topic definition query on all layers in Python Questions

definition query on all layers

marklee1869 — Sun, 17 Mar 2024 11:42:01 GMT

I need to write python code to apply definition query for all layers at once, i already tried some code which i insert it below but it makes a new layers

# Set the workspace (change to your desired geodatabase or folder)
arcpy.env.workspace = r"D:\abo-ammar\geoParcel.gdb"

# List of feature classes (change to your desired feature class names)
feature_classes = ["parcels_corner", "parcels_dimension", "LINE_AMLAK", "Parcels"]

# Define the common query expression (change to your desired query)
query_expression = "parcel_no = 2"

# Loop through each feature class and apply the definition query
for feature_class in feature_classes:
# Get the existing layer
layer = arcpy.management.MakeFeatureLayer(feature_class, f"{feature_class}_Layer", query_expression)
print(f"Definition query applied to {feature_class}.")

# Print a success message
print("Definition queries applied to all specified feature classes.")

i want to know how to apply the same code but over the current layers not with generation of a copy of each layer

Re: definition query on all layers

Amir-Sarrafzadeh-Arasi — Mon, 18 Mar 2024 11:10:40 GMT

Dear marklee,

I hope you are doing well,

you just need to delete the "_layer" from your second element in the arcpy.management.MakeFeatureLayer function.

# Set the workspace (change to your desired geodatabase or folder)
arcpy.env.workspace = r"D:\abo-ammar\geoParcel.gdb"

# List of feature classes (change to your desired feature class names)
feature_classes = ["parcels_corner", "parcels_dimension", "LINE_AMLAK", "Parcels"]

# Define the common query expression (change to your desired query)
query_expression = "parcel_no = 2"

# Loop through each feature class and apply the definition query
for feature_class in feature_classes:
# Get the existing layer
layer = arcpy.management.MakeFeatureLayer(feature_class, f"{feature_class}", query_expression)
print(f"Definition query applied to {feature_class}.")

# Print a success message
print("Definition queries applied to all specified feature classes.")

Good luck

Re: definition query on all layers

RhettZufelt — Tue, 19 Mar 2024 17:55:17 GMT

So, are you trying to create new layers using the query_expression (as in makefeaturelayer) or are you trying to update the Definition Query on layers already loaded into the map?

If the latter, see this help document. The last two examples deal specifically with Definition Queries and should give you an idea how to modify.