docs: rename ql-training-rst > ql-training

docs/language/ql-training/query-examples/java/data-flow-java-1.ql

@@ -0,0 +1,11 @@
+import java
+
+class StringConcat extends AddExpr {
+  StringConcat() { getType() instanceof TypeString }
+}
+
+from MethodAccess ma
+where
+  ma.getMethod().getName().matches("sparql%Query") and
+  ma.getArgument(0) instanceof StringConcat
+select ma, "SPARQL query vulnerable to injection."