Moves the cursor to the record that most closely matches the current key.
Call GotoNearest to position the cursor on the record that is either the exact record specified by the current key values in the key buffer, or on the first record whose values exceed those specified.
KeyExclusive determines which records are considered part of a search range.
Before calling GotoNearest, an application must specify key values by calling SetKey or EditKey to put the dataset is dsSetKey state, and then use FieldByName to populate the key buffer property with search values.
Delphi 7 and prior has poor support for int64 values in variant type. This means that you'll be unable to use Locate() and similar methods with such fields. Lookup fields will not work proper too due to their dependence on Locate() method. Please update your IDE to BDS 2006 or don't use bigint (int8) and bigserial datatypes for keys and indexes if you need to use them in lookup fields.