Fix issue of missing comma between joins in subjoin

Author: tomershay

src/main/java/net/sf/jsqlparser/statement/select/Join.java

@@ -195,7 +195,7 @@ public String toString() {
         if (isSimple() && isOuter()) {
             return "OUTER " + rightItem;
         } else if (isSimple()) {
-            return "" + rightItem;
+            return ", " + rightItem;
         } else {
             String type = "";
 

src/main/java/net/sf/jsqlparser/statement/select/SubJoin.java

@@ -65,7 +65,7 @@ public String toString() {
         StringBuilder sb = new StringBuilder();
         sb.append("(").append(left);
         for (Join j : joinList) {
-            sb.append(" ").append(j);
+            sb.append(j.isSimple() ? "" : " ").append(j);
         }
 
         sb.append(")").append((alias != null) ? (" " + alias.toString()) : "").append((pivot != null) ? " " + pivot : "");

src/test/java/net/sf/jsqlparser/statement/select/SelectTest.java

@@ -2009,6 +2009,12 @@ public void testWithStatement() throws JSQLParserException {
         assertSqlCanBeParsedAndDeparsed(stmt);
     }
 
+    @Test
+    public void testSubjoinWithJoins() throws JSQLParserException {
+        String stmt = "SELECT COUNT(DISTINCT `webProduct`.`id`) FROM (`webProduct`, `base`, `protectedBase`)";
+        assertSqlCanBeParsedAndDeparsed(stmt);
+    }
+
     @Test
     public void testWithUnionProblem() throws JSQLParserException {
         String stmt = "WITH test AS ((SELECT mslink FROM tablea) UNION (SELECT mslink FROM tableb)) SELECT * FROM tablea WHERE mslink IN (SELECT mslink FROM test)";