Fix: array<unknown>

sqlglot/expressions.py

@@ -3532,11 +3532,6 @@ class Type(AutoName):
         Type.DATETIME64,
     }
 
-    META_TYPES = {
-        "UNKNOWN",
-        "NULL",
-    }
-
     @classmethod
     def build(
         cls,
@@ -3561,16 +3556,15 @@ def build(
         from sqlglot import parse_one
 
         if isinstance(dtype, str):
-            upper = dtype.upper()
-            if upper in DataType.META_TYPES:
-                data_type_exp = DataType(this=DataType.Type[upper])
-            else:
-                try:
-                    data_type_exp = parse_one(dtype, read=dialect, into=DataType)
-                except ParseError:
-                    if udt:
-                        return DataType(this=DataType.Type.USERDEFINED, kind=dtype, **kwargs)
-                    raise
+            if dtype.upper() == "UNKNOWN":
+                return DataType(this=DataType.Type.UNKNOWN, **kwargs)
+
+            try:
+                data_type_exp = parse_one(dtype, read=dialect, into=DataType)
+            except ParseError:
+                if udt:
+                    return DataType(this=DataType.Type.USERDEFINED, kind=dtype, **kwargs)
+                raise
         elif isinstance(dtype, DataType.Type):
             data_type_exp = DataType(this=dtype)
         elif isinstance(dtype, DataType):

sqlglot/parser.py

@@ -197,6 +197,8 @@ class Parser(metaclass=_Parser):
         TokenType.INET,
         TokenType.IPADDRESS,
         TokenType.IPPREFIX,
+        TokenType.UNKNOWN,
+        TokenType.NULL,
         *ENUM_TYPE_TOKENS,
         *NESTED_TYPE_TOKENS,
     }

sqlglot/tokens.py

@@ -158,6 +158,7 @@ class TokenType(AutoName):
     FIXEDSTRING = auto()
     LOWCARDINALITY = auto()
     NESTED = auto()
+    UNKNOWN = auto()
 
     # keywords
     ALIAS = auto()
@@ -644,6 +645,7 @@ class Tokenizer(metaclass=_Tokenizer):
         "THEN": TokenType.THEN,
         "TRUE": TokenType.TRUE,
         "UNION": TokenType.UNION,
+        "UNKNOWN": TokenType.UNKNOWN,
         "UNNEST": TokenType.UNNEST,
         "UNPIVOT": TokenType.UNPIVOT,
         "UPDATE": TokenType.UPDATE,

tests/test_expressions.py

@@ -846,6 +846,9 @@ def test_data_type_builder(self):
         )
         self.assertEqual(exp.DataType.build("USER-DEFINED").sql(), "USER-DEFINED")
 
+        self.assertEqual(exp.DataType.build("ARRAY<UNKNOWN>").sql(), "ARRAY<UNKNOWN>")
+        self.assertEqual(exp.DataType.build("ARRAY<NULL>").sql(), "ARRAY<NULL>")
+
     def test_rename_table(self):
         self.assertEqual(
             exp.rename_table("t1", "t2").sql(),