[SQLite3] 파일로 저장된 DB를 메모리DB로 로드

(From: http://blog.daum.net/_blog/BlogView.do?blogid=0Idq4&articleno=8429408#ajax_history_home)

 

다음은 "파일로 저장된 SQLite3 데이터베이스를 메모리 데이터베이스 (:memory:)로 로드하는 방법"에 대해서 설명하고 있습니다.

이와 관련된 좀 더 자세한 내용은 http://www.sqlite.org/backup.html 를 참고하시면 됩니다.

 

1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <assert.h>
4 #include "sqlite3.h"
5
6 #pragma warning(disable:4996)
7
8 int LoadDatabase(sqlite3 *memDb, const char *zFilename)
9 {
10 int rc; /* Function return code */
11 sqlite3 *fileDB; /* Database connection opened on zFilename */
12 sqlite3_backup *pBackup; /* Backup object used to copy data */
13
14 /* Open the database file identified by zFilename. Exit early if this fails
15 ** for any reason. */
16 rc = sqlite3_open(zFilename, &fileDB);
17 if( rc==SQLITE_OK ){
18
19 /* Set up the backup procedure to copy from the "main" database of
20 ** connection pFile to the main database of connection pInMemory.
21 ** If something goes wrong, pBackup will be set to NULL and an error
22 ** code and message left in connection pTo.
23 **
24 ** If the backup object is successfully created, call backup_step()
25 ** to copy data from pFile to pInMemory. Then call backup_finish()
26 ** to release resources associated with the pBackup object. If an
27 ** error occured, then an error code and message will be left in
28 ** connection pTo. If no error occured, then the error code belonging
29 ** to pTo is set to SQLITE_OK.
30 */
31 pBackup = sqlite3_backup_init(memDb, "main", fileDB, "main");
32 if( pBackup ){
33 (void)sqlite3_backup_step(pBackup, -1);
34 (void)sqlite3_backup_finish(pBackup);
35 }
36 rc = sqlite3_errcode(memDb);
37 }
38
39 /* Close the database connection opened on database file zFilename
40 ** and return the result of this function. */
41 (void)sqlite3_close(fileDB);
42 return rc;
43 }
44
45 int main(int argc, char **argv)
46 {
47 sqlite3 *db = NULL;
48 sqlite3_stmt *stmt = NULL;
49
50 assert(sqlite3_open_v2(":memory:", &db, SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, NULL) == SQLITE_OK);
51 assert(LoadDatabase(db, "./test.db") == SQLITE_OK);
52 assert(sqlite3_prepare(db, "select id, name from address;", -1, &stmt, NULL) == SQLITE_OK);
53
54 while ( sqlite3_step(stmt) == SQLITE_ROW )
55 {
56 // do something with column
57 sqlite3_column_int(stmt, 0);
58 sqlite3_column_text(stmt, 1);
59 }
60
61 assert(sqlite3_close(db) == SQLITE_OK);
62 return 0;
63 }