SQLite

/*
** Text of a help message
*/
static char zHelp[] =
  ".backup ?DB? FILE      Backup DB (default \"main\") to FILE\n"
  ".bail ON|OFF           Stop after hitting an error.  Default OFF\n"
  ".clone NEWDB           Clone data into NEWDB from the existing database\n"
  ".databases             List names and files of attached databases\n"
  ".dump ?TABLE? ...      Dump the database in an SQL text format\n"
  "                         If TABLE specified, only dump tables matching\n"
  "                         LIKE pattern TABLE.\n"
  ".echo ON|OFF           Turn command echo on or off\n"
  ".exit                  Exit this program\n"
  ".explain ?ON|OFF?      Turn output mode suitable for EXPLAIN on or off.\n"

  ".open ?FILENAME?       Close existing database and reopen FILENAME\n"
  ".output FILENAME       Send output to FILENAME\n"
  ".output stdout         Send output to the screen\n"
  ".print STRING...       Print literal STRING\n"
  ".prompt MAIN CONTINUE  Replace the standard prompts\n"
  ".quit                  Exit this program\n"
  ".read FILENAME         Execute SQL in FILENAME\n"

  ".restore ?DB? FILE     Restore content of DB (default \"main\") from FILE\n"
  ".schema ?TABLE?        Show the CREATE statements\n"
  "                         If TABLE specified, only show tables matching\n"
  "                         LIKE pattern TABLE.\n"
  ".separator STRING      Change separator used by output mode and .import\n"
  ".show                  Show the current values for various settings\n"
  ".stats ON|OFF          Turn stats on or off\n"

    p->cTerm = c;
  }
  if( p->z ) p->z[p->n] = 0;
  return p->z;
}

/*
** Try to transfer data for table zTable.  If an error is seen while
** moving forward, try to go backwards.  The backwards movement won't
** work for WITHOUT ROWID tables.
*/
static void tryToCloneData(
  struct callback_data *p,
  sqlite3 *newDb,
  const char *zTable
){
  sqlite3_stmt *pQuery = 0; 
  sqlite3_stmt *pInsert = 0;
  char *zQuery = 0;
  char *zInsert = 0;
  int rc;
  int i, j, n;
  int nTable = (int)strlen(zTable);
  int k = 0;
  int cnt = 0;
  const int spinRate = 10000;

  zQuery = sqlite3_mprintf("SELECT * FROM \"%w\"", zTable);
  rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
  if( rc ){
    fprintf(stderr, "Error %d: %s on [%s]\n",
            sqlite3_extended_errcode(p->db), sqlite3_errmsg(p->db),
            zQuery);
    goto end_data_xfer;
  }
  n = sqlite3_column_count(pQuery);
  zInsert = sqlite3_malloc(200 + nTable + n*3);
  if( zInsert==0 ){
    fprintf(stderr, "out of memory\n");
    goto end_data_xfer;
  }
  sqlite3_snprintf(200+nTable,zInsert,
                   "INSERT OR IGNORE INTO \"%s\" VALUES(?", zTable);
  i = (int)strlen(zInsert);
  for(j=1; j<n; j++){
    memcpy(zInsert+i, ",?", 2);
    i += 2;
  }
  memcpy(zInsert+i, ");", 3);
  rc = sqlite3_prepare_v2(newDb, zInsert, -1, &pInsert, 0);
  if( rc ){
    fprintf(stderr, "Error %d: %s on [%s]\n",
            sqlite3_extended_errcode(newDb), sqlite3_errmsg(newDb),
            zQuery);
    goto end_data_xfer;
  }
  for(k=0; k<2; k++){
    while( (rc = sqlite3_step(pQuery))==SQLITE_ROW ){
      for(i=0; i<n; i++){

