- All Superinterfaces:
Serializable
- All Known Implementing Classes:
DayToSecond
,YearToMonth
,YearToSecond
java.sql.Interval
data type.
JDBC lacks an important data type that is present in most SQL databases:
INTERVAL
. The SQL:2008 standard states that there are two types
of intervals:
4.6.3 IntervalsThere are two classes of intervals. One class, called year-month intervals, has an express or implied datetime precision that includes no fields other than YEAR and MONTH, though not both are required. The other class, called day-time intervals, has an express or implied interval precision that can include any fields other than YEAR or MONTH.
INTERVAL
can be combined with date time data types according to
the following operation table:
Operand 1 | Operator | Operand 2 | Result Type |
---|---|---|---|
Datetime | – | Datetime | Interval |
Datetime | + or – | Interval | Datetime |
Interval | + | Datetime | Datetime |
Interval | + or – | Interval | Interval |
Interval | * or / | Numeric | Interval |
Numeric | * | Interval | Interval |
Interval implementations can be expected to also also extend Number
.
Note: only a few databases actually support this data type on its own. You
can still use it for date time arithmetic in other databases, though, through
Field.add(Field)
and Field.sub(Field)
Databases that have
been observed to natively support INTERVAL
data types are:
These dialects have been observed to partially support INTERVAL
data types in date time arithmetic functions, such as
TIMESTAMPADD
, and TIMESTAMPDIFF
:
- Author:
- Lukas Eder
-
Method Details
-
neg
Interval neg()Negate the interval (change its sign) -
abs
Interval abs()Get the absolute value of the interval (set its sign to positive) -
getSign
int getSign()The sign of the interval- Returns:
1
for positive or zero,-1
for negative
-
doubleValue
double doubleValue()- See Also:
Number.doubleValue()
-
floatValue
float floatValue()- See Also:
Number.floatValue()
-
longValue
long longValue()- See Also:
Number.longValue()
-
intValue
int intValue()- See Also:
Number.intValue()
-
byteValue
byte byteValue()- See Also:
Number.byteValue()
-
shortValue
short shortValue()- See Also:
Number.shortValue()
-
toDuration
Duration toDuration()Get a duration representation of this interval.There is an obvious
Duration
representation forDayToSecond
intervals. If the interval containsYearMonth
information, then the corresponding duration will use:- 1 year = 365.25 days
- 1 month = 30 days
This corresponds to PostgreSQL's
EXTRACT(EPOCH FROM my_interval)
behaviour.
-