c# - Google Drive API Q 逻辑子句顺序

Question

所以我在尝试列出我的驱动器中的某些文件时遇到了问题，原始代码是:

var request = _DriveService.Files.List();
request.Q = $"name = '{Properties.Settings.Default.SomeFileName0}'" +
        $" or name = '{Properties.Settings.Default.SomeFileName1}'" +
        $" or name = '{Properties.Settings.Default.SomeFileName2}'" +
        $" or name = '{Properties.Settings.Default.SomeFileName3}'" +
        " and trashed = false" +
        $" and '{Properties.Settings.Default.MyParents[0]}' in parents";
request.Fields = "files(id, name, parents)";
var files = await request.ExecuteAsync();

问题是它返回了 12 个文件，而不是 4 个文件。经过一些测试和调整后，我意识到 google drive 忽略了 和 子句，因此它正在检索所有已删除的文件。

现在，有了这段代码，它就像一个魅力:

var parentsTrashed = $"and '{Properties.Settings.Default.Myparents[0]}' in parents and trashed = false";
var request = _DriveService.Files.List();
request.Q = $"name = '{Properties.Settings.Default.SomeFileName0}' {parentsTrashed}" +
    $" or name = '{Properties.Settings.Default.SomeFileName1}' {parentsTrashed}" +
    $" or name = '{Properties.Settings.Default.SomeFileName2}' {parentsTrashed}" +
    $" or name = '{Properties.Settings.Default.SomeFileName3}' {parentsTrashed}";
request.Fields = "files(id, name, parents)";
var files = await request.ExecuteAsync();

因此 and 和 or 子句需要按以下顺序排列:(name and and and) OR (name and and and and) OR 。 ...

我在文档或互联网上找不到任何关于此的指示:这是一个错误还是有意为之？不应该在文档中记录下来，或者它是我只是没有找到它，还是它是我直到现在才知道的标准东西(我是业余爱好者)？

Answer 1

虽然我不知道 Drive 查询中运算符优先级的具体规则，但如果您使用括号指定您的意思，它至少会更容易阅读:

var request = _DriveService.Files.List();
request.Q = $"(name = '{Properties.Settings.Default.SomeFileName0}'" +
        $" or name = '{Properties.Settings.Default.SomeFileName1}'" +
        $" or name = '{Properties.Settings.Default.SomeFileName2}'" +
        $" or name = '{Properties.Settings.Default.SomeFileName3}')" +
        " and trashed = false" +
        $" and '{Properties.Settings.Default.MyParents[0]}' in parents";
request.Fields = "files(id, name, parents)";
var files = await request.ExecuteAsync();

这样查询的形式是:

(name = name1 or name = name2 or name = name3 or name = name4)
and trashed = false and parentid in parents

(当然没有换行符。)

我怀疑在您当前的查询中，它实际上是:

name = name1 or name = name2 or name = name3 or
(name = name4 and trashed = false and parentid in parents)