Hi Umberto,<br><br>thanks for the explanation.<br><br>So this means with shapefiles in 5.0 null values would fall into the category of ([mycolumn] = 0) ? That seems almost even worse to me than an error ....<br><br>Mapserver really needs the concept of null values, but I can imagine this would require quite a bit of work ...
<br><br>Best regards,<br>Bart<br><br><div><span class="gmail_quote">On 10/8/07, <b class="gmail_sendername">Umberto Nicoletti</b> <<a href="mailto:umberto.nicoletti@gmail.com">umberto.nicoletti@gmail.com</a>> wrote:
</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Probably when the column is null it is evaluated by OGR to the empty<br>string and the expression (after replacing [HINDERCATEGORIE] with '')
<br>becomes ' = 1' which is invalid.<br><br>Just a side note: starting with mapserver 5 the shapefile provider<br>will return 0 for null numeric columns and '' for null strings.<br><br>Umberto<br><br>On 10/8/07, Bart van den Eijnden <
<a href="mailto:bartvde@gmail.com">bartvde@gmail.com</a>> wrote:<br>> Hi list,<br>><br>> I am posting this problem here since I don't know if it is an OGR problem or<br>> a Mapserver problem.<br>><br>
> Using Mapserver 5.0 and GDAL 1.4.1 we have an Oracle table that only<br>> contains null values for an integer column called HINDERCATEGORIE.<br>><br>> The expression used in Mapserver is:<br>><br>> EXPRESSION ([HINDERCATEGORIE] = 1)
<br>><br>> which will result in:<br>><br>> msEvalExpression: Expression parser error. Failed to parse expression: = 1<br>> msyyparse(): Expression parser error. parse error<br>><br>> [bart@hades rwsnl]$ shp2img -m
topografie.map -all_debug 10 -l<br>> vaarwegwerkzaamheid_live -o /tmp/bla.png<br>> msOGRFileOpen(vaarwegwerkzaamheid_live.ovf)...<br>> OGROPen(/data/OGC_UMN_services/rwsnl/./vaarwegwerkzaamheid_live.ovf)<br>> msyyparse(): Expression parser error. parse error
<br>> msEvalExpression: Expression parser error. Failed to parse expression: = 1<br>> msyyparse(): Expression parser error. parse error<br>> msEvalExpression: Expression parser error. Failed to parse expression: = 1
<br>> msyyparse(): Expression parser error. parse error<br>> msEvalExpression: Expression parser error. Failed to parse expression: = 1<br>> msyyparse(): Expression parser error. parse error<br>> msEvalExpression: Expression parser error. Failed to parse expression: = 1
<br>> msyyparse(): Expression parser error. parse error<br>> msEvalExpression: Expression parser error. Failed to parse expression: = 1<br>> msOGRLayerClose(vaarwegwerkzaamheid_live.ovf).<br>> msOGRFileClose(/data/OGC_UMN_services/rwsnl/./vaarwegwerkzaamheid_live.ovf,0).
<br>> msDrawMap(): Layer 3 (vaarwegwerkzaamheid_live), 0.761s<br>> msDrawLabelCacheGD(): labelcache_map_edge_buffer = -10<br>> msDrawMap(): Drawing Label Cache, 0.005s<br>> msDrawMap() total time: 0.781s<br>>
<br>> The layer definition is:<br>><br>> LAYER<br>> NAME "vaarwegwerkzaamheid_live"<br>> TYPE POINT<br>> CONNECTIONTYPE OGR<br>> CONNECTION "vaarwegwerkzaamheid_live.ovf"
<br>> DATA "vaarwegwerkzaamheid"<br>> PROCESSING "CLOSE_CONNECTION=DEFER"<br>> PROJECTION<br>> "init=epsg:28992"<br>> END<br>> METADATA<br>> "WMS_TITLE" "Vaarwegwerkzaamheden - staging omgeving"
<br>> END<br>> CLASS<br>> NAME "Unknown"<br>> EXPRESSION ([HINDERCATEGORIE] = 1)<br>> STYLE<br>> ANGLE 360<br>> COLOR 0 0 0<br>> OPACITY 100
<br>> SYMBOL "wegwerkzaamheid_3"<br>> END<br>> END<br>> END<br>><br>> Best regards,<br>> Bart<br>><br>><br></blockquote></div><br>