Question

我有这种格式的文件：

{
 "env" : "local",
 ....,
 "daily" : [
    {
     "executionParam1" : "Apple",
     "executionParam2" : "sour",
     "executionParam3" : "today",
     ...
    },
    {
     "executionParam1" : "Oranges",
     "executionParam2" : "sour",
     "executionParam3" : "tomorrow",
     ....
    }...
 ]

我使用MongoDB java驱动程序查询它。查询采用以下形式：

this.mongoDailyReportCollection = this.mongoDb.getCollection("environments");
Bson projection = fields(excludeId(),
                                 include("env", "daily"),
                                 Projections.elemMatch("daily",
                                                       and(eq("executionParam1", coll.getexecutionParam1()),
                                                           eq("executionParam2", coll.getexecutionParam2()),
                                                           eq("executionParam3", coll.getexecutionParam3()))));
long count = this.mongoDailyReportCollection.count(projection);

即使executionParam1是Apple，executionParam2还是今天，executionParam3也是如此，我仍然计算为0。如果我想更新与此文档匹配的文档，那么程序

Answer 1

您正在将投影文档发送到接受查询文档的[DllImport("user32.dll")] static extern bool GetKeyboardState(byte[] lpKeyState); [DllImport("user32.dll")] static extern uint MapVirtualKey(uint uCode, uint uMapType); [DllImport("user32.dll")] static extern IntPtr GetKeyboardLayout(uint idThread); [DllImport("user32.dll")] static extern int ToUnicodeEx(uint wVirtKey, uint wScanCode, byte[] lpKeyState, [Out, MarshalAs(UnmanagedType.LPWStr)] StringBuilder pwszBuff, int cchBuff, uint wFlags, IntPtr dwhkl); public static string KeyCodeToUnicode(System.Windows.Forms.Keys key) { byte[] keyboardState = new byte[255]; bool keyboardStateStatus = GetKeyboardState(keyboardState); if (!keyboardStateStatus) { return ""; } uint virtualKeyCode = (uint)key; uint scanCode = MapVirtualKey(virtualKeyCode, 0); IntPtr inputLocaleIdentifier = GetKeyboardLayout(0); StringBuilder result = new StringBuilder(); ToUnicodeEx(virtualKeyCode, scanCode, keyboardState, result, (int)5, (uint)0, inputLocaleIdentifier); return result.ToString(); }方法。

count

您将使用带有set修饰符的位置运算符来更新来自查询过滤器的字段匹配。

以下查询会将Bson filter = Filters.elemMatch("daily", and(eq("executionParam1", coll.getexecutionParam1()), eq("executionParam2", coll.getexecutionParam2()), eq("executionParam3", coll.getexecutionParam3()))); long count = this.mongoDailyReportCollection.count(filter);更新为executionParam1。

像

这样的东西

Banana

Mongodb投影不适用于java

1 个答案: