fix for passing test

Author: minleejae

src/main/java/net/sf/jsqlparser/statement/create/table/Index.java

@@ -154,15 +154,15 @@ public String toString() {
         String idxSpecText = PlainSelect.getStringList(idxSpec, false, false);
         String keyword = (indexKeyword != null) ? " " + indexKeyword : "";
         String head =
-                (type != null ? type : "") + keyword + (!name.isEmpty() ? " " + getName() : "");
-        String tail = PlainSelect.getStringList(columns, true, true)
-                + (!"".equals(idxSpecText) ? " " + idxSpecText : "");
+                (type != null ? type : "") +
+                        keyword +
+                        (!name.isEmpty() ? " " + getName() : "") +
+                        (using != null ? " USING " + using : "");
 
-        if ("".equals(tail)) {
-            return head;
-        }
+        String tail = PlainSelect.getStringList(columns, true, true)
+                + (!idxSpecText.isEmpty() ? " " + idxSpecText : "");
 
-        return head + " " + tail;
+        return tail.isEmpty() ? head : head + " " + tail;
     }
 
     public Index withType(String type) {

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

@@ -6690,7 +6690,7 @@ CreateIndex CreateIndex():
     CreateIndex createIndex = new CreateIndex();
     Table table = null;
     List<Index.ColumnParams> colNames;
-    Token using;
+    String indexType;
     Index index = null;
     List<String> parameter = new ArrayList<String>();
     List<String> tailParameters = new ArrayList<String>();
@@ -6705,12 +6705,12 @@ CreateIndex CreateIndex():
     (
         LOOKAHEAD(3)(
             <K_ON> table=Table()
-            [ <K_USING> using=<S_IDENTIFIER> { index.setUsing(using.image); } ]
+            [ indexType=UsingIndexType() { index.setUsing(indexType); } ]
         )
         |
         (
-            [ <K_USING> using=<S_IDENTIFIER> {
-                    index.setUsing(using.image);
+            [ indexType=UsingIndexType() {
+                    index.setUsing(indexType);
                     createIndex.setIndexTypeBeforeOn(true);
                 }
             ]
@@ -7663,10 +7663,22 @@ void IndexOptionList(List<String> list) :
     )*
 }
 
+String UsingIndexType() :
+{
+    String sk = null;
+}
+{
+    <K_USING> ( sk = RelObjectName() )
+    {
+        return sk;
+    }
+}
+
 void IndexOption(List<String> list) :
 {
     Token tk1 = null;
     Token tk2 = null;
+    String sk1 = null;
     boolean useEqual = false;
 }
 {
@@ -7695,6 +7707,10 @@ void IndexOption(List<String> list) :
       {
         list.add("INVISIBLE");
       }
+    |
+      sk1 = UsingIndexType(){
+        list.add("USING " + sk1);
+      }
     )
 }
 
@@ -7819,19 +7835,26 @@ AlterExpression AlterExpression():
                 LOOKAHEAD(2) (
                   (tk=<K_KEY> { alterExp.setUk(true); } | tk=<K_INDEX>)
                   (
-                      LOOKAHEAD(2)
+                      LOOKAHEAD(3)
                       sk3 = RelObjectName()
+                      [ sk4 = UsingIndexType() ]
                       columnNames = ColumnsNamesList()
                       |
+                      [ sk4 = UsingIndexType() ]
                       columnNames = ColumnsNamesList()
                   )
+                  IndexOptionList(indexSpec = new ArrayList<String>())
                   {
-                    index = new Index().withType(tk.image).withName(sk3).withColumnsNames(columnNames);
+                    index = new Index()
+                            .withIndexKeyword(tk.image)
+                            .withName(sk3)
+                            .withUsing(sk4)
+                            .withColumnsNames(columnNames)
+                            .withIndexSpec(indexSpec);
+
                     alterExp.setIndex(index);
                   }
                   constraints=AlterExpressionConstraintState() { alterExp.setConstraints(constraints); }
-                  [ <K_USING> sk4=RelObjectName() { alterExp.addParameters("USING", sk4); }]
-                  [ LOOKAHEAD(2) index = IndexWithComment(index) { alterExp.setIndex(index); } ]
                 )
                 |
                 (

src/test/java/net/sf/jsqlparser/statement/alter/AlterTest.java

@@ -1964,18 +1964,42 @@ public void testAlterTableAddIndexWithOptions() throws JSQLParserException {
 
         Index index = indexExp.getIndex();
         assertNotNull(index);
-        assertEquals("INDEX", index.getIndexKeyword()); // 명시적 "INDEX" 키워드
+        assertEquals("INDEX", index.getIndexKeyword());
         assertEquals("idx_lastname", index.getName());
         assertEquals("last_name", index.getColumnsNames().get(0));
 
         List<String> indexSpec = index.getIndexSpec();
         assertNotNull(indexSpec);
-        assertEquals(3, indexSpec.size());
+        assertEquals(4, indexSpec.size());
         assertEquals("USING BTREE", indexSpec.get(0));
-        assertEquals("KEY_BLOCK_SIZE=16", indexSpec.get(1));
+        assertEquals("KEY_BLOCK_SIZE = 16", indexSpec.get(1));
         assertEquals("COMMENT 'Performance tuning'", indexSpec.get(2));
         assertEquals("VISIBLE", indexSpec.get(3));
 
         assertSqlCanBeParsedAndDeparsed(sql);
     }
+
+    @Test
+    public void testAlterTableAddIndex_UsingBeforeColumns() throws JSQLParserException {
+        String sql = "ALTER TABLE t ADD INDEX idx_name USING BTREE (col)";
+
+        Statement stmt = CCJSqlParserUtil.parse(sql);
+        Alter alter = (Alter) stmt;
+
+        assertEquals("t", alter.getTable().getFullyQualifiedName());
+
+        List<AlterExpression> alterExpressions = alter.getAlterExpressions();
+        assertEquals(1, alterExpressions.size());
+
+        AlterExpression expr = alterExpressions.get(0);
+        assertEquals(AlterOperation.ADD, expr.getOperation());
+
+        Index index = expr.getIndex();
+        assertEquals("idx_name", index.getName());
+        assertEquals("INDEX", index.getIndexKeyword());
+        assertEquals("BTREE", index.getUsing());
+        assertEquals(List.of("col"), index.getColumnsNames());
+
+        assertSqlCanBeParsedAndDeparsed(sql);
+    }
 }