diff --git a/.obsidian/workspace b/.obsidian/workspace
index f505214..3ef85b5 100644
--- a/.obsidian/workspace
+++ b/.obsidian/workspace
@@ -9,7 +9,7 @@
         "state": {
           "type": "markdown",
           "state": {
-            "file": "School/Development/Primary Key.md",
+            "file": "School/Development/Foreign Key.md",
             "mode": "source"
           }
         }
@@ -68,7 +68,7 @@
             "state": {
               "type": "backlink",
               "state": {
-                "file": "School/Development/Primary Key.md",
+                "file": "School/Development/Foreign Key.md",
                 "collapseAll": false,
                 "extraContext": false,
                 "sortOrder": "alphabetical",
@@ -87,8 +87,8 @@
   },
   "active": "bc6e8ad9aa0f44c3",
   "lastOpenFiles": [
-    "School/Development/Primary Key.md",
     "School/Development/Foreign Key.md",
+    "School/Development/Primary Key.md",
     "School/Development/SQL Database.md",
     "School/Analyse/OSI Model.md",
     "School/Analyse/Images/OSI-model.png",
diff --git a/School/Development/Foreign Key.md b/School/Development/Foreign Key.md
index 732f38b..12bb562 100644
--- a/School/Development/Foreign Key.md	
+++ b/School/Development/Foreign Key.md	
@@ -1,6 +1,8 @@
 # Foreign Key
 A Foreign key is a [[Constraint]] that protects links between tables. Foreign key is a attribute or attributes that link to the [[Primary Key]] of a other entity set (table).
 
-For 
-
+## Example
 
+|ID (PK)|Name|Age|Sex|Length|
+|-----|-----|-----|-----|-----|
+|1|Nick|21|M|190|
\ No newline at end of file
diff --git a/School/Development/Primary Key.md b/School/Development/Primary Key.md
index 1b696eb..384b28d 100644
--- a/School/Development/Primary Key.md	
+++ b/School/Development/Primary Key.md	
@@ -5,4 +5,8 @@ There can only be ONE primary per table and can consist of multiple attributes (
 
 A primary key is **not** required, but highly advised. Even if you don't use it its better to include one in your schema.
 
-## Exaple
+## Example
+
+**Name (PK) - Age - Sex - Length**
+
+In the table schema above, only one entity where the name is Nick can exist because Name is the primary key.