fix(spark): Support DB's TIMESTAMP_DIFF (#4373)

Author: VaggelisD

sqlglot/dialects/databricks.py

@@ -7,7 +7,6 @@
     date_delta_sql,
     build_date_delta,
     timestamptrunc_sql,
-    timestampdiff_sql,
 )
 from sqlglot.dialects.spark import Spark
 from sqlglot.tokens import TokenType
@@ -46,7 +45,6 @@ class Parser(Spark.Parser):
             "DATE_ADD": build_date_delta(exp.DateAdd),
             "DATEDIFF": build_date_delta(exp.DateDiff),
             "DATE_DIFF": build_date_delta(exp.DateDiff),
-            "TIMESTAMPDIFF": build_date_delta(exp.TimestampDiff),
             "GET_JSON_OBJECT": _build_json_extract,
         }
 
@@ -75,8 +73,6 @@ class Generator(Spark.Generator):
                 exp.Mul(this=e.expression, expression=exp.Literal.number(-1)),
                 e.this,
             ),
-            exp.DatetimeDiff: timestampdiff_sql,
-            exp.TimestampDiff: timestampdiff_sql,
             exp.DatetimeTrunc: timestamptrunc_sql(),
             exp.Select: transforms.preprocess(
                 [

sqlglot/dialects/spark.py

@@ -3,7 +3,7 @@
 import typing as t
 
 from sqlglot import exp
-from sqlglot.dialects.dialect import rename_func, unit_to_var
+from sqlglot.dialects.dialect import rename_func, unit_to_var, timestampdiff_sql, build_date_delta
 from sqlglot.dialects.hive import _build_with_ignore_nulls
 from sqlglot.dialects.spark2 import Spark2, temporary_storage_provider, _build_as_cast
 from sqlglot.helper import ensure_list, seq_get
@@ -108,6 +108,7 @@ class Parser(Spark2.Parser):
             "DATE_ADD": _build_dateadd,
             "DATEADD": _build_dateadd,
             "TIMESTAMPADD": _build_dateadd,
+            "TIMESTAMPDIFF": build_date_delta(exp.TimestampDiff),
             "DATEDIFF": _build_datediff,
             "DATE_DIFF": _build_datediff,
             "TIMESTAMP_LTZ": _build_as_cast("TIMESTAMP_LTZ"),
@@ -167,6 +168,8 @@ class Generator(Spark2.Generator):
             exp.StartsWith: rename_func("STARTSWITH"),
             exp.TsOrDsAdd: _dateadd_sql,
             exp.TimestampAdd: _dateadd_sql,
+            exp.DatetimeDiff: timestampdiff_sql,
+            exp.TimestampDiff: timestampdiff_sql,
             exp.TryCast: lambda self, e: (
                 self.trycast_sql(e) if e.args.get("safe") else self.cast_sql(e)
             ),

tests/dialects/test_spark.py

@@ -754,6 +754,17 @@ def test_spark(self):
             },
         )
 
+        self.validate_all(
+            "SELECT TIMESTAMPDIFF(MONTH, foo, bar)",
+            read={
+                "databricks": "SELECT TIMESTAMPDIFF(MONTH, foo, bar)",
+            },
+            write={
+                "spark": "SELECT TIMESTAMPDIFF(MONTH, foo, bar)",
+                "databricks": "SELECT TIMESTAMPDIFF(MONTH, foo, bar)",
+            },
+        )
+
     def test_bool_or(self):
         self.validate_all(
             "SELECT a, LOGICAL_OR(b) FROM table GROUP BY a",