Slide 10.16: Line-by-line anatomy of DB.c (cont.)

Line-by-line Anatomy of DB.c (Cont.)


  StrPrintF( buf, "%ld record(s) still locked.", locks );

This function Int16 StrPrintF( Char *s, const Char *formatStr, ... ) implements a subset of the ANSI C sprintf call, which writes formatted output to a string.

s: Pointer to a string into which the results are written
formatStr: Pointer to the format specification string
...: Zero or more arguments to be formatted as specified by formatStr


  DmCloseDatabase( db );

This function Err DmCloseDatabase( DmOpenRef dbP ) closes a database.

dbP

This routine does not unlock any records that were left locked. Records and resources should not be left locked. If a record/resource is left locked, you should not use its reference because the record can disappear during a HotSync operation or if the database is deleted by the user. To prevent the DB from being deleted, you can use DmDatabaseProtect( ) before closing.


  DmNewRecord( db, &index, sizeof( DBRecordType ) )

This function MemHandle DmNewRecord( DmOpenRef dbP, UInt16 *atP, UInt32 size ) returns a handle to a new record in the database and marks the record busy.

dbP: DmOpenRef to open database
atP: Pointer to index where new record should be placed. Specify the value dmMaxRecordIndex to add the record to the end of the database.
size: Size of new record

Both the busy and dirty bits are set for the new record and a unique ID is automatically created. DmReleaseRecord( ) should be called as soon as the caller finishes viewing or editing the record.