            sqlite3_bind_blob(pInsert, i+1, sqlite3_column_blob(pQuery,i),
                                            sqlite3_column_bytes(pQuery,i),
                                            SQLITE_STATIC);
            break;
          }
        }
      } /* End for */
      rc = sqlite3_step(pInsert);
      if( rc!=SQLITE_OK && rc!=SQLITE_ROW && rc!=SQLITE_DONE ){
        fprintf(stderr, "Error %d: %s\n", sqlite3_extended_errcode(newDb),
                        sqlite3_errmsg(newDb));
      }
      sqlite3_reset(pInsert);
      cnt++;
      if( (cnt%spinRate)==0 ){
        printf("%c\b", "|/-\\"[(cnt/spinRate)%4]);
        fflush(stdout);
      }
    } /* End while */
    if( rc==SQLITE_DONE ) break;
    sqlite3_finalize(pQuery);
    sqlite3_free(zQuery);
    zQuery = sqlite3_mprintf("SELECT * FROM \"%w\" ORDER BY rowid DESC;",
                             zTable);
    rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
    if( rc ){
      fprintf(stderr, "Warning: cannot step \"%s\" backwards", zTable);

      break;

    }
  } /* End for(k=0...) */

end_data_xfer:
  sqlite3_finalize(pQuery);
  sqlite3_finalize(pInsert);
  sqlite3_free(zQuery);
  sqlite3_free(zInsert);
}


/*
** Try to transfer all rows of the schema that match zWhere.  For
** each row, invoke xForEach() on the object defined by that row.
** If an error is encountered while moving forward through the
** sqlite_master table, try again moving backwards.
*/
static void tryToCloneSchema(
  struct callback_data *p,
  sqlite3 *newDb,
  const char *zWhere,
  void (*xForEach)(struct callback_data*,sqlite3*,const char*)
){
  sqlite3_stmt *pQuery = 0;
  char *zQuery = 0;
  int rc;
  const unsigned char *zName;
  const unsigned char *zSql;
  char *zErrMsg = 0;

  zQuery = sqlite3_mprintf("SELECT name, sql FROM sqlite_master"
                           " WHERE %s", zWhere);
  rc = sqlite3_prepare_v2(p->db, zQuery, -1, &pQuery, 0);
  if( rc ){
    fprintf(stderr, "Error: (%d) %s on [%s]\n",
                    sqlite3_extended_errcode(p->db), sqlite3_errmsg(p->db),
                    zQuery);
    goto end_schema_xfer;
  }
  while( (rc = sqlite3_step(pQuery))==SQLITE_ROW ){
    zName = sqlite3_column_text(pQuery, 0);
    zSql = sqlite3_column_text(pQuery, 1);
    printf("%s... ", zName); fflush(stdout);
    sqlite3_exec(newDb, (const char*)zSql, 0, 0, &zErrMsg);
    if( zErrMsg ){
      fprintf(stderr, "Error: %s\nSQL: [%s]\n", zErrMsg, zSql);
      sqlite3_free(zErrMsg);
      zErrMsg = 0;
    }
    if( xForEach ){
      xForEach(p, newDb, (const char*)zName);
    }
    printf("done\n");
  }
  if( rc!=SQLITE_DONE ){
    sqlite3_finalize(pQuery);

                      zQuery);
      goto end_schema_xfer;
    }
    while( (rc = sqlite3_step(pQuery))==SQLITE_ROW ){
      zName = sqlite3_column_text(pQuery, 0);
      zSql = sqlite3_column_text(pQuery, 1);
      printf("%s... ", zName); fflush(stdout);
      sqlite3_exec(newDb, (const char*)zSql, 0, 0, &zErrMsg);
      if( zErrMsg ){
        fprintf(stderr, "Error: %s\nSQL: [%s]\n", zErrMsg, zSql);
        sqlite3_free(zErrMsg);
        zErrMsg = 0;
      }
      if( xForEach ){
        xForEach(p, newDb, (const char*)zName);
      }
      printf("done\n");
    }
  }
end_schema_xfer: