Skip to content

Calculate month and quarter for timestampdiff based on date and clock time values #3409

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
angelamayxie wants to merge 5 commits into
base: main
Choose a base branch
from
Draft

Calculate month and quarter for timestampdiff based on date and clock time values #3409

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
1b74d4a
rewrite month diff
angelamayxie Jan 31, 2026
0eea689
refactor month diff into reusable function for year and quarter
angelamayxie Jan 31, 2026
df431af
add tests
angelamayxie Jan 31, 2026
f301126
add tests for timestamp diff between smallest and largest timestamps
angelamayxie Jan 31, 2026
e0b9292
rename monthDiff to monthsDiff
angelamayxie Jan 31, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
98 changes: 97 additions & 1 deletion enginetest/queries/function_queries.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -911,7 +911,7 @@ var FunctionQueryTests = []QueryTest{
Query: "SELECT TIMESTAMPDIFF(SECOND, null, '2007-12-31 00:00:00');",
Expected: []sql.Row{{nil}},
},
// https://github.com/dolthub/dolt/issues/10393
// TIMESTAMPDIFF YEAR tests https://github.com/dolthub/dolt/issues/10393
{
Query: "SELECT TIMESTAMPDIFF(YEAR, DATE '2011-07-05', DATE '2026-07-04')",
Expected: []sql.Row{{14}},
Expand All @@ -936,6 +936,102 @@ var FunctionQueryTests = []QueryTest{
Query: "SELECT TIMESTAMPDIFF(YEAR, DATE '2026-07-03', DATE '2025-07-04')",
Expected: []sql.Row{{0}},
},
{
Query: `select timestampdiff(year, "0050-01-01", "2020-01-01");`,
Expected: []sql.Row{{1970}},
},
{
Query: "select timestampdiff(year, '0000-01-01', '9999-12-31 23:59:59.999999');",
Expected: []sql.Row{{9999}},
},
// TIMESTAMPDIFF MONTH tests https://github.com/dolthub/dolt/issues/10393
{
Query: `select timestampdiff(year, "2000-12-25", "2020-2-20");`,
Expected: []sql.Row{{19}},
},
{
Query: "SELECT TIMESTAMPDIFF(month, DATE '2011-07-05', DATE '2026-07-04')",
Expected: []sql.Row{{179}},
},
{
Query: "SELECT TIMESTAMPDIFF(month, DATE '2026-07-04', DATE '2011-07-05')",
Expected: []sql.Row{{-179}},
},
{
Query: `select timestampdiff(month, "2000-12-25", "2020-2-20");`,
Expected: []sql.Row{{229}},
},
{
Query: `select timestampdiff(month, "0050-01-01", "2020-01-01");`,
Expected: []sql.Row{{23640}},
},
{
Query: "select timestampdiff(month, '0000-01-01', '9999-12-31 23:59:59.999999');",
Expected: []sql.Row{{119999}},
},
// TIMESTAMPDIFF QUARTER tests https://github.com/dolthub/dolt/issues/10393
{
Query: "SELECT TIMESTAMPDIFF(quarter, DATE '2011-07-05', DATE '2026-07-04')",
Expected: []sql.Row{{59}},
},
{
Query: "SELECT TIMESTAMPDIFF(quarter, DATE '2026-07-04', DATE '2011-07-05')",
Expected: []sql.Row{{-59}},
},
{
Query: `select timestampdiff(quarter, "0050-01-01", "2020-01-01");`,
Expected: []sql.Row{{7880}},
},
{
Query: `select timestampdiff(quarter, "2000-12-25", "2020-2-20");`,
Expected: []sql.Row{{76}},
},
{
Query: "select timestampdiff(quarter, '0000-01-01', '9999-12-31 23:59:59.999999');",
Expected: []sql.Row{{39999}},
},
{
// https://github.com/dolthub/dolt/issues/10397
Skip: true,
// might need to change first date to 0001-01-01 since 0000 is a leap year in Go but not in MySQL
Query: "select timestampdiff(microsecond, '0000-01-01', '9999-12-31 23:59:59.999999');",
Expected: []sql.Row{{315569433599999999}},
},
{
// https://github.com/dolthub/dolt/issues/10397
Skip: true,
// might need to change first date to 0001-01-01 since 0000 is a leap year in Go but not in MySQL
Query: "select timestampdiff(second, '0000-01-01', '9999-12-31 23:59:59.999999');",
Expected: []sql.Row{{315569433599}},
},
{
// https://github.com/dolthub/dolt/issues/10397
Skip: true,
// might need to change first date to 0001-01-01 since 0000 is a leap year in Go but not in MySQL
Query: "select timestampdiff(minute, '0000-01-01', '9999-12-31 23:59:59.999999');",
Expected: []sql.Row{{5259490559}},
},
{
// https://github.com/dolthub/dolt/issues/10397
Skip: true,
// might need to change first date to 0001-01-01 since 0000 is a leap year in Go but not in MySQL
Query: "select timestampdiff(hour, '0000-01-01', '9999-12-31 23:59:59.999999');",
Expected: []sql.Row{{87658175}},
},
{
// https://github.com/dolthub/dolt/issues/10397
Skip: true,
// might need to change first date to 0001-01-01 since 0000 is a leap year in Go but not in MySQL
Query: "select timestampdiff(day, '0000-01-01', '9999-12-31 23:59:59.999999');",
Expected: []sql.Row{{3652423}},
},
{
// https://github.com/dolthub/dolt/issues/10397
Skip: true,
// might need to change first date to 0001-01-01 since 0000 is a leap year in Go but not in MySQL
Query: "select timestampdiff(week, '0000-01-01', '9999-12-31 23:59:59.999999');",
Expected: []sql.Row{{521774}},
},
// TRIM Function Tests
{
Query: `SELECT TRIM(mytable.s) AS s FROM mytable`,
Expand Down
101 changes: 38 additions & 63 deletions sql/expression/function/time_math.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -672,6 +672,10 @@ func (t *TimestampDiff) Eval(ctx *sql.Context, row sql.Row) (interface{}, error)
date1 := expr1.(time.Time)
date2 := expr2.(time.Time)

