Slide 10.15: Line-by-line anatomy of DB.c (cont.)   Slide 10.17: Line-by-line anatomy of DB.c (cont.)   Home

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

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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: Database access pointer

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.