The mi_qual_qual() accessor function

Syntax

MI_AM_QUAL_DESC* mi_qual_qual(MI_AM_QUAL_DESC *qualDesc,
   mi_integer n);

qualDesc

Points to the qualification descriptor.

n

Identifies which qualification to retrieve in the expression.

Set n to 0 to retrieve the first qualification descriptor in the array of qualification descriptors. Set n to 1 to retrieve the second qualification descriptor in the array. Increment n by 1 to retrieve each subsequent qualification.

Usage

To determine the number of qualifications in an expression and thus the number of iterations through mi_qual_qual(), first call the mi_qual_nquals() accessor function. If mi_qual_nquals() returns 0, the access method does not call mi_qual_qual() because the access method already knows the address of the qualification descriptor. For a simple qualification, mi_qual_qual() points to the same qualification descriptor as mi_scan_quals().

If mi_qual_nquals() returns a non-zero value, the qualification descriptor combines nested qualifications in a complex expression. The access method can loop through mi_qual_qual() to process each qualification from those that AND or OR combine.

Return values

The pointer that this function returns provides the beginning address of the next qualification from a complex WHERE clause.