Merge pull request #7 from dorosch/resolve/5

Added support of chunk_time_interval parameter

Author: dorosch

README.md

@@ -63,17 +63,21 @@ class Metric(Base):
     )
 ```
 
+## Parameters
+
+* [chunk_time_interval](6)
+
 ## Functions
 
 Timescaledb functions implemented:
 
-### [first(value, time)][6]
+### [first(value, time)][7]
 
 ```Python
 func.first(Metric.value, Metric.timestamp)
 ```
 
-### [last(value, time)][7]
+### [last(value, time)][8]
 
 ```Python
 func.last(Metric.value, Metric.timestamp)
@@ -85,5 +89,6 @@ func.last(Metric.value, Metric.timestamp)
 [3]: https://codecov.io/gh/dorosch/sqlalchemy-timescaledb
 [4]: https://pepy.tech/project/sqlalchemy-timescaledb
 [5]: https://docs.timescale.com/api/latest/hypertable/create_hypertable/#optional-arguments
-[6]: https://docs.timescale.com/api/latest/hyperfunctions/first/
-[7]: https://docs.timescale.com/api/latest/hyperfunctions/last/
+[6]: https://docs.timescale.com/api/latest/hypertable/set_chunk_time_interval/
+[7]: https://docs.timescale.com/api/latest/hyperfunctions/first/
+[8]: https://docs.timescale.com/api/latest/hyperfunctions/last/

sqlalchemy_timescaledb/dialect.py

@@ -33,11 +33,21 @@ def post_create_table(self, table):
 
     @staticmethod
     def ddl_hypertable(table_name, hypertable):
+        time_column_name = hypertable['time_column_name']
+        chunk_time_interval = hypertable.get('chunk_time_interval', '7 days')
+
+        if isinstance(chunk_time_interval, str):
+            if chunk_time_interval.isdigit():
+                chunk_time_interval = int(chunk_time_interval)
+            else:
+                chunk_time_interval = f"INTERVAL '{chunk_time_interval}'"
+
         return DDL(
             f"""
             SELECT create_hypertable(
                 '{table_name}',
-                '{hypertable['time_column_name']}',
+                '{time_column_name}',
+                chunk_time_interval => {chunk_time_interval},
                 if_not_exists => TRUE
             );
             """

tests/test_ddl_compiler.py

@@ -0,0 +1,43 @@
+import pytest
+from sqlalchemy import DDL
+
+from sqlalchemy_timescaledb.dialect import TimescaledbDDLCompiler
+
+
+class TestTimescaledbDDLCompiler:
+    def test_default_params(self):
+        assert TimescaledbDDLCompiler.ddl_hypertable(
+            'test', {'time_column_name': 'timestamp'}
+        ).compile().string == DDL(
+            f"""
+            SELECT create_hypertable(
+                'test',
+                'timestamp',
+                chunk_time_interval => INTERVAL '7 days',
+                if_not_exists => TRUE
+            );
+            """
+        ).compile().string
+
+    @pytest.mark.parametrize('interval,expected', [
+        ('1 days', "INTERVAL '1 days'"),
+        ('7 hour', "INTERVAL '7 hour'"),
+        (86400, 86400),
+        ('86400', 86400)
+    ])
+    def test_chunk_time_interval(self, interval, expected):
+        assert TimescaledbDDLCompiler.ddl_hypertable(
+            'test', {
+                'time_column_name': 'timestamp',
+                'chunk_time_interval': interval
+            }
+        ).compile().string == DDL(
+            f"""
+            SELECT create_hypertable(
+                'test',
+                'timestamp',
+                chunk_time_interval => {expected},
+                if_not_exists => TRUE
+            );
+            """
+        ).compile().string