GQL禁止文字错误,谷歌数据存储

Question

我正在尝试使用GQL从数据存储区中获取一些数据.

当我SELECT * FROM Kind提出请求时,它可以正常工作,我会收到数据.

但是,当我尝试:

SELECT * FROM kind where num < 1234

我得到一个不允许的字面错误.

我甚至尝试用引号做到这一点:

SELECT * FROM kind where num < '1234'

但我得到了同样的错误.

有没有人遇到过这个？

这是代码:

Query<Entity> query = Query.gqlQueryBuilder(Query.ResultType.ENTITY,             
          "SELECT * FROM " + kind + " WHERE num < '100'"
          ).build();
  QueryResults<Entity> results = datastore.run(query);
  while (results.hasNext()) {
    Entity result = results.next();
   myList.add(result.getString("num"));

Answer 1

您需要绑定查询参数而不是直接将其添加到查询中。

Query<Entity> query = Query.gqlQueryBuilder(Query.ResultType.ENTITY,             
                          "SELECT * FROM " + kind + " WHERE num < @num")
                      .setBinding("num", 100)
                      .build();
QueryResults<Entity> results = datastore.run(query);
while (results.hasNext()) {
    Entity result = results.next();
    myList.add(result.getString("num"));
...