如何在MongoDB PHP中减去 [英] How to subtract in mongodb php

问题描述

 $getdataPipeline = array(
            array(
                '$match' => array(
                    'project_id' => array('$in' => $mysql_project_id) // Validating project ID
                ),
                '$match' => array('project_id' => $project_id)
            ),
            array(
                '$group' => array(
                    '_id' => array('pro_id' => '$project_id', 'uid' => '$user_id'),
                    "wh" => array('$subtract' => array(array('$sum' => '$toltal_timein_minutes'), array('$sum' => '$holding_durationin_minutes')))

                ))
        );

运行查询:

  $ValidProjectIdInMongo = $collection->aggregate($getdataPipeline);

我遇到类似的错误

带有消息'localhost:27017的未捕获异常'MongoResultException':异常:未知的组运算符'$ subtract'

Uncaught exception 'MongoResultException' with message 'localhost:27017: exception: unknown group operator '$subtract''

推荐答案

$sum 是要与 $group 一起使用的累加器，因此它必须是所使用的顶级运算符.因此，您的其他操作需要在$sum内进行:

$getdataPipeline = array(
    array(
        '$match' => array('project_id' => $project_id)
    ),
    array(
        '$group' => array(
            '_id' => array('pro_id' => '$project_id', 'uid' => '$user_id'),
            "wh" => array( 
                '$sum' => array( 
                    '$subtract' => array( 
                        '$toltal_timein_minutes', 
                        '$holding_durationin_minutes'
                    ) 
                ) 
            )
        )
    )
);

您可以在此处执行此操作，因为这是基本的减法，但是更复杂的操作通常需要在$group之后的一个单独的$project阶段.

You can do it here because this is basic subtraction, but more complex operations would generally require a separate $project stage after the $group.

还请注意，您$match管道阶段是不正确的，实际上将被解释，就像我在上面重新编写的那样.您可能是在两个条件下都表示$in的条件，这是合乎逻辑的$or.

Also note that yout $match pipeline stage is incorrect and will actually be interpretted just as I have re-written above. You perhaps mean in $in condition for both the possible values, which is a logical $or.

您还可能在字段名称中输入键入错误.

You also have what looks like typing errors in the field names.

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