在每个影院查询中显示所有电影
我正在学习SQL，但我在运行查询时遇到问题。我已经发布了当前查询的屏幕截图，我得到了我想要的所有电影结果以及我想要的结果。它没有显示总共有0个放映的电影。如何收录没有放映的电影？我已经包含了创建表和外键的所有查询。
-- --------------------------------------------------------------------------------
-- Options
-- --------------------------------------------------------------------------------
USE dbSQL1; -- Get out of the master database
SET NOCOUNT ON; -- Report only errors
-- --------------------------------------------------------------------------------
-- Drop Tables
-- --------------------------------------------------------------------------------
DROP TABLE TTicketPrices
DROP TABLE TTicketSales
DROP TABLE TShowings
DROP TABLE TTheaters
DROP TABLE TMovies
DROP TABLE TTicketTypes
DROP TABLE TScreenTypes
-- --------------------------------------------------------------------------------
-- Step #1.1: Create Tables
-- --------------------------------------------------------------------------------
CREATE TABLE TTheaters
(
intTheaterID INTEGER NOT NULL
,strTheater VARCHAR(50) NOT NULL
,strTheaterAddress VARCHAR(50) NOT NULL
,strTheaterCity VARCHAR(50) NOT NULL
,strTheaterState VARCHAR(50) NOT NULL
,CONSTRAINT TTheaters_PK PRIMARY KEY ( intTheaterID )
)
CREATE TABLE TScreenTypes
(
intScreenTypeID INTEGER NOT NULL
,strScreenType VARCHAR(50) NOT NULL
,CONSTRAINT TScreenTypes_PK PRIMARY KEY ( intScreenTypeID )
)
CREATE TABLE TMovies
(
intMovieID INTEGER NOT NULL
,strMovieName VARCHAR(50) NOT NULL
,strDescription VARCHAR(2000) NOT NULL
,intRunningTime INTEGER NOT NULL
,CONSTRAINT TMovies_PK PRIMARY KEY ( intMovieID )
)
CREATE TABLE TShowings
(
intShowingID INTEGER NOT NULL
,intTheaterID INTEGER NOT NULL
,intScreenTypeID INTEGER NOT NULL
,intMovieID INTEGER NOT NULL
,dteShowDate DATE NOT NULL
,tmeShowTime TIME NOT NULL
,CONSTRAINT TMovieShowings_PK PRIMARY KEY ( intShowingID )
)
CREATE TABLE TTicketPrices
(
intTheaterID INTEGER NOT NULL
,intScreenTypeID INTEGER NOT NULL
,intTicketTypeID INTEGER NOT NULL
,monTicketPrice MONEY NOT NULL
,CONSTRAINT TTicketPrices_PK PRIMARY KEY ( intTheaterID, intScreenTypeID, intTicketTypeID )
)
CREATE TABLE TTicketTypes
(
intTicketTypeID INTEGER NOT NULL
,strTicketType VARCHAR(50) NOT NULL --- Adult, Student, Child
,CONSTRAINT TTicketTypes_PK PRIMARY KEY ( intTicketTypeID )
)
CREATE TABLE TTicketSales
(
intTicketSaleID INTEGER NOT NULL
,intShowingID INTEGER NOT NULL
,intTicketTypeID INTEGER NOT NULL
,monTicketPrice MONEY NOT NULL
,CONSTRAINT TTicketSales_PK PRIMARY KEY ( intTicketSaleID )
)
-- ------------------------------------------------------------------------- -------
-- Step #1.2: Identify and Create Foreign Keys
-- ------------------------------------------------------------------------- -------
--
-- # Child Parent Column(s)
-- - ----- ------ ---- -----
-- 1 TShowings TTheaters intTheaterID
-- 2 TShowings TScreenTypess intScreenTypeID
