c++怎么连接和操作PostgreSQL数据库_C++数据库操作与PostgreSQL连接实践

#include <iostream>
#include <pqxx/pqxx>
<p>int main() {
try {
pqxx::connection conn("host=localhost port=5432 dbname=testdb user=postgres password=yourpassword");
if (conn.is_open()) {
std::cout << "成功连接到数据库: " << conn.dbname() << std::endl;
} else {
std::cout << "无法连接数据库" << std::endl;
return 1;
}</p><pre class='brush:php;toolbar:false;'>    conn.close();
} catch (const std::exception &e) {
    std::cerr << "连接异常: " << e.what() << std::endl;
    return 1;
}
return 0;

try {
    pqxx::connection conn("host=localhost port=5432 dbname=testdb user=postgres password=yourpass");
    pqxx::work txn(conn);
<pre class='brush:php;toolbar:false;'>// 插入数据
txn.exec("INSERT INTO users (name, email) VALUES ('Alice', 'alice@example.com')");

// 查询数据
pqxx::result res = txn.exec("SELECT id, name, email FROM users");
for (const auto &row : res) {
    std::cout << "ID: " << row[0].as<int>()
              << ", 名称: " << row[1].as<std::string>()
              << ", 邮箱: " << row[2].as<std::string>() << std::endl;
}

// 更新数据
txn.exec("UPDATE users SET email='newemail@example.com' WHERE name='Alice'");

// 删除数据
txn.exec("DELETE FROM users WHERE name='Alice'");

txn.commit(); // 提交事务

pqxx::work txn(conn);
txn.prepared("insert_user")("text", "text").exec_params("Bob", "bob@example.com");
// 需提前定义预处理语句，或使用动态方式

auto res = txn.exec_params(
    "SELECT * FROM users WHERE age > $1 AND city = $2",
    18, "Beijing"
);