TGIS 503 WebGIS
Somethings possible with PostGIS Moving data in and out of PostGIS
"most popular and most capable of all the open source relational databases with spatial capabilities, and its features are constantly increasing...not an easy horse to ride." (GeoServer Beginner's Guide 2013 by Brian Youngblood and Stefano Iacovello page 110)
<?xml version="1.0" encoding="UTF-8"?>
<sld:StyledLayerDescriptor xmlns="http://www.opengis.net/sld"
xmlns:sld="http://www.opengis.net/sld"
xmlns:ogc="http://www.opengis.net/ogc"
xmlns:gml="http://www.opengis.net/gml" version="1.0.0">
<sld:NamedLayer>
<sld:Name>county_classificiation</sld:Name>
<sld:UserStyle>
<sld:Name>county_classification</sld:Name>
<sld:Title>County area classification</sld:Title>
<sld:FeatureTypeStyle>
<sld:Name>name</sld:Name>
<sld:Rule>
<sld:Title>Large counties</sld:Title>
<ogc:Filter>
<ogc:PropertyIsGreaterThanOrEqualTo>
<ogc:PropertyName>square_mil</ogc:PropertyName>
<ogc:Literal>5000</ogc:Literal>
</ogc:PropertyIsGreaterThanOrEqualTo>
</ogc:Filter>
<sld:PolygonSymbolizer>
<sld:Fill>
<sld:CssParameter
name="fill">#FF0000</sld:CssParameter>
</sld:Fill>
<sld:Stroke/>
</sld:PolygonSymbolizer>
</sld:Rule>
<sld:Rule>
<sld:Title>Small counties</sld:Title>
<ogc:Filter>
<ogc:PropertyIsLessThan>
<ogc:PropertyName>square_mil</ogc:PropertyName>
<ogc:Literal>5000</ogc:Literal>
</ogc:PropertyIsLessThan>
</ogc:Filter>
<sld:PolygonSymbolizer>
<sld:Fill>
<sld:CssParameter
name="fill">#0000FF</sld:CssParameter>
</sld:Fill>
<sld:Stroke/>
</sld:PolygonSymbolizer>
</sld:Rule>
</sld:FeatureTypeStyle>
</sld:UserStyle>
</sld:NamedLayer>
</sld:StyledLayerDescriptor>
OGC schemes if you have validation errors