Warn about ignoring unsupported constraints

Author: damian3031

tests/unit/sqlalchemy/test_compiler.py

@@ -19,6 +19,7 @@
 from sqlalchemy import select
 from sqlalchemy import String
 from sqlalchemy import Table
+from sqlalchemy.exc import SAWarning
 from sqlalchemy.schema import CreateTable
 from sqlalchemy.sql import column
 from sqlalchemy.sql import table
@@ -194,18 +195,21 @@ def test_try_cast(dialect):
 
 
 def test_catalogs_create_table_with_pk(dialect):
-    statement = CreateTable(table_with_pk)
-    query = statement.compile(dialect=dialect)
-    assert 'primary key' not in str(query).lower()
+    with pytest.warns(SAWarning, match="Trino does not support PRIMARY KEY constraints. Constraint will be ignored."):
+        statement = CreateTable(table_with_pk)
+        query = statement.compile(dialect=dialect)
+        assert 'primary key' not in str(query).lower()
 
 
 def test_catalogs_create_table_with_fk(dialect):
-    statement = CreateTable(table_with_fk)
-    query = statement.compile(dialect=dialect)
-    assert 'foreign key' not in str(query).lower()
+    with pytest.warns(SAWarning, match="Trino does not support FOREIGN KEY constraints. Constraint will be ignored."):
+        statement = CreateTable(table_with_fk)
+        query = statement.compile(dialect=dialect)
+        assert 'foreign key' not in str(query).lower()
 
 
 def test_catalogs_create_table_with_unique(dialect):
-    statement = CreateTable(table_with_unique)
-    query = statement.compile(dialect=dialect)
-    assert 'unique' not in str(query).lower()
+    with pytest.warns(SAWarning, match="Trino does not support UNIQUE constraints. Constraint will be ignored."):
+        statement = CreateTable(table_with_unique)
+        query = statement.compile(dialect=dialect)
+        assert 'unique' not in str(query).lower()

trino/sqlalchemy/compiler.py

@@ -14,6 +14,7 @@
 from sqlalchemy.sql import sqltypes
 from sqlalchemy.sql.base import DialectKWArgs
 from sqlalchemy.sql.functions import GenericFunction
+from sqlalchemy.util import warn as SAWarn
 
 # https://trino.io/docs/current/language/reserved.html
 RESERVED_WORDS = {
@@ -182,12 +183,15 @@ def visit_try_cast(self, element, **kw):
 
 class TrinoDDLCompiler(compiler.DDLCompiler):
     def visit_foreign_key_constraint(self, constraint, **kw):
+        SAWarn("Trino does not support FOREIGN KEY constraints. Constraint will be ignored.")
         return None
 
     def visit_primary_key_constraint(self, constraint, **kw):
+        SAWarn("Trino does not support PRIMARY KEY constraints. Constraint will be ignored.")
         return None
 
     def visit_unique_constraint(self, constraint, **kw):
+        SAWarn("Trino does not support UNIQUE constraints. Constraint will be ignored.")
         return None