c连接mysql obc

#include <stdio.h>
#include <stdlib.h>
#include <sql.h>
#include <sqlext.h>

void check_return(int ret, SQLSMALLINT handle_type, SQLHANDLE handle, const char *msg) {
    if (ret != SQL_SUCCESS) {
        fprintf(stderr, "%s\n", msg);
        exit(1);
    }
}

int main() {
    SQLHENV env;
    SQLHDBC dbc;
    SQLRETURN ret;

    // Allocate environment handle
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &env);
    check_return(ret, SQL_HANDLE_ENV, env, "Failed to allocate environment handle");

    // Set the ODBC version environment attribute
    ret = SQLSetEnvAttr(env, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);
    check_return(ret, SQL_HANDLE_ENV, env, "Failed to set ODBC version");

    // Allocate connection handle
    ret = SQLAllocHandle(SQL_HANDLE_DBC, env, &dbc);
    check_return(ret, SQL_HANDLE_DBC, dbc, "Failed to allocate connection handle");

    // Connect to the database
    ret = SQLConnect(dbc, (SQLCHAR*)"your_database", SQL_NTS, (SQLCHAR*)"your_username", SQL_NTS, (SQLCHAR*)"your_password", SQL_NTS);
    check_return(ret, SQL_HANDLE_DBC, dbc, "Failed to connect to the database");

    printf("Connected to the database successfully!\n");

    // Free handles
    SQLDisconnect(dbc);
    SQLFreeHandle(SQL_HANDLE_DBC, dbc);
    SQLFreeHandle(SQL_HANDLE_ENV, env);

    return 0;
}