fix(databricks): support IFF as a synonym for IF [CLAUDE] (#7488)

Databricks supports IFF as a synonym for the IF function. This adds
IFF to the Databricks parser's FUNCTIONS mapping so it correctly
parses to exp.If and transpiles to other dialects.

Closes #7347

Author: baruchoxman

sqlglot/parsers/databricks.py

@@ -14,6 +14,7 @@ class DatabricksParser(SparkParser):
 
     FUNCTIONS = {
         **SparkParser.FUNCTIONS,
+        "IFF": exp.If.from_arg_list,
         "GETDATE": exp.CurrentTimestamp.from_arg_list,
         "DATEADD": build_date_delta(exp.DateAdd),
         "DATE_ADD": build_date_delta(exp.DateAdd),

tests/dialects/test_databricks.py

@@ -491,6 +491,17 @@ def test_overlay(self):
             "SELECT OVERLAY('Spark SQL' PLACING 'ANSI ' FROM 7 FOR 0)",
         )
 
+    def test_iff(self):
+        # IFF is a synonym for IF in Databricks; it normalizes to IF on output
+        self.validate_all(
+            "SELECT IF(x > 0, 'positive', 'non-positive')",
+            read={"databricks": "SELECT IFF(x > 0, 'positive', 'non-positive')"},
+            write={
+                "databricks": "SELECT IF(x > 0, 'positive', 'non-positive')",
+                "snowflake": "SELECT IFF(x > 0, 'positive', 'non-positive')",
+            },
+        )
+
     def test_declare(self):
         self.validate_identity("DECLARE VAR x INT", "DECLARE x INT")
         self.validate_identity("DECLARE x INT")