if date1.Equal(date2) {
return 0, nil
}

diff := date2.Sub(date1)

var res int64
Expand All @@ -689,74 +693,45 @@ func (t *TimestampDiff) Eval(ctx *sql.Context, row sql.Row) (interface{}, error)
case "week":
res = int64(diff.Hours() / (24 * 7))
case "month":
// TODO: this calculation is not correct. Not every month is 30 days https://github.com/dolthub/dolt/issues/10393
res = int64(diff.Hours() / (24 * 30))
if res > 0 {
if date2.Day()-date1.Day() < 0 {
res -= 1
} else if date2.Hour()-date1.Hour() < 0 {
res -= 1
} else if date2.Minute()-date1.Minute() < 0 {
res -= 1
} else if date2.Second()-date1.Second() < 0 {
res -= 1
}
}
res = monthsDiff(date1, date2)
case "quarter":
// TODO: this calculation is not correct. Not every month is 30 days https://github.com/dolthub/dolt/issues/10393
monthRes := int64(diff.Hours() / (24 * 30))
if monthRes > 0 {
if date2.Day()-date1.Day() < 0 {
monthRes -= 1
} else if date2.Hour()-date1.Hour() < 0 {
monthRes -= 1
} else if date2.Minute()-date1.Minute() < 0 {
monthRes -= 1
} else if date2.Second()-date1.Second() < 0 {
monthRes -= 1
}
}
res = monthRes / 3
res = monthsDiff(date1, date2) / 3
case "year":
if diff == 0 {
return 0, nil
}
negate := false
before := date1
after := date2
if diff < 0 {
negate = true
before = date2
after = date1
}

beforeYear, beforeMonth, beforeDay := before.Date()
afterYear, afterMonth, afterDay := after.Date()
yearDiff := afterYear - beforeYear
if beforeMonth > afterMonth {
yearDiff -= 1
} else if beforeMonth == afterMonth {
if beforeDay > afterDay {
yearDiff -= 1
} else if beforeDay == afterDay {
beforeHour, beforeMin, beforeSec := before.Clock()
afterHour, afterMin, afterSec := after.Clock()
secondDiff := (afterHour-beforeHour)*3600 + (afterMin-beforeMin)*60 + (afterSec - beforeSec)
if secondDiff < 0 {
yearDiff -= 1
} else if secondDiff == 0 && before.Nanosecond() > after.Nanosecond() {
yearDiff -= 1
}
}
}

res = int64(yearDiff)
if negate {
res = -res
}
res = monthsDiff(date1, date2) / 12
default:
return nil, errors.NewKind("invalid interval unit: %s").New(unit)
}

return res, nil
}

func monthsDiff(date1, date2 time.Time) int64 {
sign := 1
before := date1
after := date2
if before.After(after) {
sign = -1
before = date2
after = date1
}

beforeYear, beforeMonth, beforeDay := before.Date()
afterYear, afterMonth, afterDay := after.Date()
yearDiff := afterYear - beforeYear
monthDiff := int64(afterMonth) - int64(beforeMonth)

if beforeDay > afterDay {
monthDiff -= 1
} else if beforeDay == afterDay {
beforeHour, beforeMin, beforeSec := before.Clock()
afterHour, afterMin, afterSec := after.Clock()
secondDiff := (afterHour-beforeHour)*3600 + (afterMin-beforeMin)*60 + (afterSec - beforeSec)
if secondDiff < 0 {
monthDiff -= 1
} else if secondDiff == 0 && before.Nanosecond() > after.Nanosecond() {
monthDiff -= 1
}
}

return int64(sign) * (int64(yearDiff*12) + monthDiff)
}
Loading