Fix!: consistently parse INTERVAL value as a string (#4986)

Author: georgesittas

sqlglot/parser.py

@@ -218,7 +218,7 @@ class Parser(metaclass=_Parser):
         "GENERATE_DATE_ARRAY": lambda args: exp.GenerateDateArray(
             start=seq_get(args, 0),
             end=seq_get(args, 1),
-            step=seq_get(args, 2) or exp.Interval(this=exp.Literal.number(1), unit=exp.var("DAY")),
+            step=seq_get(args, 2) or exp.Interval(this=exp.Literal.string(1), unit=exp.var("DAY")),
         ),
         "GLOB": lambda args: exp.Glob(this=seq_get(args, 1), expression=seq_get(args, 0)),
         "HEX": build_hex,

tests/dialects/test_bigquery.py

@@ -1515,8 +1515,8 @@ def test_bigquery(self):
         self.validate_all(
             "SELECT GENERATE_DATE_ARRAY('2016-10-05', '2016-10-08')",
             write={
-                "duckdb": "SELECT CAST(GENERATE_SERIES(CAST('2016-10-05' AS DATE), CAST('2016-10-08' AS DATE), INTERVAL 1 DAY) AS DATE[])",
-                "bigquery": "SELECT GENERATE_DATE_ARRAY('2016-10-05', '2016-10-08', INTERVAL 1 DAY)",
+                "duckdb": "SELECT CAST(GENERATE_SERIES(CAST('2016-10-05' AS DATE), CAST('2016-10-08' AS DATE), INTERVAL '1' DAY) AS DATE[])",
+                "bigquery": "SELECT GENERATE_DATE_ARRAY('2016-10-05', '2016-10-08', INTERVAL '1' DAY)",
             },
         )
         self.validate_all(