add new column to ds (#360)

* add new column to ds schema and query

Author: asuncepeda

iterate_snowflake/datasources/stock_prices.datasource

@@ -6,7 +6,8 @@ SCHEMA >
     `low` Float32,
     `close` Float32,
     `volume` Float32,
-    `split_coefficient` Float32
+    `split_coefficient` Float32,
+    `added` String
 
 ENGINE "MergeTree"
 ENGINE_PARTITION_KEY "toDate(date)"
@@ -16,5 +17,5 @@ IMPORT_SERVICE 'snowflake'
 IMPORT_CONNECTION_NAME 'sf_conn'
 IMPORT_EXTERNAL_DATASOURCE 'tinybird.samples.stock_prices'
 IMPORT_STRATEGY 'replace'
-IMPORT_QUERY 'SELECT date, symbol, open, high, low, close, volume, split_coefficient from tinybird.samples.stock_prices'
+IMPORT_QUERY 'SELECT date, symbol, open, high, low, close, volume, split_coefficient, added from tinybird.samples.stock_prices'
 IMPORT_SCHEDULE '@on-demand'