Add employee hierarchy example

src/datacustomcode/templates/examples/employee_hierarchy/employee_data.csv

@@ -0,0 +1,13 @@
+id,name,position,manager_id
+1,Alice,CEO,
+2,Bob,VP Engineering,1
+3,Charlie,VP Sales,1
+4,David,Engineering Lead,2
+5,Eve,Engineering Lead,2
+6,Frank,Sales Manager,3
+7,Grace,Software Eng.,4
+8,Hannah,Software Eng.,4
+9,Ian,Software Eng.,5
+10,Jack,Sales Rep,6
+11,Kelly,Sales Rep,6
+12,Leo,Intern,7

src/datacustomcode/templates/examples/employee_hierarchy/entrypoint.py

@@ -0,0 +1,78 @@
+from pyspark.sql.functions import (
+    col,
+    concat_ws,
+    lit,
+)
+
+from datacustomcode.client import Client
+from datacustomcode.io.writer.base import WriteMode
+
+
+def main():
+    client = Client()
+
+    employees = client.read_dlo("Employee__dll").persist()
+    employees = employees.select("id__c", "manager_id__c", "name__c", "position__c")
+    employees.show()
+    employees_with_manager = (
+        employees.alias("e")
+        .join(
+            employees.alias("m"),
+            col("e.manager_id__c").cast("string") == col("m.id__c").cast("string"),
+            "left",
+        )
+        .select(
+            col("e.id__c"),
+            col("e.name__c"),
+            col("e.position__c"),
+            col("e.manager_id__c"),
+            col("m.name__c").alias("manager_name__c"),
+        )
+        .persist()
+    )
+
+    hierarchy_df = (
+        employees_with_manager.filter(col("manager_id__c").isNull())
+        .withColumn("hierarchy_level__c", lit(1))
+        .withColumn("management_chain__c", col("name__c"))
+        .persist()
+    )
+
+    current_level = 1
+
+    while True:
+        ewm = employees_with_manager.alias("ewm")
+        hdf = hierarchy_df.filter(col("hierarchy_level__c") == current_level).alias(
+            "hdf"
+        )
+
+        next_level_df = ewm.join(
+            hdf,
+            col("ewm.manager_id__c").cast("string") == col("hdf.id__c").cast("string"),
+            "inner",
+        ).select(
+            col("ewm.id__c"),
+            col("ewm.name__c"),
+            col("ewm.position__c"),
+            col("ewm.manager_id__c"),
+            col("ewm.manager_name__c"),
+            (col("hdf.hierarchy_level__c") + 1).alias("hierarchy_level__c"),
+            concat_ws(" | ", col("hdf.management_chain__c"), col("ewm.name__c")).alias(
+                "management_chain__c"
+            ),
+        )
+
+        if next_level_df.isEmpty():
+            break
+
+        hierarchy_df = hierarchy_df.union(next_level_df).persist()
+        current_level += 1
+
+    hierarchy_df = hierarchy_df.orderBy("hierarchy_level__c", "manager_id__c", "id__c")
+
+    dlo_name = "Employee_Hierarchy__dll"
+    client.write_to_dlo(dlo_name, hierarchy_df, WriteMode.APPEND)
+
+
+if __name__ == "__main__":
+    main()