C++17实现将SQLite3数据导出到CSV文件

使用C++17实现将SQLite3数据导出到CSV文件

当数据量达到百万条时，你需要考虑分批次写入来维持性能问题

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

int main() {
    sqlite3* db;
    int rc = sqlite3_open("your_database.db", &db);
    if (rc) {
        std::cerr << "Error opening database: " << sqlite3_errmsg(db) << std::endl;
        return 1;
    }

    std::ofstream outputFile("output_file.csv");
    if (!outputFile.is_open()) {
        std::cerr << "Failed to open output file." << std::endl;
        return 1;
    }

    const char* sql = "SELECT * FROM your_table;";
    sqlite3_stmt* stmt;
    rc = sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr);
    if (rc != SQLITE_OK) {
        std::cerr << "Error preparing statement: " << sqlite3_errmsg(db) << std::endl;
        return 1;
    }

    while ((rc = sqlite3_step(stmt)) == SQLITE_ROW) {
        for (int i = 0; i < sqlite3_column_count(stmt); ++i) {
            outputFile << sqlite3_column_text(stmt, i);
            if (i < sqlite3_column_count(stmt) - 1) {
                outputFile << ",";
            }
        }
        outputFile << "\n";
    }

    sqlite3_finalize(stmt);
    sqlite3_close(db);
    outputFile.close();

    return 0;
}