jeroos · August 20, 2025 16:22 · Mar 21, 2024 · Mar 21, 2024
diff --git a/gistfile1.txt → gistfile1.python b/gistfile1.txt → gistfile1.python
diff --git a/gistfile1.txt b/gistfile1.txt
@@ -0,0 +1,73 @@
+import json
+import os
+import duckdb
+import boto3
+import datetime
+from typing import Any, Dict
+
+
+def construct_prepared_sql_and_params(sql_template, bind_params):
+    single_value_params = {k: v for k, v in bind_params.items() if not isinstance(v, list)}
+    list_params = {k: v for k, v in bind_params.items() if isinstance(v, list)}
+
+    for key in single_value_params.keys():
+        sql_template = sql_template.replace(f"{{{key}}}", "?")
+
+    for key, values in list_params.items():
+        placeholders = ', '.join(['?'] * len(values))
+        sql_template = sql_template.replace(f"{{{key}}}", placeholders)
+
+    flat_params = []
+    for key in bind_params:
+        if key in single_value_params:
+            flat_params.append(single_value_params[key])
+        elif key in list_params:
+            flat_params.extend(list_params[key])
+
+    return sql_template, flat_params
+
+
+def serialize_dates(row):
+    for key, value in row.items():
+        if isinstance(value, datetime.date):
+            row[key] = value.strftime('%d-%m-%Y')
+    return row
+
+
+def lambda_handler(event: Dict[str, Any], context):
+    print("Duckdb Lambda received event: " + json.dumps(event, indent=4))
+    file_name = event.get('file_name')
+    sql = event.get('sql')
+    bind_params = event.get('bind_params', {})
+    return_type = event.get('return_type', 'List')
+
+    s3 = boto3.client('s3')
+    bucket_name = os.getenv('BUCKET_NAME')
+
+    local_file_name = f"/tmp/{file_name}"
+    os.makedirs(os.path.dirname(local_file_name), exist_ok=True)
+
+    s3.download_file(bucket_name, file_name, local_file_name)
+
+    conn = duckdb.connect(database=':memory:', read_only=False)
+    prepared_sql = sql % local_file_name
+
+    try:
+        prepared_sql, flat_params = construct_prepared_sql_and_params(prepared_sql, bind_params)
+        print(prepared_sql)
+        print(f"flat_params -> {flat_params}")
+        cursor = conn.execute(prepared_sql, parameters=flat_params)
+        columns = [description[0] for description in cursor.description]
+        fetched_results = [dict(zip(columns, row)) for row in cursor.fetchall()]
+
+        fetched_results = [serialize_dates(row) for row in fetched_results]
+
+        if return_type == 'Single':
+            results = fetched_results[0] if fetched_results else {}
+        else:
+            results = fetched_results
+    finally:
+        conn.close()
+
+    print("Duckdb Lambda processing completed")
+    return results