sqlite3* db; sqlite3_open("example.db", &db); sqlite3_stmt* stmt; sqlite_prepare_v2(db, "SELECT * FROM users", -1, &stmt, NULL); while (sqlite3_step(stmt) == SQLITE_ROW) { // process the record here } sqlite3_finalize(stmt); sqlite3_close(db);
MYSQL_RES* result; MYSQL_ROW row; MYSQL* conn; mysql_init(conn); mysql_real_connect(conn, "localhost", "user", "password", "database", 0, NULL, 0); mysql_query(conn, "SELECT * FROM users"); result = mysql_store_result(conn); while (row = mysql_fetch_row(result)) { int id = atoi(row[0]); // assume first column is the ID // update the record here mysql_queryf(conn, "UPDATE users SET name='%s' WHERE id=%d", "John Doe", id); } mysql_free_result(result); mysql_close(conn);In this example, we're using the MySQL database library to fetch records from the "users" table and updating the name field for each record. We first fetch records using the `mysql_fetch_row` function and then update the records using a `mysql_queryf` function. Package/Library: The package/library depends on the specific database management system (DBMS) being used. For example, the SQLite library can be used to manage SQLite databases, while the MySQL library can be used to manage MySQL databases. Other examples of DBMS and their respective C++ libraries/packages include Oracle via the OCI library, PostgreSQL via the libpqxx library, and Microsoft SQL Server via the ODBC library.