Database layer for scenario and execute list

Pipfile

@@ -14,4 +14,4 @@ paramiko = "==2.7.1"
 pytest = "==5.4.3"
 scipy = "==1.4.1"
 tqdm = "==4.29.1"
-
+psycopg2 = "*"

powersimdata/data_access/README.md

@@ -0,0 +1,34 @@
+## About
+The `powersimdata.data_access` package contains implementations of storage to
+be used by the simulation framework generally. By providing a consistent api
+for any given set of data, we can decouple the storage medium from application
+logic.
+
+Currently, there are csv and sql implementations for the scenario list and
+execute list.
+
+## Usage
+To try this out, use the `stack.yml` provided in the tests directory to run a
+local instance of postgres, plus an admin ui. The integration tests for the db layer are run against this instance, and you can also connect to it with `psql`, the standard cli tool for interacting with postgres.
+
+Start the container using the following command, taken from the postgres
+[docs](https://github.com/docker-library/docs/blob/master/postgres/README.md).
+```
+docker-compose -f stack.yml up
+```
+
+Note - the schema are not automatically created (or part of source control) at this point, so to run the tests you'll need to do this manually. Improvements on this are forthcoming. 
+
+## Schema creation
+To get a working local database, run the container then do the following:
+
+```
+# connect to container, use password from stack.yml
+ psql -U postgres -h localhost
+```
+
+Once in the `psql` shell, you can create the database using `CREATE DATABASE
+psd;` then connect to it with `\c psd`. Make sure there is a file called
+`schema.sql` in your current directory then run `\i schema.sql`. Now if you run
+`\dt` you should see the tables have been created, and should be able to run
+the integration tests. 

powersimdata/data_access/__init__.py

@@ -1 +1 @@
-__all__ = ["csv_store", "execute_list", "scenario_list"]
+__all__ = ["csv_store", "sql_store", "execute_list", "scenario_list"]

powersimdata/data_access/execute_list.py

@@ -1,9 +1,67 @@
 from powersimdata.data_access.csv_store import CsvStore
+from powersimdata.data_access.sql_store import SqlStore, to_data_frame
 from powersimdata.utility import server_setup
 
 
+class ExecuteTable(SqlStore):
+    """Storage abstraction for execute list using sql database.
+    """
+
+    table = "execute_list"
+    columns = ["id", "status"]
+
+    def get_status(self, scenario_id):
+        """Get status of scenario by scenario_id
+        :param str scenario_id: the scenario id
+        :return: (*pandas.DataFrame*) -- results as a data frame.
+        """
+        query = self.select_where("id")
+        self.cur.execute(query, (scenario_id,))
+        result = self.cur.fetchmany()
+        return to_data_frame(result)
+
+    def get_execute_table(self, limit=None):
+        """Return the execute table as a data frame
+        :return: (*pandas.DataFrame*) -- execute list as a data frame.
+        """
+        query = self.select_all()
+        self.cur.execute(query)
+        if limit is None:
+            result = self.cur.fetchall()
+        else:
+            result = self.cur.fetchmany(limit)
+        return to_data_frame(result)
+
+    def add_entry(self, scenario_info):
+        """Add entry to execute list
+        :param collections.OrderedDict scenario_info: entry to add
+        """
+        scenario_id, status = scenario_info["id"], "created"
+        sql = self.insert()
+        self.cur.execute(sql, (scenario_id, status,))
+
+    def update_execute_list(self, status, scenario_info):
+        """Updates status of scenario in execute list
+
+        :param str status: execution status.
+        :param collections.OrderedDict scenario_info: entry to update
+        """
+        self.cur.execute(
+            "UPDATE execute_list SET status = %s WHERE id = %s",
+            (status, scenario_info["id"]),
+        )
+
+    def delete_entry(self, scenario_info):
+        """Deletes entry from execute list.
+
+        :param collections.OrderedDict scenario_info: entry to delete
+        """
+        sql = self.delete("id")
+        self.cur.execute(sql, (scenario_info["id"],))
+
+
 class ExecuteListManager(CsvStore):
-    """This class is responsible for any modifications to the execute list file.
+    """Storage abstraction for execute list using a csv file on the server.
 
     :param paramiko.client.SSHClient ssh_client: session with an SSH server.
     """