Question

我创建了三个表

E:\Soft\lua\5.1\lua.exe: error loading module 'luamidi' from file 'E:\Code\Lua\FakeMagic\testingarea\test\libs\luamidi.dll':
        E:\Code\Lua\FakeMagic\testingarea\test\libs\luamidi.dll:1: '=' expected near 'Р'
stack traceback:
        [C]: ?
        [C]: in function 'require'
        E:\Code\Lua\FakeMagic\testingarea\test\midi.lua:2: in main chunk
        [C]: ?

我正在寻找的答案是：

CREATE TABLE guest(

name varchar(100),
ranking int,
PRIMARY KEY (name)
);

CREATE TABLE room(

 roomname varchar(100),
 wallcolor varchar(100),
 rating int,
 PRIMARY KEY(roomnane)
 );

 CREATE TABLE reservation(

 name varchar(100),
 roomname varchar(100),
 day varchar(100),
 moveinday int,
 moveoutday int,
 PRIMARY KEY(roomname, day, start, finish),
  FOREIGN KEY(roomname) REFERENCES room(roomname),
  FOREIGN KEY(name) REFERENCES guest(name)
 );

我正在尝试制定2个查询

查找在同一天预订同一房间的冲突预订，以覆盖入住和出入时间。即我正在尝试输出roomname，day，name1，start1，finish1，name2，start2，finish2。

我试过了

{LakeView, Monday, John, 10, 14, Reggie, 9, 11}

我不知道如何做where子句并获得正确的输入。任何帮助表示赞赏。

将所有“皇后”房间更改为“King”和“King”房间为“Red”，而不指定所涉及的船只。我不确定如何使用update语句执行此任务。再次感谢任何帮助。

编辑：

这将被插入预订

 select rr.roomname, rr.day, rr.name, rr.start, rr.finish, rr.name, rr.start, rr.finish  
 from room r, guest g, reservation rr
 join reservation r1 on room.roomname = r1.roomname 
 join reservation r2 on room.roomname = r2.roomname

Answer 1

你可以试试这个：

SELECT r1.roomname, r1.day, r1.name, r1.moveinday, r1.moveoutday, r2.name, r2.moveinday, r2.moveoutday
FROM reservation r1
INNER JOIN reservation r2
WHERE r1.roomname = r2.roomname AND
      r1.day = r2.day AND
      (
         r1.moveinday between r2.moveinday and r2.moveoutday OR
         r1.moveoutday between r2.moveinday and r2.moveoutday
      ) AND r1.name <> r2.name

如何使用多个连接语句并更新？

1 个答案: