support mysql invisible index

src/main/java/com/alibaba/druid/sql/ast/SQLIndexOptions.java

@@ -20,8 +20,13 @@ public class SQLIndexOptions extends SQLObjectImpl {
     private SQLExpr comment;
     private String algorithm;
     private String lock;
+    private boolean invisible;
     private List<SQLAssignItem> otherOptions = new ArrayList<SQLAssignItem>();
 
+    public SQLIndexOptions() {
+
+    }
+
     public String getIndexType() {
         return indexType;
     }
@@ -120,6 +125,14 @@ public class SQLIndexOptions extends SQLObjectImpl {
         }
     }
 
+    public boolean isInvisible() {
+        return invisible;
+    }
+
+    public void setInvisible(boolean invisible) {
+        this.invisible = invisible;
+    }
+
     public List<SQLAssignItem> getOtherOptions() {
         return otherOptions;
     }
@@ -154,5 +167,7 @@ public class SQLIndexOptions extends SQLObjectImpl {
             item1.setParent(parent);
             options.otherOptions.add(item1);
         }
+
+        options.invisible = invisible;
     }
 }

src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlCreateTableParser.java

@@ -348,6 +348,10 @@ public class MySqlCreateTableParser extends SQLCreateTableParser {
                         stmt.getTableElementList().add(column);
                     }
 
+                    if (lexer.token() == Token.HINT) {
+                        lexer.nextToken();
+                    }
+
                     if (lexer.token() != Token.COMMA) {
                         break;
                     } else {

src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java

@@ -701,6 +701,10 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
         }
         print(')');
 
+        if (x.getIndexDefinition().hasOptions()) {
+            x.getIndexDefinition().getOptions().accept(this);
+        }
+
         SQLExpr comment = x.getComment();
         if (comment != null) {
             print0(ucase ? " COMMENT " : " comment ");

src/main/java/com/alibaba/druid/sql/parser/SQLExprParser.java

@@ -4776,6 +4776,14 @@ public class SQLExprParser extends SQLParser {
             if (lexer.token() == Token.COMMENT) {
                 lexer.nextToken();
                 indexDefinition.getOptions().setComment(primary());
+            } else if ((DbType.mysql == dbType) &&
+                    lexer.identifierEquals("INVISIBLE")) {
+                lexer.nextToken();
+                indexDefinition.getOptions().setInvisible(true);
+            } else if ((DbType.mysql == dbType) &&
+                    lexer.token == Token.HINT && lexer.stringVal().trim().equals("!80000 INVISIBLE")) {
+                lexer.nextToken();
+                indexDefinition.getOptions().setInvisible(true);
             } else if (DbType.mysql == dbType) {
                 switch (lexer.token()) {
                     case WITH:

src/main/java/com/alibaba/druid/sql/visitor/SQLASTOutputVisitor.java

@@ -6033,6 +6033,10 @@ public class SQLASTOutputVisitor extends SQLASTVisitorAdapter implements Paramet
         }
         */
 
+        if (x.isInvisible()) {
+            print0(ucase ? " INVISIBLE" : " invisible");
+        }
+
         SQLExpr keyBlockSize = x.getKeyBlockSize();
         if (keyBlockSize != null) {
             print0(ucase ? " KEY_BLOCK_SIZE = " : " key_block_size = ");