fix: reject DELETE statements missing a target table

DELETE, DELETE FROM, DELETE FROM WHERE ... and DELETE FROM USING ...
all parsed successfully into a Delete with a null table, and toString()
then printed the literal text "null" (DELETE FROM null WHERE 1 = 1).
The grammar's bare-FROM alternative never required a table to follow.

The production now validates that a target table was supplied in one
of the three supported positions (before FROM, after FROM, or via the
table list) through a requireDeleteSyntax() helper, matching the
existing requireAccessSyntax()/requireReplicationSyntax() pattern.

Author: princejain756

src/main/jjtree/net/sf/jsqlparser/parser/JSqlParserCC.jjt

@@ -2013,6 +2013,10 @@ public class CCJSqlParser extends AbstractJSqlParser<CCJSqlParser> {
         if (!valid) { throw new ParseException(message); }
     }
 
+    private static void requireDeleteSyntax(boolean valid, String message) throws ParseException {
+        if (!valid) { throw new ParseException(message); }
+    }
+
     private static <E extends Enum<E>> E replicationEnum(Class<E> type, String value) throws ParseException {
         try { return Enum.valueOf(type, MultiPartName.unquote(value).toUpperCase(Locale.ROOT)); }
         catch (IllegalArgumentException exception) { throw new ParseException("Unknown " + type.getSimpleName() + ": " + value); }
@@ -7193,6 +7197,8 @@ Delete Delete():
         if (joins != null && joins.size() > 0) {
             delete.setJoins(joins);
         }
+        requireDeleteSyntax(table != null || !tables.isEmpty(),
+                "DELETE requires a target table");
         return delete.withWithItemsList(with)
               .withTables(tables)
               .withTable(table)

src/test/java/net/sf/jsqlparser/statement/delete/DeleteTest.java

@@ -74,6 +74,20 @@ public void testDeleteDoesNotAllowLimitOffset() {
                 () -> parserManager.parse(new StringReader(statement)));
     }
 
+    @Test
+    public void testDeleteRequiresTargetTable() {
+        // a missing target must not parse into a Delete whose toString()
+        // prints a literal "null" for the absent table
+        for (String statement : new String[] {
+                "DELETE",
+                "DELETE FROM",
+                "DELETE FROM WHERE a = 1",
+                "DELETE FROM USING t"}) {
+            assertThrows(JSQLParserException.class,
+                    () -> parserManager.parse(new StringReader(statement)));
+        }
+    }
+
     @Test
     public void testDeleteWithOrderBy() throws JSQLParserException {
         String stmt = "DELETE FROM tablename WHERE a = 1 AND b = 1 ORDER BY col";