Add one more example

Author: mnd999

modules/ROOT/pages/errors/gql-errors/22NCC.adoc

@@ -1,7 +1,7 @@
 = 22NCC
 
 == Status description
-error: data exception - node element type specified incorrectly. The node element type `{ <<graphTypeElement>> }` identified by the label `{ <<label>> }` is different to the one specified in the query `{ <<graphTypeElement>> }`.
+error: data exception - node element type specified incorrectly. The node element type `{ <<graphTypeElement>>1 }` identified by the label `{ <<label>> }` is different to the one specified in the query `{ <<graphTypeElement>>2 }`.
 
 == Explanation
 This error occurs when attempting to drop a node element type from the graph type, but the specified element type does not match the existing one for the given label. 

modules/ROOT/pages/errors/gql-errors/22NCD.adoc

@@ -1,7 +1,7 @@
 = 22NCD
 
 == Status description
-error: data exception - relationship element type specified incorrectly. The relationship element type `{ <<graphTypeElement>> }` identified by the relationship type `{ <<relType>> }` is different to the one specified in the query `{ <<graphTypeElement>> }`.
+error: data exception - relationship element type specified incorrectly. The relationship element type `{ <<graphTypeElement>>1 }` identified by the relationship type `{ <<relType>> }` is different to the one specified in the query `{ <<graphTypeElement>>2 }`.
 
 == Explanation
 This error occurs when attempting to drop a relationship element type from the graph type, but the specified element type does not match the existing one for the given relationship type. 

modules/ROOT/pages/errors/gql-errors/22NCF.adoc

@@ -10,7 +10,7 @@ This also applies to graph type constraints defined inline of the graph type ele
 
 == Example scenario
 
-=== ALTER 
+=== ALTER existing constraint
 
 Given the existing graph type:
 
@@ -51,6 +51,44 @@ ALTER CURRENT GRAPH TYPE ADD {
 }
 ----
 
+=== Remove a KEY constraint using ALTER
+
+Given the existing graph type:
+
+[source,cypher]
+----
+ALTER CURRENT GRAPH TYPE SET {
+    ( :Person => {name :: STRING })
+}
+----
+
+Execute the query:
+
+[source,cypher]
+----
+ALTER CURRENT GRAPH TYPE ALTER {
+    ( :Person => {name :: STRING IS KEY } )
+}
+----
+
+The query returns an error with GQLSTATUS 22NCF and the status description:
+
+
+[source]
+----
+error: data exception - graph type constraint not supported. Graph type constraint definitions are not supported in the `ALTER GRAPH TYPE ALTER` operation.
+----
+
+To fix this, change the query as follows:
+
+[source, cypher]
+----
+ALTER CURRENT GRAPH TYPE ADD {
+    CONSTRAINT nameForKeyConstraint FOR (p:Person) REQUIRE p.name :: STRING IS KEY
+}
+
+----
+
 === DROP
 
 In this example we attempt to drop an undesignated constraint with an ALTER CURRENT GRAPH TYPE DROP query.