bugfix: parse error for 'alter table xx comment 'xx''

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

@@ -2383,7 +2383,14 @@ public class MySqlStatementParser extends SQLStatementParser {
                         item.setCollate(this.exprParser.primary());
                     }
                     stmt.getItems().add(item);
-                } else {
+                } else if (lexer.token() == Token.COMMENT) {
+                    lexer.nextToken();
+                    if(lexer.token() == Token.EQ) {
+                        accept(Token.EQ);
+                    }
+                    stmt.getItems().add(new MySqlAlterTableOption("COMMENT", '\'' + lexer.stringVal() + '\''));
+                    lexer.nextToken();
+                }else {
                     break;
                 }
 

src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlAlterTableTest.java

@@ -16,6 +16,7 @@
 package com.alibaba.druid.bvt.sql.mysql;
 
 import org.junit.Assert;
+
 import junit.framework.TestCase;
 
 import com.alibaba.druid.sql.SQLUtils;
@@ -70,4 +71,13 @@ public class MySqlAlterTableTest extends TestCase {
         Assert.assertEquals("ALTER TABLE `test`.`tb1`\n\tCOLLATE = utf8_general_ci,\n\tPACK_KEYS = PACK ALL,\n\tENGINE = InnoDB", output);
     }
     
+    public void test_alter_5() throws Exception {
+        String sql = "ALTER TABLE t1 COMMENT '表的注释';";
+        MySqlStatementParser parser = new MySqlStatementParser(sql);
+        SQLStatement stmt = parser.parseStatementList().get(0);
+        parser.match(Token.EOF);
+        String output = SQLUtils.toMySqlString(stmt);
+        Assert.assertEquals("ALTER TABLE t1\n\tCOMMENT = '表的注释'", output);
+    }
+
 }