The mi_fp_rettype() function
The mi_fp_rettype() accessor function obtains the type identifier for the data type of a return value of a user-defined function from its associated MI_FPARAM structure.
Syntax
MI_TYPEID *mi_fp_rettype(fparam_ptr, ret_pos)
MI_FPARAM *fparam_ptr;
mi_integer ret_pos;
- fparam_ptr
- A pointer to the associated MI_FPARAM structure.
- ret_pos
- The index position into the return-type array for the return value
whose type identifier you want. For user-defined functions, the only
valid value is
0
.
Valid in client LIBMI application? | Valid in user-defined routine? |
---|---|
Yes | Yes |
Usage
The mi_fp_rettype() function
obtains the type identifier of the routine return value at position ret_pos from
the MI_FPARAM structure that fparam_ptr references.
The type identifier is an integer value that indicates a particular
data type. The MI_FPARAM structure stores information about
the type identifiers of function return values in the zero-based return-type
array. To obtain information about the nth return value, use
a ret_pos value of n
-1
. For example,
the following call to mi_fp_rettype() sets the
type identifier for the first return value of the my_func() user-defined
function, with which fparam1 is associated: mi_integer my_func(..., fparam1)
...
MI_FPARAM *fparam1;
{
MI_TYPEID *ret_type;
...
ret_type = mi_fp_rettype(fparam1, 0);
Important: C user-defined functions always have only one return
value.
For more information about return-value information in an MI_FPARAM structure, see the Informix® DataBlade® API Programmer's Guide.
Return values
- An MI_TYPEID pointer
- A pointer to the type identifier of the return value at position ret_pos.
- NULL
- The function was not successful.