Feat(spark): support AS JSON suffix in describe statement closes #6866

Author: georgesittas

sqlglot/expressions.py

@@ -1618,6 +1618,7 @@ class Describe(Expression):
         "expressions": False,
         "partition": False,
         "format": False,
+        "as_json": False,
     }
 
 

sqlglot/generator.py

@@ -1328,8 +1328,9 @@ def describe_sql(self, expression: exp.Describe) -> str:
         partition = f" {partition}" if partition else ""
         format = self.sql(expression, "format")
         format = f" {format}" if format else ""
+        as_json = " AS JSON" if expression.args.get("as_json") else ""
 
-        return f"DESCRIBE{style}{format} {self.sql(expression, 'this')}{partition}"
+        return f"DESCRIBE{style}{format} {self.sql(expression, 'this')}{partition}{as_json}"
 
     def heredoc_sql(self, expression: exp.Heredoc) -> str:
         tag = self.sql(expression, "tag")

sqlglot/parser.py

@@ -2991,6 +2991,7 @@ def _parse_describe(self) -> exp.Describe:
             expressions=expressions,
             partition=partition,
             format=format,
+            as_json=self._match_text_seq("AS", "JSON"),
         )
 
     def _parse_multitable_inserts(self, comments: t.Optional[t.List[str]]) -> exp.MultitableInserts:

tests/dialects/test_databricks.py

@@ -12,6 +12,7 @@ def test_databricks(self):
         self.assertEqual(null_type.sql(), "NULL")
         self.assertEqual(null_type.sql("databricks"), "VOID")
 
+        self.validate_identity("DESCRIBE EXTENDED staging.onetrade_startb AS JSON")
         self.validate_identity("SELECT BITMAP_BIT_POSITION(10)")
         self.validate_identity("SELECT BITMAP_BUCKET_NUMBER(32769)")
         self.validate_identity("SELECT BITMAP_CONSTRUCT_AGG(value)")