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Extending HCL OneDB™Beyond standard relational database objects, HCL OneDB™ can be extended to handle specialized data types, access methods, routines, and other objects. HCL OneDB™ includes many built-in extensions that are fully integrated in the database server. HCL OneDB™ also provides DataBlade® modules, which are packages of extended database objects for a particular purpose and that are installed separately from the database server. Alternatively, you can create your own user-defined objects for HCL OneDB™.
Creating extensionsYou can create user-defined data types, routines, access methods, and other database objects to suit your needs. You can use application programming interfaces to write user-defined routines and applications that access data in HCL OneDB™ databases.
DataBlade® API Function ReferenceThe HCL OneDB™ DataBlade® API Function Reference describes the DataBlade® API functions and the subset of functions that the DataBlade® API supports.
Function descriptionsThis section gives comprehensive reference information about the functions that are valid within DataBlade® API modules. It lists the function descriptions in alphabetical order, with syntax, usage information, and return values for the functions.
The dtsub() functionThe dtsub() function subtracts one datetime value from another. The result is an interval value.

The dtsub() function

The dtsub() function subtracts one datetime value from another. The result is an interval value.

Syntax

mint dtsub(d1, d2, inv)
   dtime_t *d1, *d2;
   intrvl_t *inv;

d1: A pointer to an initialized datetime variable.
d2: A pointer to an initialized datetime variable.
inv: A pointer to an interval variable to contain the result.

Usage

The dtsub() function subtracts the datetime value d2 from d1 and stores the interval result in inv. The result can be either a positive or a negative value. If necessary, the function extends d2 to match the qualifier for d1, before the subtraction.

Initialize the qualifier for inv with a value in either the year to month or day to fraction(5) classes. When d1 contains fields in the day to fraction class, the interval qualifier must also be in the day to fraction class.

Return values

0: The subtraction was successful.
<0: An error occurred while performing the subtraction.