Task: Parameterized SQL statement
C: #include <stdio.h>
#include <stdlib.h>
#include <sqlite3.h>

static const char* db_file = ":memory:"; 

void check_error(int result_code, sqlite3 *db);
int select_callback(void* data, int column_count, char** columns, char** column_names);

int main(void) {
    sqlite3 *db;
    int result_code;
    char *sql;
    char *insert_statements[4];
    sqlite3_stmt *compiled_statement;
    int i;
    
    
    result_code = sqlite3_open(db_file, &db);
    check_error(result_code, db);    
    
    
    sql = "create table players("
          "id integer primary key asc, "
          "name text, "
          "score real, "
          "active integer, " 
          "jerseyNum integer);";
    result_code = sqlite3_exec(db, sql, NULL, NULL, NULL);
    check_error(result_code, db);    
        
    
    insert_statements[0] = "insert into players (name, score, active, jerseyNum) "
                                        "values ('Roethlisberger, Ben', 94.1, 1, 7);";
    insert_statements[1] = "insert into players (name, score, active, jerseyNum) "
                                        "values ('Smith, Alex', 85.3, 1, 11);";
    insert_statements[2] = "insert into players (name, score, active, jerseyNum) "
                                        "values ('Manning, Payton', 96.5, 0, 18);";
    insert_statements[3] = "insert into players (name, score, active, jerseyNum) "
                                        "values ('Doe, John', 15, 0, 99);";
    
    for (i=0; i<4; i++) {
        result_code = sqlite3_exec(db, insert_statements[i], NULL, NULL, NULL);        
        check_error(result_code, db);    
    }
        
    
    printf("Before update:\n");
    sql = "select * from players;";
    result_code = sqlite3_exec(db, sql, select_callback, NULL, NULL);
    check_error(result_code, db);    
    
    
    sql = "update players set name=?, score=?, active=? where jerseyNum=?;";
    result_code = sqlite3_prepare_v2(db, sql, -1, &compiled_statement, NULL);
    check_error(result_code, db);    
    
    
    result_code = sqlite3_bind_text(compiled_statement, 1, "Smith, Steve", -1, NULL);
    check_error(result_code, db);    
    result_code = sqlite3_bind_double(compiled_statement, 2, 42);
    check_error(result_code, db);    
    result_code = sqlite3_bind_int(compiled_statement, 3, 1);
    check_error(result_code, db);    
    result_code = sqlite3_bind_int(compiled_statement, 4, 99);
    check_error(result_code, db);    
    
    
    result_code = sqlite3_step(compiled_statement);
    if (result_code != SQLITE_DONE) {
        printf("Error #%d: %s\n", result_code, sqlite3_errmsg(db));
        sqlite3_close(db);
        return result_code;
    }
    
    
    result_code = sqlite3_finalize(compiled_statement);
    check_error(result_code, db);        

    
    printf("After update:\n");
    sql = "select * from players;";
    result_code = sqlite3_exec(db, sql, select_callback, NULL, NULL);
    check_error(result_code, db);
    
    
    sqlite3_close(db);        
        
    return EXIT_SUCCESS;
}


void check_error(int result_code, sqlite3 *db) {
    if (result_code != SQLITE_OK) {
        printf("Error #%d: %s\n", result_code, sqlite3_errmsg(db));
        sqlite3_close(db);
        exit(result_code);
    }
}


int select_callback(void* data, int column_count, char** columns, char** column_names) {
    int i;
    
    for (i=0; i<column_count; i++) {
        printf(columns[i]);
        if (i < column_count-1) printf(" | ");
    }
    printf("\n");
}

C++: #include <QtSql>
#include <iostream>




int main(int argc, char *argv[]) {
    if (argc != 4) {
        std::cerr << "Usage: " << argv[0] << " data-source user password\n";
        return 1;
    }
    QSqlDatabase db = QSqlDatabase::addDatabase("QODBC");
    db.setDatabaseName(argv[1]);
    if (!db.open(argv[2], argv[3])) {
        auto error = db.lastError();
        std::cerr << "Cannot connect to data source: " << error.text().toStdString() << '\n';
    } else {
        std::cout << "Connected to data source.\n";
        QSqlQuery query(db);
        query.prepare("UPDATE players SET name = ?, score = ?, active = ? WHERE jerseyNum = ?");
        query.bindValue(0, "Smith, Steve");
        query.bindValue(1, 42);
        query.bindValue(2, true);
        query.bindValue(3, 99);
        if (!query.exec()) {
            auto error = db.lastError();
            std::cerr << "Cannot update database: " << error.text().toStdString() << '\n';
        } else {
            std::cout << "Update succeeded.\n";
        }
    }
    return 0;
}