feat: add initial check function

Author: cbrinson-rise8

src/recordlinker/database/__init__.py

@@ -9,13 +9,14 @@
 import typing
 
 from sqlalchemy import create_engine
-from sqlalchemy import orm
+from sqlalchemy import orm, inspect, MetaData
+from sqlalchemy.exc import SQLAlchemyError
 
 from recordlinker import models
 from recordlinker.config import settings
 
-
-def create_sessionmaker(init_tables: bool = True) -> orm.sessionmaker:
+#TODO: figure out wher this variable `verify_tables` is gonna come from
+def create_sessionmaker(init_tables: bool = True, verify_tables: bool = True) -> orm.sessionmaker:
     """
     Create a new sessionmaker for the database connection.
     """
@@ -25,10 +26,50 @@ def create_sessionmaker(init_tables: bool = True) -> orm.sessionmaker:
     if settings.connection_pool_max_overflow is not None:
         kwargs["max_overflow"] = settings.connection_pool_max_overflow
     engine = create_engine(settings.db_uri, **kwargs)
+    
     if init_tables:
         models.Base.metadata.create_all(engine)
+    if verify_tables:
+        verify_tables_match_orm(engine)
+
     return orm.sessionmaker(bind=engine)
 
+def verify_tables_match_orm(engine):
+    """
+    Verify that database tables match ORM definitions.
+    """
+    inspector = inspect(engine)
+    orm_metadata = models.Base.metadata  # Use ORM schema
+
+    for table_name, orm_table in orm_metadata.tables.items():
+        # Check if the table exists in the database
+        if not inspector.has_table(table_name):
+            raise SQLAlchemyError(
+                f"Table '{table_name}' is missing in the database."
+            )
+
+        # Retrieve database columns
+        db_columns = inspector.get_columns(table_name)
+        db_column_details = {col['name']: col for col in db_columns}
+
+        # Compare ORM and database columns
+        for orm_column in orm_table.columns:
+            column_name = orm_column.name
+
+            if column_name not in db_column_details:
+                raise SQLAlchemyError(
+                    f"Column '{column_name}' is missing in the database for table '{table_name}'."
+                )
+
+            db_col_type = db_column_details[column_name]['type']
+            orm_col_type = orm_column.type
+
+            if type(db_col_type) != type(orm_col_type):
+                raise SQLAlchemyError(
+                    f"Type mismatch for column '{column_name}' in table '{table_name}': "
+                    f"DB type is {db_col_type}, ORM type is {orm_col_type}."
+                )
+
 
 def get_session() -> typing.Iterator[orm.Session]:
     """