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.
The values of Informix 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 MONTH

Oracle® MySQL and MariaDB

MySQL and MariadDB support an INTERVAL data type. However, the interval values are used mainly for date/time calculations like:
SELECT NOW() + INTERVAL 5 MINUTE

It is not possible to create a MySQL/MariadDB table column with an interval type.

Solution

The INTERVAL data type and values are converted CHAR(50) column with MySQL.

INTERVAL values can be stored and retrieved from the database. However, interval arithmetics cannot be performed on the database side in SQL statements.

The INTERVAL types translation can be controlled with the following FGLPROFILE entry:
dbi.database.dsname.ifxemul.datatype.interval = { true | false }
For more details see IBM Informix emulation parameters in FGLPROFILE.