-- 3 TShowings TMovies intMovieID
-- 4 TTicketPrices TTheaters intTheaterID
-- 5 TTicketPrices TScreenTypes intScreenTypeID
-- 6 TTicketPrices TTicketTypes intTicketTypeID
-- 7 TTicketSales TShowings intShowingID
-- 8 TTicketSales TTicketTypes intTicketTypeID
-- 1
ALTER TABLE TShowings ADD CONSTRAINT TShowings_TTheaters_FK
FOREIGN KEY ( intTheaterID ) REFERENCES TTheaters ( intTheaterID )
-- 2
ALTER TABLE TShowings ADD CONSTRAINT TShowings_TScreenTypes_FK
FOREIGN KEY ( intScreenTypeID ) REFERENCES TScreenTypes ( intScreenTypeID )
-- 3
ALTER TABLE TShowings ADD CONSTRAINT TShowings_TMovies_FK
FOREIGN KEY ( intMovieID ) REFERENCES TMovies ( intMovieID )
-- 4
ALTER TABLE TTicketPrices ADD CONSTRAINT TTicketPrices_TTheaters_FK
FOREIGN KEY ( intTheaterID ) REFERENCES TTheaters ( intTheaterID )
-- 5
ALTER TABLE TTicketPrices ADD CONSTRAINT TTicketPrices_TScreenTypes_FK
FOREIGN KEY ( intScreenTypeID ) REFERENCES TScreenTypes ( intScreenTypeID )
-- 6
ALTER TABLE TTicketPrices ADD CONSTRAINT TTicketPrices_TTicketTypes_FK
FOREIGN KEY ( intTicketTypeID ) REFERENCES TTicketTypes ( intTicketTypeID )
-- 7
ALTER TABLE TTicketSales ADD CONSTRAINT TTicketSales_TShowings_FK
FOREIGN KEY ( intShowingID ) REFERENCES TShowings ( intShowingID )
-- 8
ALTER TABLE TTicketSales ADD CONSTRAINT TTicketSale_TTicketTypes_FK
FOREIGN KEY ( intTicketTypeID ) REFERENCES TTicketTypes ( intTicketTypeID )
-- ------------------------------------------------------------------------ --------
-- Step #1.3: Add data
-- ------------------------------------------------------------------------ --------
INSERT INTO TTicketTypes ( intTicketTypeID, strTicketType )
VALUES ( 1, 'Adult' )
,( 2, 'Student')
,( 3, 'Child' )
,( 4, 'Senior') -- No sales for this ticket type.
INSERT INTO TScreenTypes ( intScreenTypeID, strScreenType )
VALUES ( 1, 'Standard' )
,( 2, 'Imax')
,( 3, '3D' )
,( 4, '4D' ) -- No showings for this screen type
INSERT INTO TTheaters ( intTheaterID, strTheater, strTheaterAddress, strTheaterCity, strTheaterState )
VALUES ( 1, 'Old Time Theater', '100 Main Street', 'Covington', 'KY' )
,( 2, 'Super 8 Theater', '8 Your Street ', 'Your Town', 'OH' )
,( 3, 'Main Street Theater', '203 High Road ', 'New Town', 'OH' )
,( 4, 'Fun Time Theater', '20 New Avenue ', 'My Town', 'IN' ) -- No showings for this theater
INSERT INTO TMovies ( intMovieID, strMovieName, strDescription, intRunningTime )
VALUES ( 1, 'Long Journey Home' , 'Heartfeld movie ... ', 165)
,( 2, 'Antartica', 'Educational movie ....', 205)
,( 3, 'Drama on the High Seas', 'Dramatic movie ....', 175)
,( 4, 'Aliens vs. Zombies', 'Scary movie about.....', 105)
,( 5, 'All About Penguins', 'Educational movie.....', 135) -- No showings for this movie
INSERT INTO TShowings ( intShowingID, intTheaterID, intMovieID, intScreenTypeID, dteShowDate, tmeShowTime )
