Issue 3106: Use StringExpression, test case renamed, moved plsql to resource folder.

pmd-plsql/etc/grammar/PldocAST.jjt

@@ -2686,7 +2686,7 @@ ASTFetchStatement FetchStatement()  :
 ASTEmbeddedSqlStatement EmbeddedSqlStatement()  :
 {}
 {
-   <EXECUTE> <IMMEDIATE> Expression()
+   <EXECUTE> <IMMEDIATE> StringExpression()
 	[ <INTO> Name() ("," Name())* ]
 	[ <USING> [ <IN> [ <OUT> ] | <OUT> ]  Expression() ("," [ <IN> [ <OUT> ] | <OUT> ] Expression())* ]
 	[ ( <RETURN> | <RETURNING> )  <INTO> Expression() ("," Expression())*] ";"

pmd-plsql/src/test/java/net/sourceforge/pmd/lang/plsql/ast/PLSQLParserTest.java

@@ -75,7 +75,7 @@ public class PLSQLParserTest extends AbstractPLSQLParserTst {
     }
 
     @Test
-    public void testCaseIssue3106() {
-        plsql.parse("CREATE OR REPLACE PROCEDURE bar\nIS\n  v_link varchar2(10) := 'xxx';\nBEGIN\n  EXECUTE IMMEDIATE 'drop database link ' || v_link;\nEND bar;");
+    public void testExecuteImmediateIssue3106() {
+        plsql.parseResource("ExecuteImmediateIssue3106.pls");
     }
 }

pmd-plsql/src/test/resources/net/sourceforge/pmd/lang/plsql/ast/ExecuteImmediateIssue3106.pls

@@ -0,0 +1,11 @@
+--
+-- BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+--
+
+CREATE OR REPLACE PROCEDURE bar
+IS
+    v_link varchar2(10) := 'xxx';
+BEGIN
+    -- EXECUTE IMMEDIATE with an expression instead of just a literal or variable.
+    EXECUTE IMMEDIATE 'drop database link ' || v_link;
+END bar;