Feat!(snowflake): improve transpilation of TO_TIMESTAMP* variants (#4473

)

* Feat!(snowflake): improve transpilation of TO_TIMESTAMP* variants

* Use is_int method

sqlglot/dialects/snowflake.py

@@ -41,9 +41,12 @@ def _build_datetime(
 ) -> t.Callable[[t.List], exp.Func]:
     def _builder(args: t.List) -> exp.Func:
         value = seq_get(args, 0)
+        scale_or_fmt = seq_get(args, 1)
+
         int_value = value is not None and is_int(value.name)
+        int_scale_or_fmt = scale_or_fmt is not None and scale_or_fmt.is_int
 
-        if isinstance(value, exp.Literal):
+        if isinstance(value, exp.Literal) or (value and scale_or_fmt):
             # Converts calls like `TO_TIME('01:02:03')` into casts
             if len(args) == 1 and value.is_string and not int_value:
                 return (
@@ -55,11 +58,11 @@ def _builder(args: t.List) -> exp.Func:
             # Handles `TO_TIMESTAMP(str, fmt)` and `TO_TIMESTAMP(num, scale)` as special
             # cases so we can transpile them, since they're relatively common
             if kind == exp.DataType.Type.TIMESTAMP:
-                if int_value and not safe:
+                if not safe and (int_value or int_scale_or_fmt):
                     # TRY_TO_TIMESTAMP('integer') is not parsed into exp.UnixToTime as
                     # it's not easily transpilable
-                    return exp.UnixToTime(this=value, scale=seq_get(args, 1))
-                if not is_float(value.this):
+                    return exp.UnixToTime(this=value, scale=scale_or_fmt)
+                if not int_scale_or_fmt and not is_float(value.name):
                     expr = build_formatted_time(exp.StrToTime, "snowflake")(args)
                     expr.set("safe", safe)
                     return expr

tests/dialects/test_snowflake.py

@@ -124,6 +124,7 @@ def test_snowflake(self):
         self.validate_identity(
             "SELECT * FROM DATA AS DATA_L ASOF JOIN DATA AS DATA_R MATCH_CONDITION (DATA_L.VAL > DATA_R.VAL) ON DATA_L.ID = DATA_R.ID"
         )
+        self.validate_identity("TO_TIMESTAMP(col, fmt)")
         self.validate_identity(
             "CAST(x AS GEOGRAPHY)",
             "TO_GEOGRAPHY(x)",
@@ -670,6 +671,15 @@ def test_snowflake(self):
                 "snowflake": "SELECT a FROM test AS t QUALIFY ROW_NUMBER() OVER (PARTITION BY a ORDER BY Z) = 1",
             },
         )
+        self.validate_all(
+            "SELECT TO_TIMESTAMP(col, 'DD-MM-YYYY HH12:MI:SS') FROM t",
+            write={
+                "bigquery": "SELECT PARSE_TIMESTAMP('%d-%m-%Y %I:%M:%S', col) FROM t",
+                "duckdb": "SELECT STRPTIME(col, '%d-%m-%Y %I:%M:%S') FROM t",
+                "snowflake": "SELECT TO_TIMESTAMP(col, 'DD-mm-yyyy hh12:mi:ss') FROM t",
+                "spark": "SELECT TO_TIMESTAMP(col, 'dd-MM-yyyy hh:mm:ss') FROM t",
+            },
+        )
         self.validate_all(
             "SELECT TO_TIMESTAMP(1659981729)",
             write={