Feat(redshift): improve transpilation of ADD_MONTHS function (#1945)

tobymao · Jul 21, 2023 · b82573b · b82573b
1 parent 46b5dfa
commit b82573b
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Showing 2 changed files with 12 additions and 1 deletion.
diff --git a/sqlglot/dialects/redshift.py b/sqlglot/dialects/redshift.py
@@ -27,6 +27,11 @@ class Redshift(Postgres):
     class Parser(Postgres.Parser):
         FUNCTIONS = {
             **Postgres.Parser.FUNCTIONS,
+            "ADD_MONTHS": lambda args: exp.DateAdd(
+                this=exp.TsOrDsToDate(this=seq_get(args, 0)),
+                expression=seq_get(args, 1),
+                unit=exp.var("month"),
+            ),
             "DATEADD": lambda args: exp.DateAdd(
                 this=exp.TsOrDsToDate(this=seq_get(args, 2)),
                 expression=seq_get(args, 1),
@@ -37,7 +42,6 @@ class Parser(Postgres.Parser):
                 expression=exp.TsOrDsToDate(this=seq_get(args, 1)),
                 unit=seq_get(args, 0),
             ),
-            "NVL": exp.Coalesce.from_arg_list,
             "STRTOL": exp.FromBase.from_arg_list,
         }
 

diff --git a/tests/dialects/test_redshift.py b/tests/dialects/test_redshift.py
@@ -10,6 +10,13 @@ def test_redshift(self):
         self.validate_identity("foo$")
         self.validate_identity("$foo")
 
+        self.validate_all(
+            "SELECT ADD_MONTHS('2008-03-31', 1)",
+            write={
+                "redshift": "SELECT DATEADD(month, 1, '2008-03-31')",
+                "trino": "SELECT DATE_ADD('month', 1, CAST(CAST('2008-03-31' AS TIMESTAMP) AS DATE))",
+            },
+        )
         self.validate_all(
             "SELECT STRTOL('abc', 16)",
             read={