Tests: Test composite synthetic uniqueness constraints

backlog.md

@@ -21,3 +21,5 @@ From dialect split-off.
  - https://docs.sqlalchemy.org/en/20/core/connections.html#sqlalchemy.engine.Connection.execution_options.params.stream_results
  - https://docs.sqlalchemy.org/en/20/core/connections.html#sqlalchemy.engine.Result.yield_per
 - https://github.com/jamescasbon/vertica-sqlalchemy
+- pandas: `index=True`
+- @cratedb: test_table_kwargs_unknown => ColumnUnknownException[Column bazqux unknown]

src/sqlalchemy_cratedb/support/polyfill.py

@@ -38,7 +38,10 @@ def check_uniqueness_factory(sa_entity, *attribute_names):
 
  This is used by CrateDB's MLflow adapter.
 
+ TODO: Maybe add to some helper function?
  TODO: Maybe enable through a dialect parameter `crate_polyfill_unique` or such.
+ TODO: Maybe derive from the model definition itself?
+ __table_args__ = (sa.UniqueConstraint("name", "user_id", name="unique_name_user"),)
  """
 
  # Synthesize a canonical "name" for the constraint,

tests/test_support_polyfill.py

@@ -74,7 +74,7 @@ class FooBar(Base):
  name = sa.Column(sa.String)
 
  # Add synthetic UNIQUE constraint on `name` column.
- listen(FooBar, "before_insert", check_uniqueness_factory(FooBar, "name"))
+ listen(FooBar, "before_insert", check_uniqueness_factory(FooBar, "id", "name"))
 
  Base.metadata.drop_all(engine, checkfirst=True)
  Base.metadata.create_all(engine, checkfirst=True)
@@ -86,11 +86,11 @@ class FooBar(Base):
  session.execute(sa.text("REFRESH TABLE foobar"))
 
  # Insert second record, violating the uniqueness constraint.
- bar_item = FooBar(id="bar", name="foo")
+ bar_item = FooBar(id="foo", name="foo")
  session.add(bar_item)
  with pytest.raises(IntegrityError) as ex:
  session.commit()
- assert ex.match("DuplicateKeyException in table 'foobar' on constraint 'name'")
+ assert ex.match("DuplicateKeyException in table 'foobar' on constraint 'id-name'")
 
 
 @pytest.mark.skipif(SA_VERSION < SA_1_4, reason="Feature not supported on SQLAlchemy 1.3 and earlier")