1 files changed, 5 insertions, 0 deletions
diff --git a/synapse/storage/engines/_base.py b/synapse/storage/engines/_base.py
index ad222e7e2d..9d82c59384 100644
--- a/synapse/storage/engines/_base.py
+++ b/synapse/storage/engines/_base.py
@@ -28,6 +28,11 @@ if TYPE_CHECKING:
     from synapse.storage.database import LoggingDatabaseConnection
 
 
+# A string that will be replaced with the appropriate auto increment directive
+# for the database engine, expands to an auto incrementing integer primary key.
+AUTO_INCREMENT_PRIMARY_KEYPLACEHOLDER = "$%AUTO_INCREMENT_PRIMARY_KEY%$"
+
+
 class IsolationLevel(IntEnum):
     READ_COMMITTED: int = 1
     REPEATABLE_READ: int = 2