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How To: Describe layer properties in an enterprise geodatabase using ArcPy

Summary

Large enterprise data management systems involve multiple deployment environments including development, testing, performance, training, and production. When debugging a spatial issue in a particular environment, it is useful to compare metadata from the same layer in one or more environments. The describe_long SDE command in ArcSDE operations simplifies the process, however, it cannot be used in ArcMap. Instead, mimic the use of the SDE command with the ArcPy module.

Procedure

The following steps describe how to mimic the describe_long SDE command.

  1. Import the necessary module.
from arcpy import env
import arcpy
import datetime
  1. Define the desired workspace.
workspc = r"C:\Users\Test\AppData\Roaming\ESRI\Desktop10.7\ArcCatalog\TEST_sde.sde"
env.workspace = workspc
  1. Start a new class for the layer description, and define the constructor and query to describe the layer.
class LayerDesc:
    def __init__(self, workspc, layerTable, fcName):
        self.workspc = workspc
        self.layerTable = layerTable
        self.fcName = fcName

    def getConnectionProps(self):
        workspcDesc = arcpy.Describe(self.workspc)
        cp = workspcDesc.connectionProperties
        print "Connection and Feature Class Description:"
        print "%-12s %s" % ("\tServer:", cp.server)
        print "%-12s %s" % ("\tInstance:", cp.instance)
        print "%-12s %s" % ("\tDatabase:", cp.database)

    def querySDELayer(self):
        fcDesc = arcpy.Describe(self.fcName)
        spatial_ref = fcDesc.spatialReference
        spatialIndexes = arcpy.ListIndexes(self.fcName)
        
        if spatial_ref.name == "Unknown":
            print("{0} has an unknown spatial reference".format(self.fcName))
    
        else:
            srName = spatial_ref.name
            spatRefString = spatial_ref.exportToString()
            srDomain = spatial_ref.domain.split(" ")
            srPCSCode = spatial_ref.PCSCode
            srGCSCode = spatial_ref.GCSCode
            zUnits = spatial_ref.ZFalseOriginAndUnits.split(" ")
            xyTolerance = spatial_ref.XYTolerance
            xyResolution = spatial_ref.XYResolution
            siExists = fcDesc.hasSpatialIndex
            
                    
        try:
            conn = arcpy.ArcSDESQLExecute(workspc)
            sql = "SELECT * FROM {0} WHERE table_name = '{1}'".format(self.layerTable, self.fcName)
            sde_return = conn.execute(sql)
        except:
            try:
                conn = arcpy.ArcSDESQLExecute(workspc)
                sql = "SELECT * FROM {0} WHERE table_name = '{1}'".format(self.layerTable, self.fcName)
                sde_return = conn.execute(sql)
            except:
                try:
                    conn = arcpy.ArcSDESQLExecute(workspc)
                    sqlOra = "SELECT * FROM {0} WHERE table_name = '{1}'".format(self.layerTable, self.fcName)
                    sde_return = conn.execute(sqlOra)
                except Exception as err:
                    print sql
                print err
                sde_return = False
             
        if len(str(sde_return)) > 0:
            if sde_return == True:
                print "\tNo Layer ID found"
            else:
                for val in sde_return:
                    print "\tLayer ID: {0}".format(val[0])
                    print "\tLayer Description: {0}".format(val[1])
                    print "\tOwner: {0}".format(val[4])
                    print "\tShape Type: {0}".format(fcDesc.shapeType)
                    if spatial_ref.isHighPrecision == True:
                        print "\tHigh Precision: True"
                    else:
                        print "\tHigh Precision: False"
                    if val[6] != 1213464721:
                        print "eflag value: {0}".format(str(val[6]))
                        print "\tI/O Mode: Normal"
                    else:
                        print "eflag value: {0}".format(str(val[6]))
                        print "\tI/O mode: LOAD ONLY"
                    print "Spatial Reference Properties:"
                    print "\tLayer Envelope:"
                    print "\t\tMin X: {0}\t Min Y: {1}".format(val[11], val[12])
                    print "\t\tMax X: {0}\t Max Y: {1}".format(val[13], val[14])
                    if siExists == True:
                        print "\tSpatial Index: Yes"
                        for index in spatialIndexes:
                            if index.name[0] == "S" or index.name[0] == 's':
                                print "\t\t--> " + index.name
                    else:
                        print "\tSpatial Index: No"
                    print "\t\tGrid 1: {0}".format(val[8])
                    print "\t\tGrid 2: {0}".format(val[9])
                    print "\t\tGrid 3: {0}".format(val[10])
                    
                    print "\tXY Tolerance: {0}".format(xyTolerance)
                    print "\tXY Resolution %d.5" % xyResolution
                    print "\tXY Domain:"
                    print "\t\t" + srDomain[0] + "  " + srDomain[2]
                    print "\t\t" + srDomain[1] + "  " + srDomain[3]
                    print "\tZ Offset: {0}".format(zUnits[0])
                    print "\tZ Units: {0}".format(zUnits[1])
                    print "\tCoordinate System : {0}".format(srName)
                    print "\tSpatial Reference: {0}".format(spatRefString)
        
                    if srPCSCode > 0:
                        print "\t Projected Coordinate System Code:: {0}".format(srPCSCode)
                    else:
                        print "\tUndefined Projected Coordinate System"
                    if srGCSCode > 0:
                        print "\tGeographic Coordinate System Code:: {0}".format(srGCSCode)
                    else:
                        print "\tUndefined Geographic Coordinate System"
                    print "\tCreation Date: " + datetime.datetime.fromtimestamp(int(val[19])).strftime('%Y-%m-%d')
        else:
            print "Error reading layer ID"
        
        return sde_return
  1. Run the processes.
test = LayerDesc(workspc, "sde.sde_layers", "roads")
test.getConnectionProps()
test.querySDELayer()

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