Fix: build null types

tobymao · Jun 16, 2023 · cacf8bf · cacf8bf
1 parent 8e1b6a7
commit cacf8bf
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Showing 2 changed files with 7 additions and 2 deletions.
diff --git a/sqlglot/expressions.py b/sqlglot/expressions.py
@@ -3373,15 +3373,18 @@ class Type(AutoName):
         Type.DATETIME64,
     }
 
+    META_TYPES = {"UNKNOWN", "NULL"}
+
     @classmethod
     def build(
         cls, dtype: str | DataType | DataType.Type, dialect: DialectType = None, **kwargs
     ) -> DataType:
         from sqlglot import parse_one
 
         if isinstance(dtype, str):
-            if dtype.upper() == "UNKNOWN":
-                data_type_exp: t.Optional[Expression] = DataType(this=DataType.Type.UNKNOWN)
+            upper = dtype.upper()
+            if upper in DataType.META_TYPES:
+                data_type_exp: t.Optional[Expression] = DataType(this=DataType.Type[upper])
             else:
                 data_type_exp = parse_one(dtype, read=dialect, into=DataType)
 

diff --git a/tests/test_expressions.py b/tests/test_expressions.py
@@ -804,6 +804,8 @@ def test_data_type_builder(self):
         self.assertEqual(exp.DataType.build("NULLABLE").sql(), "NULLABLE")
         self.assertEqual(exp.DataType.build("HLLSKETCH", dialect="redshift").sql(), "HLLSKETCH")
         self.assertEqual(exp.DataType.build("HSTORE", dialect="postgres").sql(), "HSTORE")
+        self.assertEqual(exp.DataType.build("NULL").sql(), "NULL")
+        self.assertEqual(exp.DataType.build("NULL", dialect="bigquery").sql(), "NULL")
         self.assertEqual(exp.DataType.build("UNKNOWN").sql(), "UNKNOWN")
         self.assertEqual(exp.DataType.build("UNKNOWN", dialect="bigquery").sql(), "UNKNOWN")
         self.assertEqual(exp.DataType.build("UNKNOWN", dialect="snowflake").sql(), "UNKNOWN")