add more precise types to hive table from csv (apache#5267)

(cherry picked from commit b0eee12)

requirements.txt

@@ -34,6 +34,7 @@ six==1.11.0
 sqlalchemy==1.2.2
 sqlalchemy-utils==0.32.21
 sqlparse==0.2.4
+tableschema==1.1.0
 thrift==0.11.0
 thrift-sasl==0.3.0
 unicodecsv==0.14.1

setup.py

@@ -86,6 +86,7 @@ def get_git_sha():
         'sqlalchemy',
         'sqlalchemy-utils',
         'sqlparse',
+        'tableschema',
         'thrift>=0.9.3',
         'thrift-sasl>=0.2.1',
         'unicodecsv',

superset/db_engine_specs.py

@@ -36,7 +36,7 @@
 from sqlalchemy.engine.url import make_url
 from sqlalchemy.sql import text
 import sqlparse
-import unicodecsv
+from tableschema import Table
 from werkzeug.utils import secure_filename
 
 from superset import app, cache_util, conf, db, utils
@@ -90,7 +90,7 @@ def extra_table_metadata(cls, database, table_name, schema_name):
     @staticmethod
     def csv_to_df(**kwargs):
         kwargs['filepath_or_buffer'] = \
-            app.config['UPLOAD_FOLDER'] + kwargs['filepath_or_buffer']
+            config['UPLOAD_FOLDER'] + kwargs['filepath_or_buffer']
         kwargs['encoding'] = 'utf-8'
         kwargs['iterator'] = True
         chunks = pandas.read_csv(**kwargs)
@@ -112,7 +112,7 @@ def create_table_from_csv(form, table):
         def _allowed_file(filename):
             # Only allow specific file extensions as specified in the config
             extension = os.path.splitext(filename)[1]
-            return extension and extension[1:] in app.config['ALLOWED_EXTENSIONS']
+            return extension and extension[1:] in config['ALLOWED_EXTENSIONS']
 
         filename = secure_filename(form.csv_file.data.filename)
         if not _allowed_file(filename):
@@ -905,9 +905,15 @@ def fetch_result_sets(cls, db, datasource_type, force=False):
     @staticmethod
     def create_table_from_csv(form, table):
         """Uploads a csv file and creates a superset datasource in Hive."""
-        def get_column_names(filepath):
-            with open(filepath, 'rb') as f:
-                return next(unicodecsv.reader(f, encoding='utf-8-sig'))
+        def convert_to_hive_type(col_type):
+            """maps tableschema's types to hive types"""
+            tableschema_to_hive_types = {
+                'boolean': 'BOOLEAN',
+                'integer': 'INT',
+                'number': 'DOUBLE',
+                'string': 'STRING',
+            }
+            return tableschema_to_hive_types.get(col_type, 'STRING')
 
         table_name = form.name.data
         schema_name = form.schema.data
@@ -928,22 +934,27 @@ def get_column_names(filepath):
             if schema_name:
                 table_name = '{}.{}'.format(schema_name, table_name)
 
-        filename = form.csv_file.data.filename
         bucket_path = config['CSV_TO_HIVE_UPLOAD_S3_BUCKET']
 
         if not bucket_path:
             logging.info('No upload bucket specified')
             raise Exception(
                 'No upload bucket specified. You can specify one in the config file.')
 
-        upload_prefix = app.config['CSV_TO_HIVE_UPLOAD_DIRECTORY']
-        dest_path = os.path.join(table_name, filename)
+        table_name = form.name.data
+        filename = form.csv_file.data.filename
+        upload_prefix = config['CSV_TO_HIVE_UPLOAD_DIRECTORY']
 
-        upload_path = app.config['UPLOAD_FOLDER'] + \
+        upload_path = config['UPLOAD_FOLDER'] + \
             secure_filename(form.csv_file.data.filename)
-        column_names = get_column_names(upload_path)
-        schema_definition = ', '.join(
-            [s + ' STRING ' for s in column_names])
+
+        hive_table_schema = Table(upload_path).infer()
+        column_name_and_type = []
+        for column_info in hive_table_schema['fields']:
+            column_name_and_type.append(
+                '{} {}'.format(
+                    column_info['name'], convert_to_hive_type(column_info['type'])))
+        schema_definition = ', '.join(column_name_and_type)
 
         s3 = boto3.client('s3')
         location = os.path.join('s3a://', bucket_path, upload_prefix, table_name)