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$tsSecond (aggregation)

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  • Definition
  • Behavior
  • Examples
$tsSecond

New in version 5.1.

Returns the seconds from a timestamp as a long.

$tsSecond syntax:

{ $tsSecond: <expression> }

The expression must resolve to a timestamp.

Tip

See also:

$tsSecond returns:

  • Null if the input expression evaluates to null or refers to a field that is missing.

  • An error if the input expression does not evaluate to a timestamp.

Create a stockSales collection that contains company stock financial market sales:

db.stockSales.insertMany( [
{ _id: 0, symbol: "ABC", saleTimestamp: Timestamp(1622731060, 1) },
{ _id: 1, symbol: "ABC", saleTimestamp: Timestamp(1622731060, 2) },
{ _id: 2, symbol: "DEF", saleTimestamp: Timestamp(1714124193, 1) },
{ _id: 3, symbol: "DEF", saleTimestamp: Timestamp(1714124193, 2) },
{ _id: 4, symbol: "DEF", saleTimestamp: Timestamp(1714124193, 3) }
] )

In the timestamp constructor, the:

The following example uses $tsSecond in a $project pipeline stage to return the seconds from the stock sales saleTimestamp field:

db.stockSales.aggregate( [
{
$project:
{
_id: 0, saleTimestamp: 1, saleSeconds: { $tsSecond: "$saleTimestamp" }
}
}
] )

Example output:

{
saleTimestamp: Timestamp({ t: 1622731060, i: 1 }),
saleSeconds: Long("1622731060")
},
{
saleTimestamp: Timestamp({ t: 1622731060, i: 2 }),
saleSeconds: Long("1622731060")
},
{
saleTimestamp: Timestamp({ t: 1714124193, i: 1 }),
saleSeconds: Long("1714124193")
},
{
saleTimestamp: Timestamp({ t: 1714124193, i: 2 }),
saleSeconds: Long("1714124193")
},
{
saleTimestamp: Timestamp({ t: 1714124193, i: 3 }),
saleSeconds: Long("1714124193")
}

The example in this section uses $tsSecond in a change stream cursor to monitor changes to a collection.

Create a change stream cursor on a collection named cakeSales that you will see later in this section:

cakeSalesCursor = db.cakeSales.watch( [
{
$addFields: {
clusterTimeSeconds: { $tsSecond: "$clusterTime" }
}
}
] )

In the example, the:

Create a cakeSales collection that contains cake sales in the states of California (CA) and Washington (WA):

db.cakeSales.insertMany( [
{ _id: 0, type: "chocolate", orderDate: new Date("2020-05-18T14:10:30Z"),
state: "CA", price: 13, quantity: 120 },
{ _id: 1, type: "chocolate", orderDate: new Date("2021-03-20T11:30:05Z"),
state: "WA", price: 14, quantity: 140 },
{ _id: 2, type: "vanilla", orderDate: new Date("2021-01-11T06:31:15Z"),
state: "CA", price: 12, quantity: 145 },
{ _id: 3, type: "vanilla", orderDate: new Date("2020-02-08T13:13:23Z"),
state: "WA", price: 13, quantity: 104 },
{ _id: 4, type: "strawberry", orderDate: new Date("2019-05-18T16:09:01Z"),
state: "CA", price: 41, quantity: 162 },
{ _id: 5, type: "strawberry", orderDate: new Date("2019-01-08T06:12:03Z"),
state: "WA", price: 43, quantity: 134 }
] )

To monitor the cakeSales collection changes, use cakeSalesCursor. For example, to obtain the next document from cakeSalesCursor, use the next() method:

cakeSalesCursor.next()

The following example output shows the insert details for the first document added to the cakeSales collection. The clusterTimeSeconds field contains the seconds from the clusterTime field.

_id: {
_data: '82613A4A51000000032B022C0100296E5A100495189B4131584C56AC8BA9D540799F23461E5F696400290004'
},
operationType: 'insert',
clusterTime: Timestamp({ t: 1631210065, i: 3 }),
fullDocument: {
_id: 0,
type: 'chocolate',
orderDate: ISODate("2020-05-18T14:10:30.000Z"),
state: 'CA',
price: 13,
quantity: 120
},
ns: { db: 'test', coll: 'cakeSales' },
documentKey: { _id: 0 },
clusterTimeSeconds: 1631210065
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