study delete func

Author: antgonza

qiita_db/study.py

@@ -107,6 +107,7 @@
 from .util import (check_required_columns, check_table_cols, convert_to_id,
                    get_environmental_packages, get_table_cols, infer_status)
 from .sql_connection import SQLConnectionHandler
+from .util import exists_table
 
 
 class Study(QiitaObject):
@@ -347,6 +348,58 @@ def create(cls, owner, title, efo, info, investigation=None):
 
         return cls(study_id)
 
+    @classmethod
+    def delete(cls, id_):
+        r"""Deletes the study from the database
+
+        Parameters
+        ----------
+        id_ : integer
+            The object identifier
+
+        Raises
+        ------
+        QiitaDBError
+            If the sample_(_id) table exists == a sample template exists
+        """
+        cls._check_subclass()
+
+        study = cls(id_)
+
+        conn_handler = SQLConnectionHandler()
+        if exists_table('sample_%d' % id_, conn_handler):
+            raise QiitaDBError('Study "%s" can not be erased because it has a '
+                               'sample template' % cls(id_).title)
+
+        queue = "delete_study_%d" % id_
+        conn_handler.create_queue(queue)
+
+        conn_handler.add_to_queue(
+            queue,
+            "DELETE FROM qiita.study_sample_columns WHERE study_id = %s",
+            (id_, ))
+
+        conn_handler.add_to_queue(
+            queue,
+            "DELETE FROM qiita.study_experimental_factor WHERE study_id = %s",
+            (id_, ))
+
+        conn_handler.add_to_queue(
+            queue,
+            "DELETE FROM qiita.study_pmid WHERE study_id = %s", (id_, ))
+
+        conn_handler.add_to_queue(
+            queue,
+            "DELETE FROM qiita.study_environmental_package WHERE study_id = "
+            "%s", (id_, ))
+
+        conn_handler.add_to_queue(
+            queue,
+            "DELETE FROM qiita.study WHERE study_id = %s", (id_, ))
+
+        conn_handler.execute_queue(queue)
+
+
 # --- Attributes ---
     @property
     def title(self):

qiita_db/test/test_study.py

@@ -11,7 +11,8 @@
 from qiita_db.user import User
 from qiita_db.data import RawData
 from qiita_db.util import convert_to_id
-from qiita_db.exceptions import QiitaDBColumnError, QiitaDBStatusError
+from qiita_db.exceptions import (
+    QiitaDBColumnError, QiitaDBStatusError, QiitaDBError)
 
 # -----------------------------------------------------------------------------
 # Copyright (c) 2014--, The Qiita Development Team.
@@ -438,6 +439,15 @@ def test_create_unknown_db_col(self):
             Study.create(User('test@foo.bar'), "Fried Chicken Microbiome",
                          [1], self.info)
 
+    def test_delete(self):
+        title = "Fried chicken microbiome"
+        study = Study.create(User('test@foo.bar'), title, [1], self.info)
+        study.delete(study.id)
+        self.assertFalse(study.exists(title))
+
+        with self.assertRaises(QiitaDBError):
+            Study.delete(1)
+
     def test_retrieve_title(self):
         self.assertEqual(self.study.title, 'Identification of the Microbiomes'
                          ' for Cannabis Soils')