Sqlite:create table success but insert fails

Hi

I am trying to port sqlite3 VFS implementation on freertos with stm32. I
have created an amalgamation with sqlite3 version 3.12 base code.

When I run the below code it runs to create a database and a query "create
a table cars". But when query "insert" is run then fails with following
error:-
error no: 26(SQLITE_NOTADB) 
error: "file is encrypted or is not a database"

I have given following options during compile:
  SQLITE_THREADSAFE=0
  SQLITE_OS_OTHER=1
  SQLITE_OMIT_WAL=1

Any pointer would really help.

Have a sample code as below:

  sqlite3 *db = NULL;
  char *zErrMsg = 0;
  int rc;
  char *sql;


  rc = sqlite3_vfs_register(sqlite3_demovfs(), 1); /* Register a VFS */
  if(rc != SQLITE_OK)
  {
    abort();
  }

  rc = sqlite3_open_v2("testsql.db", &db, SQLITE_OPEN_READWRITE |   
  SQLITE_OPEN_CREATE , "demo" );/* Create a SQL table */
  if( rc )
  {
    abort();
  }

  sql = "PRAGMA journal_mode=OFF";/* Create SQL statement */
  rc = sqlite3_exec(db, sql, NULL, NULL, &zErrMsg);/* Execute SQL statement
*/
  if( rc != SQLITE_OK )
  {
    sqlite3_free(zErrMsg);
    abort();
  }

  sql ="CREATE TABLE Cars(Id INT, Name TEXT, Price INT);" ;/* Create SQL
statement */
  rc = sqlite3_exec(db, sql, NULL, NULL, &zErrMsg);/* Execute SQL statement
*/
  if( rc != SQLITE_OK )
  {
    sqlite3_free(zErrMsg);
    abort();
  }

  sql = "INSERT INTO Cars VALUES(1, 'Audi', 52642);"/* Create SQL statement
*/
      "INSERT INTO Cars VALUES(2, 'Skoda', 9000);";
  rc = sqlite3_exec(db, sql, NULL, NULL, &zErrMsg);/* Execute SQL statement
*/
  if( rc != SQLITE_OK )
  {
    sqlite3_free(zErrMsg);
    abort();
  }

  sql = "SELECT * from Cars";/* Create SQL statement */
  const char* data = "Callback function called";
  rc = sqlite3_exec(db, sql, callback, (void *)data, &zErrMsg);/* Execute
SQL statement */
  if( rc != SQLITE_OK )
  {
    sqlite3_free(zErrMsg);
    abort();
  }
  sqlite3_close(db);