diff --git a/README.md b/README.md
index 039fbf6..a139187 100644
--- a/README.md
+++ b/README.md
@@ -740,4 +740,6 @@ The following guidelines indicate when the use of an index should be reconsidere
 
     ALTER TABLE table_name MODIFY column_name datatype NOT NULL;
     
+### ADD UNIQUE CONSTRAINT
 
+