clickhosue不支持关键字 exist，这个解决起来有点麻烦了

[qiujunlin]

{    
    "User": {
        "id}{@": {
            "from": "Comment",
            "Comment": {
                "momentId": 15
            }
        }
    }
}

生成sql：SELECT * FROM `test`.`apijson_user` WHERE  (  ( EXISTS (SELECT * FROM `test`.`Comment` WHERE  (  (`momentId` = 15)  ) ) )  )  LIMIT 1

手动修改为如下后执行正确

SELECT * FROM `test`.`apijson_user` WHERE  15 in (  (SELECT `momentId` FROM `test`.`Comment`  ) )   LIMIT 1

执行错误：

cc.blynk.clickhouse.except.ClickHouseException: ClickHouse exception, code: 62, host: null, port: 0; Code: 62, e.displayText() = DB::Exception: Syntax error: failed at position 71 ('`test`'): `test`.`Comment` WHERE  (  (`momentId` = 15)  ) ) )  )  LIMIT 1 FORMAT TabSeparatedWithNamesAndTypes
. Expected one of: DoubleColon, LIKE, GLOBAL NOT IN, AS, DIV, IS, UUID, OR, QuestionMark, BETWEEN, NOT LIKE, MOD, AND, Comma, alias, IN, ILIKE, Dot, NOT ILIKE, NOT, token, NOT IN, GLOBAL IN (version 21.7.5.29 (official build))