\_plotly_utils\basevalidators.py in validate_coerce(self, v, should_raise)
1068 validated_v = self.vc_scalar(v)
1069 if validated_v is None and should_raise:
-> 1070 self.raise_invalid_val(v)
1071
1072 v = validated_v
C:\ProgramData\Anaconda3\lib\site-packages\_plotly_utils\basevalidators.py in raise_invalid_val(self, v)
214 typ=type_str(v),
215 v=repr(v),
--> 216 valid_clr_desc=self.description()))
217
218 def raise_invalid_elements(self, invalid_els):
ValueError:
Invalid value of type 'builtins.str' received for the 'bgcolor' property of layout.legend
Received value: 'pearl02'
The 'bgcolor' property is a color and may be specified as:
- A hex string (e.g. '#ff0000')
- An rgb/rgba string (e.g. 'rgb(255,0,0)')
- An hsl/hsla string (e.g. 'hsl(0,100%,50%)')
- An hsv/hsva string (e.g. 'hsv(0,100%,100%)')
- A named CSS color:
aliceblue, antiquewhite, aqua, aquamarine, azure,
beige, bisque, black, blanchedalmond, blue,
blueviolet, brown, burlywood, cadetblue,
chartreuse, chocolate, coral, cornflowerblue,
cornsilk, crimson, cyan, darkblue, darkcyan,
darkgoldenrod, darkgray, darkgrey, darkgreen,
darkkhaki, darkmagenta, darkolivegreen, darkorange,
darkorchid, darkred, darksalmon, darkseagreen,
darkslateblue, darkslategray, darkslategrey,
darkturquoise, darkviolet, deeppink, deepskyblue,
dimgray, dimgrey, dodgerblue, firebrick,
floralwhite, forestgreen, fuchsia, gainsboro,
ghostwhite, gold, goldenrod, gray, grey, green,
greenyellow, honeydew, hotpink, indianred, indigo,
ivory, khaki, lavender, lavenderblush, lawngreen,
lemonchiffon, lightblue, lightcoral, lightcyan,
lightgoldenrodyellow, lightgray, lightgrey,
lightgreen, lightpink, lightsalmon, lightseagreen,
lightskyblue, lightslategray, lightslategrey,
lightsteelblue, lightyellow, lime, limegreen,
linen, magenta, maroon, mediumaquamarine,
mediumblue, mediumorchid, mediumpurple,
mediumseagreen, mediumslateblue, mediumspringgreen,
mediumturquoise, mediumvioletred, midnightblue,
mintcream, mistyrose, moccasin, navajowhite, navy,
oldlace, olive, olivedrab, orange, orangered,
orchid, palegoldenrod, palegreen, paleturquoise,
palevioletred, papayawhip, peachpuff, peru, pink,
plum, powderblue, purple, red, rosybrown,
royalblue, saddlebrown, salmon, sandybrown,
seagreen, seashell, sienna, silver, skyblue,
slateblue, slategray, slategrey, snow, springgreen,
steelblue, tan, teal, thistle, tomato, turquoise,
violet, wheat, white, whitesmoke, yellow,
yellowgreen
如果已经存在表
CREATE TABLE Persons (
ID int NOT NULL AUTO_INCREMENT,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Age int,
PRIMARY KEY (ID)
);
答案 1 :(得分：0)
在表格中保留列名ID，例如
ID int NOT NULL AUTO_INCREMENT;
然后使用此方法
previousid=SELECT LAST_INSERT_ID();
primarykey=PK('cu',previousid);
print primarykey; //this will print a key like CU-18-000005
function PK(keycode,last_id)
{
seq=str_pad(last_id, 6, "0", STR_PAD_LEFT);
return strtoupper(keycode).'-'.date('y').'-'.seq;
}