如何使用Nodejs和PG查询PostgresSql json数据库

Question

我有一个postgreSQL数据库，它以json格式存储对表的所有更改，new_val和old_val
看起来像这样

new_val

  {"id":6,"id_item_type":7,"id_contact_as_producer":2,"id_contact_as_owner": 2,"comment":"3213","id_item_status":1,"imageurl":null,"id_station":2,"audit_id":null}";"  

old_val

{"id":6,"id_item_type":7,"id_contact_as_producer":2,"id_contact_as_owner":2,"comment":"3213","id_item_status":1,"imageurl":null,"id_station":null,"audit_id":null}"

我可以使用sql命令

在pgadmin中轻松查询

SELECT * FROM audit.history WHERE new_val ->> 'id_item_type' = '7'  

但是当我尝试从带有PG的nodejs查询它时，它就会挂起。我认为这是因为PG将其输入为字符串

var query = client.query('SELECT * FROM audit.history WHERE new_val ->> 'id_item_type' = '7'', 
        function (err, result) {
            done();
    });

所以我的问题基本上是，如何在Node中使用查询来自PG的数据库给我相同的结果？