VC++6.0 Sqlite3调用例子

在VC++ 6.0中调用SQLite 3的示例代码如下：

#include <iostream>
#include <sqlite3.h>
 
int main(int argc, char* argv[])
{
    sqlite3* db;
    char* errMsg = nullptr;
    int rc;
 
    // 打开数据库
    rc = sqlite3_open("example.db", &db);
    if (rc) {
        std::cerr << "无法打开数据库: " << sqlite3_errmsg(db) << std::endl;
        sqlite3_close(db);
        return 1;
    }
 
    // 创建一个表
    const char* createTableSQL = 
        "CREATE TABLE IF NOT EXISTS users ("
        "id INTEGER PRIMARY KEY,"
        "username TEXT,"
        "email TEXT"
        ");";
    rc = sqlite3_exec(db, createTableSQL, nullptr, nullptr, &errMsg);
    if (rc != SQLITE_OK) {
        std::cerr << "SQL错误: " << errMsg << std::endl;
        sqlite3_free(errMsg);
    }
 
    // 插入数据
    const char* insertSQL = "INSERT INTO users (username, email) VALUES ('Alice', 'alice@example.com');";
    rc = sqlite3_exec(db, insertSQL, nullptr, nullptr, &errMsg);
    if (rc != SQLITE_OK) {
        std::cerr << "SQL错误: " << errMsg << std::endl;
        sqlite3_free(errMsg);
    }
 
    // 查询数据
    const char* selectSQL = "SELECT id, username, email FROM users;";
    sqlite3_stmt* stmt;
    rc = sqlite3_prepare_v2(db, selectSQL, -1, &stmt, nullptr);
    if (rc == SQLITE_OK) {
        while (sqlite3_step(stmt) == SQLITE_ROW) {
            int id = sqlite3_column_int(stmt, 0);
            const unsigned char* username = sqlite3_column_text(stmt, 1);
            const unsigned char* email = sqlite3_column_text(stmt, 2);
            std::cout << "ID: " << id << ", Username: " << username << ", Email: " << email << std::endl;
        }
        sqlite3_finalize(stmt);
    } else {
        std::cerr << "SQL错误: " << errMsg << std::endl;
        sqlite3_free(errMsg);
    }
 
    // 关闭数据库
    sqlite3_close(db);
    return 0;
}

这段代码展示了如何在VC++ 6.0中使用SQLite 3的基本操作，包括打开数据库、创建表、插入数据、查询数据和关闭数据库。注意，这里假设SQLite 3的库文件已经被正确配置，并且example.db数据库文件存在于程序可执行文件的相同目录下。