tests: WIP df func test

tests/cases/standalone/flow/df_func.sql

@@ -0,0 +1,27 @@
+CREATE TABLE numbers_input_df_func (
+ number INT,
+ ts TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+ PRIMARY KEY(number),
+ TIME INDEX(ts)
+);
+
+CREATE FLOW test_numbers_df_func 
+SINK TO out_num_cnt_df_func
+AS 
+SELECT sum(abs(number)) FROM numbers_input_df_func GROUP BY tumble(ts, '1 second', '2021-07-01 00:00:00');
+
+INSERT INTO test_numbers_df_func 
+VALUES
+ (-20, "2021-07-01 00:00:00.200"),
+ (22, "2021-07-01 00:00:00.600");
+
+-- SQLNESS SLEEP 2s
+SELECT col_0, window_start, window_end FROM out_num_cnt_df_func;
+
+INSERT INTO test_numbers_df_func 
+VALUES
+ (23,"2021-07-01 00:00:01.000"),
+ (-24,"2021-07-01 00:00:01.500");
+
+-- SQLNESS SLEEP 2s
+SELECT col_0, window_start, window_end FROM out_num_cnt_df_func;