INTERVAL data type
Informix®
Informix provides the INTERVAL data type to store a value that represents a
span of time.
INTERVAL types are divided into two classes:- year-month intervals. For example:
INTERVAL YEAR(5) TO MONTH - day-time intervals. For example:
INTERVAL DAY(9) TO SECOND
INTERVAL columns can be defined with various time units, by specifying a
start and end qualifier. For example, you can define an interval to store a number of hours and
minutes with INTERVAL HOUR(n) TO MINUTE, where
n defines the maximum number of digits for the hours unit.INTERVAL can be represented with a
character string literal, or as INTERVAL()
literals:'-9834 15:45:12.345' -- an INTERVAL DAY(6) TO FRACTION(3)
'7623-11' -- an INTERVAL YEAR(9) TO MONTH
INTERVAL(18734:45) HOUR(5) TO MINUTE
INTERVAL(-7634-11) YEAR(5) TO MONTHORACLE
ORACLE provides an INTERVAL data type similar to Informix, implementing two classes (YEAR TO MONTH and
DAY TO SECOND).
However, Oracle's intervals cannot be defined with a time units different from the two interval
classes. For example, you cannot define an INTERVAL HOUR TO MINUTE in Oracle.
INTERVAL DAY TO SECOND(n) contains the fractional part of seconds
and therefore is equivalent to the Informix
INTERVAL DAY TO FRACTION(n) type.Solution
Informix INTERVAL YEAR(n) TO MONTH
data is stored in Oracle INTERVAL YEAR(n) TO MONTH columns. These data types are
equivalent.
Informix INTERVAL DAY(n) TO
FRACTION(p) data is stored in Oracle INTERVAL DAY(n) TO SECOND(p) columns.
These data types are equivalent.
Other Informix INTERVAL types must be
stored in CHAR() columns, because the high qualifier precision cannot be specified
with Oracle INTERVALs. For example, Informix INTERVAL HOUR(5) TO MINUTE has no native equivalent in Oracle.
INTERVAL types translation can be controlled with the following FGLPROFILE
entry:dbi.database.dsname.ifxemul.datatype.interval = { true | false }