DB->set_dup_compare API Ref

#include <db.h>

int DB->set_dup_compare(DB *db, int (*dup_compare_fcn)(DB *, const DBT *, const DBT *));


Description: DB->set_dup_compare

Set the duplicate data item comparison function. The comparison function is called whenever it is necessary to compare a data item specified by the application with a data item currently stored in the database. Calling DB->set_dup_compare implies calling DB->set_flags with the DB_DUPSORT flag.

If no comparison function is specified, the data items are compared lexically, with shorter data items collating before longer data items.

The DB->set_dup_compare method may not be called after the DB->open method is called. If the database already exists when DB->open is called, the information specified to DB->set_dup_compare must be the same as that historically used to create the database or corruption can occur.

The DB->set_dup_compare method returns a non-zero error value on failure and 0 on success.

Parameters
dup_compare_fcn

Errors

The DB->set_dup_compare method may fail and return one of the following non-zero errors:


EINVAL


Class DB
See Also Databases and Related Methods

APIRef

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