Question

如果我在SQL中编写它，那将是（某种程度上）：

SELECT *
FROM request req, response res
WHERE req.suites_test=res.key    # join
  AND res.version='2.0.b1662.5'  # extra conditions
  AND req.suites_id='58762c40664df86d2069e2c9'

在MongoDB中，我可以这样做：

# a join between request and response 
db.response.aggregate([{$lookup: {from: "request", localField: "key", foreignField: "suites.test", as: "matching"} } ])

# find all requests that match a condition
db.request.find( { "suites.id": ObjectId("58762c40664df86d2069e2c9") } )

# find all responses that match a condition
db.response.find( { "version": "2.0.b1662.5" } )

如何在一个MongoDB查询中组合三个？

Answer 1

有许多类似的重复，但我找不到完全匹配的副本。所以，我根据OP的要求添加答案。

根据您的个人查询，您只需要包含响应的$match阶段（$lookup之前）和请求（$unwind之后的$lookup）汇总管道中的集合。像下面的东西。

db.response.aggregate([{
    $match: {
        "version": "2.0.b1662.5"
    }
}, {
    $lookup: {
        from: "request",
        localField: "key",
        foreignField: "suites.test",
        as: "matching"
    }
}, {
    $unwind: "$matching"
}, {
    $match: {
        "matching.id": ObjectId("58762c40664df86d2069e2c9")
    }
}])

如何结合where子句和join？

1 个答案: