Question

所以我想验证值是否在集合内。我已经使用 .map 做到了。我的代码如下所示（该字段是嵌套字段）：

  const loopFields = [
    "nested.field1",
    "nested.field2",
    "nested.field3",
    "nested.field4"
  ];

  async function getField() {
    const field = loopFields.map(async (fld, idx) => {
      const result = await Field.findOne({ [fld]: req.body.field });
      if (result) {
        return fld;
      }
    });
    const isFound = await Promise.all(field);
    for (i = 0; i < loopFields.length; i++) {
      if (isFound[i] !== undefined) {
        return true;
      }
    }
  }

const isValid = await getField();

if (!isValid) {
  return res.status(400).send("Field not found");
}

该代码确实有效，但是我正在寻找一种重构它的方法。

Answer 1

动态构建$or子句，并将其传递给find方法，如下所示：

var loopFields = [
    "nested.field1",
    "nested.field2",
    "nested.field3",
    "nested.field4"
];

var fields = loopFields.map(field => {
    var x = {};
    x[field] = req.body.field;
    return x;
})

db.collection.find({ $or: fields });

猫鼬查询FindOne与数组

1 个答案: