How to save SQLite Database in memory to file?

[jacdelad]

Hi,
I found several examples on how to use sqlite in memory, using ":memory:" as database. But can I save the database to a file (and reload it into memory)? I mean other than creating an identical database structure and copy the data. I want to prevent to write every single update to disk and want to flush it, when the operations are done.

[Bisonte]

Infratec does it before...

https://www.purebasic.fr/english/viewto ... 86#p572886

[jacdelad]

Ah thanks! I obviously used the wrong keywords for searching and didn't think copying it to *memory.

[justjake]

I had problems- in pre 6.11 I got a memory error with 6.11, the code just crashed. (with or without using p-utf8)
here's the version I ended up with.
I originally used utf8() but why do two function calls(utf8() & freememory()) to achieve the same thing with a datasection?
(portion of my sqlite3 library)

Code: Select all

DeclareModule sqlite3
  Declare backup( srcNum, dstNum )
EndDeclareModule
Module sqlite3
  EnableExplicit
  UseSQLiteDatabase()
  ImportC ""
    sqlite3_backup_init(destID, *zDestName, sourceID, *zSourceName)
    sqlite3_backup_step(backupHandle, nPage)
    sqlite3_backup_finish(backupHandle)
  EndImport
  
  #backupALL = -1
  #sqlite3_ok = 0
  
  DataSection 
    asciiMain:
    Data.a 'm', 'a', 'i', 'n', 0 ; "p-utf8" didn't work for me. Caused memory error, on 6.11 just a crash.
  EndDataSection
  
  Procedure backup(srcNum, dstNum)  
    Protected success, backupHandle
    
    If IsDatabase(srcNum) And IsDatabase(dstNum)
      backupHandle = sqlite3_backup_init( DatabaseID(dstNum), ?asciiMain, DatabaseID(srcNum), ?asciiMain )
      If backupHandle
        sqlite3_backup_step( backupHandle, #backupALL )
        success = Bool( sqlite3_backup_finish(backupHandle) = #sqlite3_ok )
      EndIf
    EndIf
    ProcedureReturn success
  EndProcedure
EndModule

[Captn. Jinguji]

Anything wrong with simply using :

DatabaseUpdate( #DB_YTCS, "Vacuum DB_MEM into '.\gaga.s3db' " )

??

[infratec]

No, that's perfect.

https://sqlite.org/lang_vacuum.html