VALUES
( 1, 1, 1, 1, '07/1/2015', '12:30')
,( 2, 1, 1, 1, '07/1/2015', '17:15')
,( 3, 1, 2, 1, '07/1/2015', '22:00')
,( 4, 1, 2, 1, '07/1/2015', '11:00')
,( 5, 1, 2, 1, '07/1/2015', '15:15')
,( 6, 1, 2, 3, '07/1/2015', '20:50')
,( 7, 1, 3, 1, '07/1/2015', '11:15')
,( 8, 1, 3, 1, '07/1/2015', '16:15')
,( 9, 1, 3, 1, '07/1/2015', '22:45')
,( 10, 2, 1, 2, '07/2/2015', '11:30')
,( 11, 2, 1, 2, '07/2/2015', '17:15')
,( 12, 2, 1, 2, '07/2/2015', '23:00')
,( 13, 2, 2, 2, '07/2/2015', '11:00')
,( 14, 2, 2, 1, '07/2/2015', '16:15')
,( 15, 2, 2, 3, '07/2/2015', '20:50')
,( 16, 2, 3, 1, '07/2/2015', '12:15')
,( 17, 2, 3, 1, '07/2/2015', '17:15')
,( 18, 2, 3, 1, '07/2/2015', '23:45')
,( 19, 2, 1, 1, '07/1/2015', '12:00')
,( 20, 3, 3, 3, '07/1/2015', '17:45')
,( 21, 3, 3, 1, '07/1/2015', '22:10')
,( 22, 3, 2, 1, '07/1/2015', '12:00')
,( 23, 3, 2, 1, '07/1/2015', '16:15')
,( 24, 3, 2, 1, '07/1/2015', '22:50')
,( 25, 3, 2, 1, '07/1/2015', '11:45')
,( 26, 3, 3, 2, '07/1/2015', '16:25')
,( 27, 3, 3, 1, '07/1/2015', '23:45')
,( 28, 3, 3, 1, '07/1/2015', '12:00')
,( 29, 1, 2, 3, '07/1/2015', '17:45')
,( 30, 1, 4, 1, '07/1/2015', '22:10')
,( 31, 1, 3, 1, '07/1/2015', '12:00')
,( 32, 2, 3, 1, '07/1/2015', '16:15')
,( 33, 2, 4, 1, '07/1/2015', '22:50')
,( 34, 2, 1, 1, '07/1/2015', '11:45')
,( 35, 3, 2, 3, '07/1/2015', '16:25')
,( 36, 3, 3, 1, '07/1/2015', '23:45')
,( 37, 1, 1, 3, '07/3/2015', '22:10')
,( 38, 1, 3, 1, '07/3/2015', '12:00')
,( 39, 2, 3, 1, '07/3/2015', '16:15')
,( 40, 2, 3, 2, '07/3/2015', '22:50')
,( 41, 2, 1, 1, '07/3/2015', '11:45')
,( 42, 3, 2, 3, '07/3/2015', '16:25')
,( 43, 3, 3, 1, '07/3/2015', '23:45')
INSERT INTO TTicketPrices ( intTheaterID, intScreenTypeID, intTIcketTypeID, monTicketPrice )
VALUES ( 1, 1, 1, 11.00) -- Standard Screen, Adult
,( 1, 1, 2, 8.00) -- Standard Screen, Student
,( 1, 1, 3, 6.50) -- Standard Screen, Child
,( 1, 1, 4, 7.50) -- Standard Screen, Senior
,( 1, 2, 1, 12.00) -- Imax Screen, Adult
,( 1, 2, 2, 9.00) -- Imax Screen, Student
,( 1, 2, 3, 7.00) -- Imax Screen, Child
,( 1, 2, 4, 7.25) -- IMax Screen, Senior
,( 1, 3, 1, 15.00) -- 3D, Adult
,( 1, 3, 2, 12.00) -- 3D, Student
,( 1, 3, 3, 10.00) -- 3D, Child
,( 1, 3, 4, 10.50) -- 3D Screen, Senior
-- Theater 2
,( 2, 1, 1, 11.50) -- Standard Screen, Adult
,( 2, 1, 2, 8.50) -- Standard Screen, Student
,( 2, 1, 3, 6.50) -- Standard Screen, Child
,( 2, 2, 1, 12.50) -- Imax Screen, Adult
,( 2, 2, 2, 9.50) -- Imax Screen, Student
,( 2, 2, 3, 7.50) -- Imax Screen, Child
,( 2, 3, 1, 15.50) -- 3D, Adult
,( 2, 3, 2, 12.50) -- 3D, Student
,( 2, 3, 3, 10.50) -- 3D, Child
,( 2, 4, 1, 15.50) -- 4D, Adult
,( 2, 4, 2, 12.50) -- 4D, Student
,( 2, 4, 3, 10.50) -- 4D, Child
-- Theater 3
,( 3, 1, 1, 11.50) -- Standard Screen, Adult
,( 3, 1, 2, 7.50) -- Standard Screen, Student
