Dissolve Polygons

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Dissolves (aggregates) polygons based on user specified attributes. The resulting polygon data set does not contain multi-part polygons

Inputs

A polygon feature layer
Fields to be used for dissolving.
Update rules for the rest of the fields to be transferred.

Outputs

An aggregated polygon feature class.Only the polygons with common boundaries that have the same values for the dissolve fields will be aggregated
No multi-part polygons will be created.
The attributes will be transferred according the user specified rules. For the fields with no specified update rule, date and blob fields, the aggregated feature will carry the attributes of the first feature.

Notes:

The Dissolve Polygon Wizard works similarly to the dissolve function of GeoProcessing Wizard with a couple of improvements:
- Multiple dissolve fields can be used
- It does real dissolving – the non adjacent polygons with the same values for the dissolve fields will not be merged and no multi-part features will be created.
If multi-part features are already present in the layer to be dissolved, the Dissolve Polygons Wizard will explode them first. The attributes will be distributed as follows:
- For the fields that the user has selected SUM as an update rule, the values will be proportionally distributed between the parts
- For the rest of the fields the attributes will be copied over.
It is recommended the Explode Wizard to be used before dissolve in order to ensure proper distribution of the attribute values of the numeric fields.

Example:

Input Layer Dissolve field = “Dissolve”	After Dissolve:

ToolBox implementation
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Command line syntax

ET_GPDissolvePolygons<input_dataset> <out_feature class> <dissolve_field_list> {Update_Rules_List}

Parameters

Expression	Explanation
<input_dataset>	A Polyline feature class or feature layer
<out_feature class>	A String - the full name of the output feature class (A feature class with the same full name should not exist)
{dissolve_field_list}	A String - a list of field names to be used for dissolving.
{Update_Rules_List}	A String - a list of fields with their update rules.

Scripting syntax

ET_GPDissolvePolygons(input_dataset, out_feature class, dissolve_field_list,Update_Rules_List)

See the explanations above:
<> - required parameter
{} - optional parameter

Example Python script:

import arcpy
arcpy.ImportToolbox("C:/Program Files/ET SpatialTechniques/ET GeoWizards 11.0 for ArcGIS 10.1/ET GeoWizards.tbx")
arcpy.gp.toolbox = "C:/Program Files/ET SpatialTechniques/ET GeoWizards 11.0 for ArcGIS 10.1/ET GeoWizards.tbx"
input_dataset = "C:\\data\\suburbs.shp"
result = "C:\\data\\fgdb_test.gdb\\dissolved"
arcpy.gp.ET_GPDissolvePolygons(input_dataset, result, "Name;Type", "Population Sum; City First)