Merge pull request #5 from Trevypants/main

Add Literal type handling

sqlmodel/main.py

@@ -52,9 +52,9 @@
 from .typing import SQLModelConfig
 
 if sys.version_info >= (3, 8):
-    from typing import get_args, get_origin
+    from typing import get_args, get_origin, Literal
 else:
-    from typing_extensions import get_args, get_origin
+    from typing_extensions import get_args, get_origin, Literal
 
 from typing_extensions import Annotated, _AnnotatedAlias
 
@@ -478,6 +478,15 @@ def get_sqlalchemy_type(field: FieldInfo) -> Any:
     elif org_type is pydantic.AnyUrl and type(type_) is _AnnotatedAlias:
         return AutoString(type_.__metadata__[0].max_length)
 
+    # Resolve Literal fields
+    if get_origin(type_) is Literal:
+        child_types = list({type(x) for x in get_args(type_)})
+        if len(child_types) != 1:
+            raise RuntimeError(
+                "Cannot have a Literal with multiple types as a SQLAlchemy field"
+            )
+        type_ = child_types[0]
+
     # The 3rd is PydanticGeneralMetadata
     metadata = _get_field_metadata(field)
     if type_ is None: