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How to Use different kinds of datasources in UMN Mapserver layers

One of the very great things about the UMN Mapserver Web system is that it can support numerous kinds of datasources. In this brief excerpt we will provide examples of how to specify the more common data sources used for layers. The examples below are for Mapserver 4.6, but for the most part are applicable to lower versions.

File locations for file based datasources such as ESRI Shape and MapInfo tab files are defined relative to the SHAPEPATH attribute or as absolute paths. For example the beginning declaration of your .map file might look something like the below


MAP 
    #
    # Start of map file
    #

    NAME MYMAP
    
    EXTENT  732193.725550 2904132.702662 799614.090681 2971466.288170 
    
    SIZE 500 500
    SHAPEPATH "c:\mydata\"
    :
    :

ESRI Shapefile

The most common kind of data used in UMN Mapserver is the ESRI shapefile which has a .shp extension. For this kind of datasource you simply specify the location of the file without even specifying the extension. Below is a sample declaration of a polygon layer that uses a shape file

    LAYER
        NAME buildings
        TYPE POLYGON
        STATUS DEFAULT
        DATA buildings
        PROJECTION
            "init=epsg:2249"
        END
        CLASS
            OUTLINECOLOR 10 10 10
        END
    END

MapInfo Tab Files

Many datasources are available to mapserver via the GDAL OGR driver. Map Info is one of those datasources. Below example is what a mapinfo layer definition looks like. Note the tab file specified should be placed in the folder denoted by SHAPEPATH at top of map file



    LAYER
        NAME buildings
        STATUS DEFAULT
        MINSCALE 7000
        CONNECTIONTYPE OGR
        CONNECTION "buildings.tab" 
        TYPE POLYGON
        PROJECTION
            "init=epsg:2249"  
        END
        # -- MapInfo has projection information built in the tab file 
        # -- so you can often auto read this information with the below
        #PROJECTION
        # AUTO
        #END
        CLASS
            OUTLINECOLOR 10 10 10
        END
    END

PostGIS Layer

Mapserver has a custom driver for the PostGIS spatial database. In order to use this, your mapserver cgi or mapscript must be compiled with the PostGIS driver. Below is what a postgis mapserver layer looks like.



    LAYER
      CONNECTIONTYPE postgis
      NAME "buildings"
      CONNECTION "user=dbuser dbname=mydb host=myserver"
      # the_geom column is the name of a spatial geometry field in the table buildings
      DATA "the_geom from buildings"
      STATUS DEFAULT
      TYPE POLYGON
      # Note if you use a filter statement - this is basically like a where clause of the sql statement
      FILTER "storyhg > 2"
      CLASS
            OUTLINECOLOR 10 10 10
      END
    END

More complex PostGIS layer

LAYER
    NAME "projects"
    CONNECTIONTYPE postgis
    CONNECTION "user=myloginuser dbname=mydbname host=mydbhost password=mypass" 
    DATA "the_geom FROM (SELECT a.projid, a.projname, a.projtype, a.projyear, a.pid, parc.the_geom 
			FROM projects a INNER JOIN parcels parc ON a.parcel_id = parc.pid 
                         WHERE a.projyear = 2007) as foo USING UNIQUE projid USING SRID=2249" 
    STATUS OFF
    TYPE POLYGON
    CLASS
        NAME "Business Projects"
        EXPRESSION ('[projtype]' = 'Business')
        STYLE
            OUTLINECOLOR 204 153 51
            WIDTH 3
        END
    END
    CLASS
        NAME "Community Projects"
        EXPRESSION ('[projtype]' = 'Community')
        STYLE
            OUTLINECOLOR 204 0 0
            WIDTH 3
        END
    END

    PROJECTION
        "init=epsg:2249" 
    END
    METADATA
     "wms_title" "Projects"
     "wfs_title" "Projects"
      gml_include_items "all"
      wms_include_items "all"
    END
    DUMP TRUE
    TOLERANCE 10
END

WMS Layer

Mapserver has the ability to act as a WMS Server as well as a WMS Client. The WMS Client capabilities are accessed by defining WMS layers that connect to WMS servers. Below is an example of a WMS layer using the Microsoft Terraservices WMS Server.



    LAYER
          NAME "msterraservicedoq"
          TYPE RASTER
          STATUS DEFAULT
          CONNECTION "http://terraservice.net/ogcmap.ashx?"
          CONNECTIONTYPE WMS
          MINSCALE 3000
          MAXSCALE 20000
          #DEBUG ON
          METADATA
            "wms_srs"             "EPSG:26919"
            "wms_name"            "doq"
            "wms_server_version"  "1.1.1"
            "wms_format"          "image/jpeg"
            "wms_style"         "UTMGrid_Cyan"
            "wms_latlonboundingbox" "-71.19 42.23 -71 42.40"
          END
     END


Post Comments About How to Use different kinds of datasources in UMN Mapserver layers




 CommenterComment
6/4/2013 12:29:00 PMKiranI Need Some More Help on Pmapper

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