Database Connectivity (SQLite) Gaming Project in C++

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2 months ago

#include <iostream>
#include <sqlite3.h>

using namespace std;

class Database {
public:
    Database(const string& dbName);
    ~Database();
    void createTable();
    void insertData(const string& playerName, int score);
    void displayData();

private:
    sqlite3* db;
    string dbName;

    static int callback(void* NotUsed, int argc, char** argv, char** azColName);
    void executeSQL(const string& sql);
};

Database::Database(const string& dbName) : db(nullptr), dbName(dbName) {
    if (sqlite3_open(dbName.c_str(), &db)) {
        cerr << "Can't open database: " << sqlite3_errmsg(db) << endl;
        exit(1);
    } else {
        cout << "Opened database successfully" << endl;
    }
}

Database::~Database() {
    if (db) {
        sqlite3_close(db);
        cout << "Closed database successfully" << endl;
    }
}

void Database::createTable() {
    string sql = "CREATE TABLE IF NOT EXISTS SCORES("
                 "ID INTEGER PRIMARY KEY AUTOINCREMENT,"
                 "PLAYER_NAME TEXT NOT NULL,"
                 "SCORE INT NOT NULL);";

    executeSQL(sql);
    cout << "Table created successfully" << endl;
}

void Database::insertData(const string& playerName, int score) {
    string sql = "INSERT INTO SCORES (PLAYER_NAME, SCORE) VALUES ('" + playerName + "', " + to_string(score) + ");";
    executeSQL(sql);
    cout << "Data inserted successfully" << endl;
}

void Database::displayData() {
    string sql = "SELECT * FROM SCORES;";
    executeSQL(sql);
}

int Database::callback(void* NotUsed, int argc, char** argv, char** azColName) {
    for (int i = 0; i < argc; i++) {
        cout << azColName[i] << ": " << (argv[i] ? argv[i] : "NULL") << endl;
    }
    cout << endl;
    return 0;
}

void Database::executeSQL(const string& sql) {
    char* errMsg = 0;
    int rc = sqlite3_exec(db, sql.c_str(), callback, 0, &errMsg);
    if (rc != SQLITE_OK) {
        cerr << "SQL error: " << errMsg << endl;
        sqlite3_free(errMsg);
    }
}

int main() {
    Database db("game_scores.db");

    db.createTable();
    db.insertData("Player1", 100);
    db.insertData("Player2", 150);
    db.insertData("Player3", 200);

    cout << "Displaying data:" << endl;
    db.displayData();

    return 0;
}

#include <iostream>

#include <sqlite3.h>

using namespace std;

class Database {

public:

Database(const string& dbName);

~Database();

void createTable();

void insertData(const string& playerName, int score);

void displayData();

private:

sqlite3* db;

string dbName;

static int callback(void* NotUsed, int argc, char** argv, char** azColName);

void executeSQL(const string& sql);

};

Database::Database(const string& dbName) : db(nullptr), dbName(dbName) {

if (sqlite3_open(dbName.c_str(), &db)) {

cerr << "Can't open database: " << sqlite3_errmsg(db) << endl;

exit(1);

} else {

cout << "Opened database successfully" << endl;

}

Database::~Database() {

if (db) {

sqlite3_close(db);

cout << "Closed database successfully" << endl;

}

void Database::createTable() {

string sql = "CREATE TABLE IF NOT EXISTS SCORES("

"ID INTEGER PRIMARY KEY AUTOINCREMENT,"

"PLAYER_NAME TEXT NOT NULL,"

"SCORE INT NOT NULL);";

executeSQL(sql);

cout << "Table created successfully" << endl;

}

void Database::insertData(const string& playerName, int score) {

string sql = "INSERT INTO SCORES (PLAYER_NAME, SCORE) VALUES ('" + playerName + "', " + to_string(score) + ");";

executeSQL(sql);

cout << "Data inserted successfully" << endl;

}

void Database::displayData() {

string sql = "SELECT * FROM SCORES;";

executeSQL(sql);

}

int Database::callback(void* NotUsed, int argc, char** argv, char** azColName) {

for (int i = 0; i < argc; i++) {

cout << azColName[i] << ": " << (argv[i] ? argv[i] : "NULL") << endl;

}

cout << endl;

return 0;

}

void Database::executeSQL(const string& sql) {

char* errMsg = 0;

int rc = sqlite3_exec(db, sql.c_str(), callback, 0, &errMsg);

if (rc != SQLITE_OK) {

cerr << "SQL error: " << errMsg << endl;

sqlite3_free(errMsg);

}

int main() {

Database db("game_scores.db");

db.createTable();

db.insertData("Player1", 100);

db.insertData("Player2", 150);

db.insertData("Player3", 200);

cout << "Displaying data:" << endl;

db.displayData();

return 0;

}

Explanation:

SQLite3 Integration:
- The program uses the SQLite3 library to handle database operations. Make sure to link the SQLite library during compilation (e.g., -lsqlite3
  
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  ).
Database Class:
- The Database class encapsulates all the SQLite-related functionality, including connecting to the database, creating tables, inserting data, and retrieving data.
Constructor & Destructor:
- The constructor opens the SQLite database specified by dbName. If the database does not exist, SQLite creates it.
- The destructor ensures the database connection is closed properly when the Database object is destroyed.
Create Table:
- The createTable method creates a SCORES table if it doesn’t already exist. The table has three columns: ID (an auto-incrementing primary key), PLAYER_NAME (a string), and SCORE (an integer).
Insert Data:
- The insertData method inserts a new player’s name and score into the SCORES table. It constructs an SQL INSERT statement using the provided data and executes it.
Display Data:
- The displayData method retrieves all records from the SCORES table and displays them. It executes a SELECT statement and uses a callback function to handle the results.
Callback Function:
- The static callback function is used by SQLite to process the results of a SELECT
  
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  statement. It prints each column of the result to the console.
Main Function:
- The main function demonstrates how to use the Database class. It creates a database, creates the SCORES table, inserts some sample data, and displays the stored data.

Possible Enhancements:

Parameterized Queries: Use prepared statements to avoid SQL injection and improve performance.
Error Handling: Enhance error handling to manage more complex scenarios.
Dynamic Input: Allow users to input data dynamically instead of hardcoding values.
Extend Functionality: Add features like updating scores, deleting records, or querying specific data.

Explanation:

Possible Enhancements:

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