Question

我正在尝试从两个选择的句子中获得内部联接，但这是行不通的，我在做什么错了？

我不能使用内部表，因为内部联接不允许它。

#include <stdio.h>
#include <math.h>
#include <SDL2\SDL2_gfxPrimitives.h>
#include <SDL2\SDL.h>

const int SCREEN_WIDH = 640;
const int SCREEN_HEIGHT = 480;

int main(int argc, char *argv[]) {
    if (SDL_Init(SDL_INIT_EVERYTHING) < 0) {
        SDL_Log("Nem indithato az SDL: %s", SDL_GetError());
        exit(1);
    }
    SDL_Window *window = SDL_CreateWindow("SDL peldaprogram", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 440, 360, 0);
    if (window == NULL) {
        SDL_Log("Nem hozhato letre az ablak: %s", SDL_GetError());
        exit(1);
    }
    SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_SOFTWARE);
    if (renderer == NULL) {
        SDL_Log("Nem hozhato letre a megjelenito: %s", SDL_GetError());
        exit(1);
    }
    SDL_RenderClear(renderer);

    int x, y, r;

    //circleRGBA(renderer, x, y, r, 255, 0, 0, 255);
    //circleRGBA(renderer, x + r, y, r, 0, 255, 0, 255);
    //circleRGBA(renderer, x + r * cos(3.1415 / 3), y - r * sin(3.1415 / 3), r, 0, 0, 255, 255);

    SDL_RenderPresent(renderer);

    SDL_Event ev;
    while (SDL_WaitEvent(&ev) && ev.type != SDL_QUIT) {
    }

    SDL_Quit();
    return 0;
}

我希望表格CMakeFiles\pontok.dir/objects.a(main.c.obj): In function `SDL_main': C:/Prog/pontok/main.c:28: undefined reference to `circleRGBA' C:/Prog/pontok/main.c:29: undefined reference to `circleRGBA' C:/Prog/pontok/main.c:30: undefined reference to `circleRGBA' collect2.exe: error: ld returned 1 exit status mingw32-make.exe[3]: *** [CMakeFiles\pontok.dir\build.make:88: pontok.exe] Error 1 mingw32-make.exe[2]: *** [CMakeFiles\Makefile2:75: CMakeFiles/pontok.dir/all] Error 2 mingw32-make.exe[1]: *** [CMakeFiles\Makefile2:82: CMakeFiles/pontok.dir/rule] Error 2 mingw32-make.exe: *** [Makefile:117: pontok] Error 2到城市和从城市到城市的频率更高。

Answer 1

首先，我不认为您正在执行正确的SELECT以获得所需的内容。我从技术角度回答这个问题。您可以使用WITH。

WITH +spf1 AS (
  SELECT spfli~cityto AS cityto, COUNT(*) AS count FROM spfli GROUP BY spfli~cityto ) ,

     +spf2 AS (
  SELECT spfli~cityfrom AS cityfrom , COUNT(*) AS count FROM spfli GROUP BY spfli~cityfrom ) ,

     +spf3 AS ( 
  SELECT s1~cityto, s2~cityfrom FROM +spf1 AS s1 INNER JOIN +spf2 AS s2
      ON s1~cityto = s2~cityfrom )

SELECT * FROM +spf3 INTO TABLE @DATA(lt_result).

如何修复“ ABAP INNER JOIN”

1 个答案: