MongoDB : Insert and Update in an array - php

Question

I have "_id" and "ProductLot". How can I Update Qty "0" to "1 " in the Lot array if ProductLot if present or append a new Lot element if it is not present?
"_id" : ObjectId("5462e44c599e5c6c1300000a"),
"LocationName" : "Putaway",
"Owner" : "",
"Status" : "1",
"Scrap" : "0",
"Lot" : [{
"Qty" :"6",
"ProductLot" : ObjectId("5462dbd9599e5c200e000000"),
"Product" : ObjectId("543ca7be4cf59d400c000004"),
"Movement" :[ {"OriginId" : "266",Qty:2,Type:"DN"},
{"OriginId" : "267" , Qty:1 , Type:"DN"},
{"OriginId" : "2" , Qty:3 , Type:"IM"},
]
},
{
"Qty" :"0",
"ProductLot" : ObjectId("5462dbd9599e5c200e000003"),
"Product" : ObjectId("543ca7be4cf59d400c000004"),
"Movement" :[ {"OriginId" : "266",Qty:2,Type:"DN"},
{"OriginId" : "267" , Qty:1 , Type:"DN"},
{"OriginId" : "2" , Qty:-3 , Type:"IM"},
]
}]
}
EG: I have "ProductLot" : ObjectId("5462dbd9599e5c200e000000") present in array so it should update qty 0 to 1; however, "ProductLot" : ObjectId("5462dbd9599e5c200e00000a") is not available in array so that should append a new element to the array.
PHP code, which is not updating creating appending array at every time:
$inventoryId = new \MongoId($_POST["inventoryid"]);
$productLotId = new \MongoId($invlotid);
$originId = $_POST['id'];
//$lotcontent = [ /* whatever this looks like */ ];
$lotcontent = array(
'Qty' => $invqty,
'ProductLot' => new \MongoId($invlotid),
'Product'=>$invproduct,
'Movement'=> array(
array(
'OriginId' => $_POST['id'],
'Qty' => $invqty,
'Type'=> 'DN',
), )
);
$invcolname = 'Inventory';
$result = $mongo->$dbname->$invcolname->update(
// Match an inventory without the specific ProductLot/OriginId element
array(
'_id' => $inventoryId,
'Lot' => array(
'$not' => array(
'$elemMatch' => array(
'ProductLot' => $productLotId,
//'OriginId' => $originId,
),
),
),
),
// Append a new element to the Lot array field
array('$push' => array( 'Lot' => $lotcontent ))
);
$movementcontent = array(
'OriginId' => $_POST['id'],
'Qty' => $invqty,
'Type'=> 'DN',
);
$result = $mongo->$dbname->$invcolname->update(
// Match an inventory without the specific ProductLot/OriginId element
array(
'_id' => $inventoryId,
'Lot' => array(
//'$not' => array(
'$elemMatch' => array(
'ProductLot' => $productLotId,
'Movement'=>array(
'$not' => array(
'$elemMatch' => array(
'OriginId' => $originId,
)
)
)
),
// ),
),
),
// Append a new element to the Lot.Movement array field
array('$push' => array( 'Lot.$.Movement' => $movementcontent ))
);
$result = $mongo->$dbname->$invcolname->update(
// Match an inventory with a specific ProductLot/OriginId element
array(
'_id' => $inventoryId,
'Lot' => array(
'$elemMatch' => array(
'ProductLot' => $productLotId,
//'OriginId' => $originId,
'Movement'=>array(
'$elemMatch' => array(
'OriginId' => $originId,
)
)
),
),
),
// Update the "Qty" field of the first array element matched (if any)
//array( '$set' => array( 'Lot.$.Qty' => 'Updated' )),
array( '$set' => array( 'Lot.$.Movement.$.Qty' => $invqty )),
array('upsert' => true));
Please anyone help me to resolve this?

Answer 1

Using $addToSet is problematic in this case, because the following lot elements would be considered different:
{
"Qty" :0,
"ProductLot" : ObjectId("5462dbd9599e5c200e000003"),
"Product" : ObjectId("543ca7be4cf59d400c000004"),
"OriginId" : "266"
}
{
"Qty" :5,
"ProductLot" : ObjectId("5462dbd9599e5c200e000003"),
"Product" : ObjectId("543ca7be4cf59d400c000004"),
"OriginId" : "266"
}
The first element is likely what you would be adding (either with quantity 0 or 1), and the second element would be the same logical lot element, just with an incremented quantity. If the latter element already existed in the array, I imagine you'd like for your application to increment the quantity from 5 to 6 instead of adding the first element, which is essentially a duplicate.
We definitely need two updates here, but I would propose the following:
// Let's assume the following identifiers...
$inventoryId = new MongoId($_POST['inventoryid']);
$productLotId = new MongoId($invlotid);
$originId = new MongoId($_POST['id']);
$lotcontent = [ /* whatever this looks like */ ];
$result = $collection->update(
// Match an inventory without the specific ProductLot/OriginId element
[
'_id' => $inventoryId,
'Lot' => [
'$not' => [
'$elemMatch' => [
'ProductLot' => $productLotId,
'OriginId' => $originId,
],
],
],
],
// Append a new element to the Lot array field
[ '$push' => [ 'Lot' => $lotcontent ] ]
);
MongoCollection::update() will return a result document with an n field indicating the number of affected documents. Since we aren't using the multiple option and are also matching at most one document by _id, we can expect n to be either 0 or 1. If n was 0, we either couldn't find an inventory document with that _id or we found one but it already had a Lot element with the product and origin identifiers (i.e. our $elemMatch criteria matched something, invalidating our negation). If n was 1, that means we found the inventory document, it did not contain a matching Lot element, and we appended it (i.e. our job is done).
Assuming n was 0, we should issue another update and attempt to increment the quantity:
$result = $collection->update(
// Match an inventory with a specific ProductLot/OriginId element
[
'_id' => $inventoryId,
'Lot' => [
'$elemMatch' => [
'ProductLot' => $productLotId,
'OriginId' => $originId,
],
],
],
// Update the "Qty" field of the first array element matched (if any)
[ '$inc' => [ 'Lot.$.Qty' => 1 ] ]
);
Here, I'm using the $ positional update operator to access a specific array element that was matched in the criteria. This allows us to craft an $inc without worrying about the index of the matched element.
Again, we can check $result['n'] here. If it's still 0, then we can assume that no document matches our _id (a completely separate error). But if n is 1 at this point, we successfully incremented the quantity and our job is done.