使用vs2022 连接sql server数据库的完整c语言示例代码

在Visual Studio 2022中连接SQL Server数据库，你需要使用ODBC（Open Database Connectivity）库或者ADO.NET（ActiveX Data Objects for .NET）。这里是一个使用ADO.NET的C#示例，如果你想要C语言的话，由于VS2022主要支持C++，可以参考以下C++代码，它使用了SQL Server的硫酸驱动程序(sqljdbc_auth.lib)：

#include <windows.h>
#include <iostream>
#include <sql.h>
#include <sqlext.h>

using namespace std;

int main() {
    SQLHENV env; // 数据库环境
    SQLHDBC dbc; // 数据库连接
    SQLRETURN ret;
    
    // 初始化环境
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
    if (ret != SQL_SUCCESS) {
        cerr << "Error initializing environment: " << SQLGetErrorString(ret, NULL) << endl;
        return 1;
    }
    
    ret = SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (SQLPOINTER)SQL_OV_ODBC3, 0);
    if (ret != SQL_SUCCESS) {
        cerr << "Error setting ODBC version: " << SQLGetErrorString(ret, NULL) << endl;
        SQLFreeHandle(SQL_HANDLE_ENV, env);
        return 1;
    }

    // 创建数据库连接
    ret = SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);
    if (ret != SQL_SUCCESS) {
        cerr << "Error creating database connection: " << SQLGetErrorString(ret, NULL) << endl;
        SQLFreeHandle(SQL_HANDLE_ENV, env);
        return 1;
    }

    // 配置连接字符串
    char* connStr = "Driver={SQL Server};Server=your_server_name;Database=your_database;uid=your_username;pwd=your_password;";
    SQLCHAR *connStrChars = (SQLCHAR*) connStr;

    // 连接到数据库
    ret = SQLConnect(dbc, connStrChars, SQL_NTS, NULL, 0, NULL);
    if (ret != SQL_SUCCESS) {
        cerr << "Error connecting to the database: " << SQLGetErrorString(ret, NULL) << endl;
        SQLDisconnect(dbc);
        SQLFreeHandle(SQL_HANDLE_DBC, dbc);
        SQLFreeHandle(SQL_HANDLE_ENV, env);
        return 1;
    }

    cout << "Connected to SQL Server successfully!" << endl;

    // 示例：执行查询并关闭连接
    SQLHSTMT stmt;
    ret = SQLAllocHandle(SQL_HANDLE_STMT, dbc, &stmt);
    if (ret == SQL_SUCCESS) {
        SQLCHAR sql[] = "SELECT * FROM your_table";
        ret = SQLExecDirect(stmt, sql, SQL_NTS);
        if (ret == SQL_SUCCESS) {
            // 打印结果
            // ...处理查询结果...
            SQLFreeHandle(SQL_HANDLE_STMT, stmt);
        } else {
            cerr << "Error executing query: " << SQLGetErrorString(ret, NULL) << endl;
        }
    }

    // 关闭连接
    SQLDisconnect(dbc);
    SQLFreeHandle(SQL_HANDLE_STMT, stmt);
    SQLFreeHandle(SQL_HANDLE_DBC, dbc);

    SQLFreeHandle(SQL_HANDLE_ENV, env);
    cout << "Connection closed." << endl;

    return 0;
}