,( 3, 1, 3, 5.50) -- Standard Screen, Child
,( 3, 2, 1, 11.50) -- Imax Screen, Adult
,( 3, 2, 2, 9.00) -- Imax Screen, Student
,( 3, 2, 3, 7.00) -- Imax Screen, Child
,( 3, 3, 1, 15.00) -- 3D, Adult
,( 3, 3, 2, 13.00) -- 3D, Student
,( 3, 3, 3, 9.50) -- 3D, Child
INSERT INTO TTicketSales ( intTicketSaleID, intShowingID, intTicketTypeID, monTicketPrice )
VALUES ( 1, 1, 1, 11 )
,( 2, 26, 1, 11.5 )
,( 3, 28, 1, 11.5 )
,( 4, 5, 2, 8 )
,( 5, 26, 3, 7 )
,( 6, 12, 1, 12.5 )
,( 7, 13, 2, 9.5 )
,( 8, 7, 1, 11 )
,( 9, 2, 2, 8 )
,( 10, 16, 3, 6.5 )
,( 11, 8, 1, 11 )
,( 12, 22, 2, 7.5 )
,( 13, 19, 3, 6.5 )
,( 14, 17, 3, 6.5 )
,( 15, 9, 1, 11 )
,( 16, 21, 2, 7.5 )
,( 17, 27, 2, 7.5 )
,( 18, 34, 3, 6.5 )
,( 19, 13, 3, 7.5 )
,( 20, 11, 1, 12.5 )
,( 21, 19, 1, 11.5 )
,( 22, 17, 1, 11.5 )
,( 23, 1, 2, 8 )
,( 24, 36, 3, 5.5 )
,( 25, 11, 2, 9.5 )
,( 26, 17, 2, 8.5 )
,( 27, 20, 2, 13 )
,( 28, 21, 1, 11.5 )
,( 29, 22, 3, 5.5 )
,( 30, 21, 3, 5.5 )
,( 31, 9, 3, 6.5 )
,( 32, 7, 2, 8 )
,( 33, 2, 1, 11 )
,( 34, 3, 1, 11 )
,( 35, 14, 1, 11.5 )
,( 36, 30, 1, 15 )
,( 37, 15, 1, 15.5 )
,( 38, 29, 1, 15 )
,( 39, 6, 1, 15 )
,( 40, 27, 1, 11.5 )
,( 41, 36, 1, 11.5 )
,( 42, 6, 2, 12 )
,( 43, 10, 3, 7.5 )
,( 44, 27, 3, 5.5 )
SELECT
TT.intTheaterID
,TT.strTheater
,TM.intMovieID
,TM.strMovieName
,SUM( TM.intMovieID ) AS intTotalMovies
FROM
TTheaters AS TT --A
,TShowings AS TS --B
,TMovies AS TM --C
WHERE
--A to B
TT.intTheaterID = TS.intTheaterID
--B to C
AND TS.intMovieID = TM.intMovieID
GROUP BY
TT.intTheaterID
,TT.strTheater
,TM.intMovieID
,TM.strMovieName
ORDER BY
TT.intTheaterID
1 个答案:
答案 0 :(得分：2)
不要使用旧式连接。有了这个，这是一个解释。
由于您要计算每部电影的放映次数，我们需要COUNT而不是SUM。其次，我们需要在正确的领域做到这一点。总结一个唯一标识符几乎绝不会做任何事情，因为它是一个任意值。相反，因为您想要查看电影的显示次数，COUNT与显示相关的唯一标识符，而不是电影本身。 COUNT(TS.intShowingID) AS totalShowings
最后，由于电影可以有0个放映，我们需要使用TMovies表作为基表来选择，并LEFT JOIN到它，这样我们就不会删除/限制/过滤任何电影。
TMovies AS TM
LEFT JOIN TShowings TS ON TS.intMovieID = TM.intMovieID
LEFT JOIN TTheaters TT on TT.intTheaterID = TS.intTheaterID
现在，把它们放在一起......
SELECT
TT.intTheaterID
,TT.strTheater
,TM.intMovieID
,TM.strMovieName
,COUNT(TS.intShowingID) AS totalShowings
FROM
TMovies AS TM
LEFT JOIN TShowings TS ON TS.intMovieID = TM.intMovieID
LEFT JOIN TTheaters TT on TT.intTheaterID = TS.intTheaterID
GROUP BY
TM.intMovieID
,TT.intTheaterID
,TT.strTheater
,TM.strMovieName
ORDER BY
TT.intTheaterID
您将看到intMoveID 5没有与之关联的任何影院，因为它没有在任何地方显示。
如果您想要显示所有影院（如没有放映的Fun Time Theatre），您可以使用FULL OUTER JOIN。你应该努力学习很多连接选项。这是结构化查询语言的一个非常关键的方面。
相关问题
最新问题
- 我写了这段代码，但我无法理解我的错误
- 我无法从一个代码实例的列表中删除 None 值，但我可以在另一个实例中。为什么它适用于一个细分市场而不适用于另一个细分市场？
- 是否有可能使 loadstring 不可能等于打印？卢阿
- java中的random.expovariate()
- Appscript 通过会议在 Google 日历中发送电子邮件和创建活动
- 为什么我的 Onclick 箭头功能在 React 中不起作用？
- 在此代码中是否有使用“this”的替代方法？
- 在 SQL Server 和 PostgreSQL 上查询，我如何从第一个表获得第二个表的可视化
- 每千个数字得到
- 更新了城市边界 KML 文件的来源？