Le portail francophone de la géomatique

    def processAlgorithm(self, parameters, context, feedback):
        
        DossierDestination="C:/Users/..."
        CheminParcelles = str(DossierDestination)+'/Parcelles_2021.shp'

        # suppression de la couche
        for layer in QgsProject.instance().mapLayers().values():
            if layer.name() == 'Parcelles suivies' :
                id=layer.id()
                source=layer.publicSource()
                QgsProject.instance().removeMapLayer(id)

        # requête
        conn_str = (
        r'DRIVER={SQL Server};'
        r'SERVER=###;'
        r'DATABASE=###;'
        r'UID=###;'
        r'PWD=###')
        conn = pyodbc.connect(conn_str)
        cursor = conn.cursor()
        

        parcelles = cursor.execute("""
        select
        ParcelleId
        FormeGeom.STAsText() 'Forme'
        from 
        """,[760,1, 12]).fetchall()
        
        def createLayer(text,output) :
            
            driver = ogr.GetDriverByName('Esri Shapefile')
            ds = driver.CreateDataSource(output)
            dest_srs = osr.SpatialReference()
            dest_srs.ImportFromEPSG(2154)
            layer = ds.CreateLayer('', dest_srs, ogr.wkbPolygon)

            layer.CreateField(ogr.FieldDefn('ParcelleId', ogr.OFTString))
                
            defn = layer.GetLayerDefn()

            id = 0
            for feat in text :
                feat = ogr.Feature(defn)
                feat.SetField('ParcelleId', text[id][0])

                geom = ogr.CreateGeometryFromWkt(str(text[id][1]))
                feat.SetGeometry(geom)
                layer.CreateFeature(feat)
                feat = geom = None 
                id += 1

            return output

        if parcelles != [] :    
            createLayer(parcelles,CheminParcelles)
            parcellesLayer = QgsVectorLayer(CheminParcelles,'Parcelles suivies','ogr')
            QgsProject.instance().addMapLayer(parcellesLayer,True)
            
        else :
            print('pas de retour requete parcelle')

        return {}