#1427 - QueryCache should be cleared, if one of a dependent bean is updated

Initial work, does not include propagation across cluster.

src/main/java/io/ebeaninternal/server/query/SqlTree.java

@@ -3,6 +3,7 @@ package io.ebeaninternal.server.query;
 import io.ebeaninternal.api.SpiQuery;
 
 import java.util.ArrayList;
+import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
 
@@ -163,4 +164,13 @@ class SqlTree {
   boolean isSingleProperty() {
     return rootNode.isSingleProperty();
   }
+
+  /**
+   * Return the tables that are joined in this query.
+   */
+  Set<String> dependentTables() {
+    Set<String> tables = new LinkedHashSet<>();
+    rootNode.dependentTables(tables);
+    return tables;
+  }
 }