Merge pull request #625 from essence-tech/oracle-support

Feature: Oracle query runner

docs/datasources.rst

@@ -201,3 +201,18 @@ Vertica
 -  **Additional requirements**:
 
    - ``vertica-python`` python package
+
+Oracle
+------
+
+- **Options**
+
+   -  DSN Service name
+   -  User
+   -  Password
+   -  Host
+   -  Port
+
+- **Additional requirements**
+
+  - ``cx_Oracle`` python package. This requires the installation of the Oracle `instant client <http://www.oracle.com/technetwork/database/features/instant-client/index-097480.html>`__.

redash/query_runner/oracle.py

@@ -0,0 +1,175 @@
+import json
+import logging
+import sys
+
+from redash.query_runner import *
+from redash.utils import JSONEncoder
+
+try:
+    import cx_Oracle
+
+    TYPES_MAP = {
+        cx_Oracle.DATETIME: TYPE_DATETIME,
+        cx_Oracle.CLOB: TYPE_STRING,
+        cx_Oracle.LOB: TYPE_STRING,
+        cx_Oracle.FIXED_CHAR: TYPE_STRING,
+        cx_Oracle.FIXED_NCHAR: TYPE_STRING,
+        cx_Oracle.FIXED_UNICODE: TYPE_STRING,
+        cx_Oracle.INTERVAL: TYPE_DATETIME,
+        cx_Oracle.LONG_NCHAR: TYPE_STRING,
+        cx_Oracle.LONG_STRING: TYPE_STRING,
+        cx_Oracle.LONG_UNICODE: TYPE_STRING,
+        cx_Oracle.NATIVE_FLOAT: TYPE_FLOAT,
+        cx_Oracle.NCHAR: TYPE_STRING,
+        cx_Oracle.NUMBER: TYPE_FLOAT,
+        cx_Oracle.ROWID: TYPE_INTEGER,
+        cx_Oracle.STRING: TYPE_STRING,
+        cx_Oracle.TIMESTAMP: TYPE_DATETIME,
+        cx_Oracle.UNICODE: TYPE_STRING,
+    }
+
+
+    ENABLED = True
+except ImportError:
+    ENABLED = False
+
+logger = logging.getLogger(__name__)
+
+class Oracle(BaseQueryRunner):
+
+    @classmethod
+    def get_col_type(cls, col_type, scale):
+        if col_type == cx_Oracle.NUMBER:
+            return TYPE_FLOAT if scale > 0 else TYPE_INTEGER
+        else:
+            return TYPES_MAP.get(col_type, None)
+
+    @classmethod
+    def enabled(cls):
+        return ENABLED
+
+    @classmethod
+    def configuration_schema(cls):
+        return {
+            "type": "object",
+            "properties": {
+                "user": {
+                    "type": "string"
+                },
+                "password": {
+                    "type": "string"
+                },
+                "host": {
+                    "type": "string"
+                },
+                "port": {
+                    "type": "number"
+                },
+                "servicename": {
+                    "type": "string",
+                    "title": "DSN Service Name"
+                }
+            },
+            "required": ["servicename"],
+            "secret": ["password"]
+        }
+
+    @classmethod
+    def type(cls):
+        return "oracle"
+
+    def __init__(self, configuration_json):
+        super(Oracle, self).__init__(configuration_json)
+
+        dsn = cx_Oracle.makedsn(
+            self.configuration["host"],
+            self.configuration["port"],
+            service_name=self.configuration["servicename"])
+
+        self.connection_string = "{}/{}@{}".format(self.configuration["user"], self.configuration["password"], dsn)
+
+    def get_schema(self):
+        query = """
+        SELECT
+            user_tables.TABLESPACE_NAME,
+            all_tab_cols.TABLE_NAME,
+            all_tab_cols.COLUMN_NAME
+        FROM all_tab_cols
+        JOIN user_tables ON (all_tab_cols.TABLE_NAME = user_tables.TABLE_NAME)
+        """
+
+        results, error = self.run_query(query)
+
+        if error is not None:
+            raise Exception("Failed getting schema.")
+
+        results = json.loads(results)
+
+        schema = {}
+        for row in results['rows']:
+            if row['TABLESPACE_NAME'] != None:
+                table_name = '{}.{}'.format(row['TABLESPACE_NAME'], row['TABLE_NAME'])
+            else:
+                table_name = row['TABLE_NAME']
+
+            if table_name not in schema:
+                schema[table_name] = {'name': table_name, 'columns': []}
+
+            schema[table_name]['columns'].append(row['COLUMN_NAME'])
+
+        return schema.values()
+
+    @classmethod
+    def _convert_number(cls, value):
+        try:
+            return int(value)
+        except:
+            return value
+
+    @classmethod
+    def output_handler(cls, cursor, name, default_type, length, precision, scale):
+        if default_type in (cx_Oracle.CLOB, cx_Oracle.LOB):
+            return cursor.var(cx_Oracle.LONG_STRING, 80000, cursor.arraysize)
+
+        if default_type in (cx_Oracle.STRING, cx_Oracle.FIXED_CHAR):
+            return cursor.var(unicode, length, cursor.arraysize)
+
+        if default_type == cx_Oracle.NUMBER:
+            if scale <= 0:
+                return cursor.var(cx_Oracle.STRING, 255, outconverter=Oracle._convert_number, arraysize=cursor.arraysize)
+
+    def run_query(self, query):
+        connection = cx_Oracle.connect(self.connection_string)
+        connection.outputtypehandler = Oracle.output_handler
+
+        cursor = connection.cursor()
+
+        try:
+            cursor.execute(query)
+
+            if cursor.description is not None:
+                columns = self.fetch_columns([(i[0], Oracle.get_col_type(i[1], i[5])) for i in cursor.description])
+                rows = [dict(zip((c['name'] for c in columns), row)) for row in cursor]
+
+                data = {'columns': columns, 'rows': rows}
+                error = None
+                json_data = json.dumps(data, cls=JSONEncoder)
+            else:
+                error = 'Query completed but it returned no data.'
+                json_data = None
+        except cx_Oracle.DatabaseError as err:
+            logging.exception(err.message)
+            error = "Query failed. {}.".format(err.message)
+            json_data = None
+        except KeyboardInterrupt:
+            connection.cancel()
+            error = "Query cancelled by user."
+            json_data = None
+        except Exception as err:
+            raise sys.exc_info()[1], None, sys.exc_info()[2]
+        finally:
+            connection.close()
+
+        return json_data, error
+
+register(Oracle)

redash/settings.py

@@ -127,7 +127,8 @@ default_query_runners = [
     'redash.query_runner.hive_ds',
     'redash.query_runner.impala_ds',
     'redash.query_runner.vertica',
-    'redash.query_runner.treasuredata'
+    'redash.query_runner.treasuredata',
+    'redash.query_runner.oracle',
 ]
 
 enabled_query_runners = array_from_string(os.environ.get("REDASH_ENABLED_QUERY_RUNNERS", ",".join(default_query_runners)))

requirements_oracle_ds.txt

@@ -0,0 +1,4 @@
+# Requires installation of, or similar versions of:
+#    oracle-instantclient12.1-basic_12.1.0.2.0-2_amd64.deb
+#    oracle-instantclient12.1-devel_12.1.0.2.0-2_amd64.deb
+cx_Oracle==5.2