Details
Description
$dateFromString now supports the %j format specifier, "Day of Year", which allows a user to parse a date from a string containing only the year and a number to indicate which day it is of that year.
Note that %j counts the days from 0-355, not 1-356.
Description of Linked Ticket
The $dateFromString Format Specifiers don't include the strftime %j modifier which is used to decode the day of the year as a decimal number (range 001 to 366).
It appears that this modifier is understood as part of kDateToStringFormatMap from timelib's TIMELIB_FORMAT_DAY_OF_YEAR when converting from a date to a string, but not from a string to a date.
For example:
db.foo.drop()
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db.foo.insert({ _id: 1, d: "2020-194-14:24:45.463" }); |
db.foo.aggregate( [ {
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$project: {
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date: {
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$dateFromString: {
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dateString: "%d", |
format: "%Y-%j-%H:%M:%S.%L" |
}
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}
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}
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} ] )
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// "errmsg" : "Failed to optimize pipeline :: caused by :: Invalid format character '%j' in format string", |
Note that for the above we were able to work around this limitation as follows:
db.foo.drop()
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db.foo.insert({ _id: 1, d: "2020-194-14:24:45.463" }); |
db.foo.aggregate([
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{ $project: {
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date: {
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$let: {
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vars: {
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parts: { $split: [ "$d", "-" ] } |
},
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in: { |
$add: [
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{ $toDate: { $concat: [
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{ $arrayElemAt: [ "$$parts", 0 ] }, |
"-01-01T", |
{ $arrayElemAt: [ "$$parts", 2 ] } ] |
} },
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{ $multiply: [
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{ $subtract: [
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{ $toInt: { $arrayElemAt: [ "$$parts", 1 ] } }, |
1 ] }, 86400000 ] }
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]
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}
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}
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}
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}}
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]);
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// { "_id" : 1, "date" : ISODate("2020-07-12T14:24:45.463Z") } |
Attachments
Issue Links
- documents
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SERVER-50336 $dateFromString support for additional format specifiers (such as "%j" for day of year)
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- Closed
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