Question

在pic列中所有具有空字段的字段均应忽略。（甚至名称/地址也不应该显示）

$sql = "SELECT pic, title, address FROM 
 WP_2344432";  
$result = $conn->query($sql);  
if ($result->num_rows > 0) { // output data of 
   each row  
  while($row = $result->fetch_assoc()) {  
     echo '<br> <img src="'.$row['pic'].'"><br>Name: '. 
     $row['title']. '<br>Coordinates: ' . $row['address'] . 
      '<br>';  
   }  
 } else {
   echo "0 results"; 
}

Answer 1

如果--------------------------------------------------------------------------- ValueError Traceback (most recent call last) ~/bin/conda3/envs/work/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj) 339 pass 340 else: --> 341 return printer(obj) 342 # Finally look for special method names 343 method = get_real_method(obj, self.print_method) ~/bin/conda3/envs/work/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig) 242 243 if 'png' in formats: --> 244 png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs)) 245 if 'retina' in formats or 'png2x' in formats: 246 png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs)) ~/bin/conda3/envs/work/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs) 126 127 bytes_io = BytesIO() --> 128 fig.canvas.print_figure(bytes_io, **kw) 129 data = bytes_io.getvalue() 130 if fmt == 'svg': ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, **kwargs) 2210 orientation=orientation, 2211 dryrun=True, -> 2212 **kwargs) 2213 renderer = self.figure._cachedRenderer 2214 bbox_inches = self.figure.get_tightbbox(renderer) ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, *args, **kwargs) 515 516 def print_png(self, filename_or_obj, *args, **kwargs): --> 517 FigureCanvasAgg.draw(self) 518 renderer = self.get_renderer() 519 original_dpi = renderer.dpi ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self) 435 # if toolbar: 436 # toolbar.set_cursor(cursors.WAIT) --> 437 self.figure.draw(self.renderer) 438 # A GUI class may be need to update a window using this draw, so 439 # don't forget to call the superclass. ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs) 53 renderer.start_filter() 54 ---> 55 return draw(artist, renderer, *args, **kwargs) 56 finally: 57 if artist.get_agg_filter() is not None: ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer) 1491 1492 mimage._draw_list_compositing_images( -> 1493 renderer, self, artists, self.suppressComposite) 1494 1495 renderer.close_group('figure') ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite) 139 if not_composite or not has_images: 140 for a in artists: --> 141 a.draw(renderer) 142 else: 143 # Composite any adjacent images together ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs) 53 renderer.start_filter() 54 ---> 55 return draw(artist, renderer, *args, **kwargs) 56 finally: 57 if artist.get_agg_filter() is not None: ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe) 2633 renderer.stop_rasterizing() 2634 -> 2635 mimage._draw_list_compositing_images(renderer, self, artists) 2636 2637 renderer.close_group('axes') ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite) 139 if not_composite or not has_images: 140 for a in artists: --> 141 a.draw(renderer) 142 else: 143 # Composite any adjacent images together ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs) 53 renderer.start_filter() 54 ---> 55 return draw(artist, renderer, *args, **kwargs) 56 finally: 57 if artist.get_agg_filter() is not None: ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/axis.py in draw(self, renderer, *args, **kwargs) 1188 renderer.open_group(__name__) 1189 -> 1190 ticks_to_draw = self._update_ticks(renderer) 1191 ticklabelBoxes, ticklabelBoxes2 = self._get_tick_bboxes(ticks_to_draw, 1192 renderer) ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/axis.py in _update_ticks(self, renderer) 1026 1027 interval = self.get_view_interval() -> 1028 tick_tups = list(self.iter_ticks()) # iter_ticks calls the locator 1029 if self._smart_bounds and tick_tups: 1030 # handle inverted limits ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/axis.py in iter_ticks(self) 973 self.major.formatter.set_locs(majorLocs) 974 majorLabels = [self.major.formatter(val, i) --> 975 for i, val in enumerate(majorLocs)] 976 977 minorLocs = self.minor.locator() ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/axis.py in <listcomp>(.0) 973 self.major.formatter.set_locs(majorLocs) 974 majorLabels = [self.major.formatter(val, i) --> 975 for i, val in enumerate(majorLocs)] 976 977 minorLocs = self.minor.locator() ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/dates.py in __call__(self, x, pos) 632 'you have not informed the axis that it is ' 633 'plotting dates, e.g., with ax.xaxis_date()') --> 634 dt = num2date(x, self.tz) 635 return self.strftime(dt, self.fmt) 636 ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/dates.py in num2date(x, tz) 520 tz = _get_rc_timezone() 521 if not cbook.iterable(x): --> 522 return _from_ordinalf(x, tz) 523 else: 524 x = np.asarray(x) ~/bin/conda3/envs/work/lib/python3.6/site-packages/matplotlib/dates.py in _from_ordinalf(x, tz) 320 'non-datetime values are passed to an axis that ' 321 'expects datetime objects.'.format(ix)) --> 322 dt = datetime.datetime.fromordinal(ix).replace(tzinfo=UTC) 323 324 # Since the input date `x` float is unable to preserve microsecond ValueError: year 4233628 is out of range列中包含null，则将pic添加到您的选择中。如果它只是空的，则使用WHERE pic IS NULL。

WHERE pic = ''

或

$sql = "SELECT pic, title, address FROM WP_2344432 WHERE pic IS NOT NULL";

如何忽略图片列中所有为空的字段？

1 个答案: