[英]How do I join two tables in SQL to grab the names from one table and show them in a query?
[英]How do I join two tables from a database in SQL?
我目前正在做一个项目,我们必须在 SQL 中加入两个表,然后创建一个页面来显示两个表组合的结果。
这是我到目前为止所拥有的:
SELECT *
FROM
ANIMAL
LEFT OUTER JOIN
FOOD_PORTION
ON
ANIMAL = FOOD_PORTION
然后是第二页,结果应该是:
CREATE TABLE ANIMAL(
AnimalID CHAR(5) PRIMARY KEY,
AnimalName CHAR(50) NOT NULL,
Species CHAR(50) NOT NULL,
Weight INT NOT NULL,
DOB DATE NOT NULL,
ExhibitID CHAR(5) REFERENCES EXHIBIT(ExhibitID)
);
CREATE TABLE FOOD_PORTION(
PortionSize INT NOT NULL,
AnimalID CHAR(5) REFERENCES ANIMAL(AnimalID)
);
SELECT C.Name
FROM ANIMAL AS C
UNION
SELECT S.Name
FROM FOOD_PORTION AS S
这应该给你你所需要的。 使用 tadman 的建议将 char 列更改为 INT。 还将 CHAR 更改为 VARCHAR 列。
我还在每个表的标识列中创建了 ID(因此它们将自动填充)。
CREATE TABLE ANIMAL(
AnimalID INT PRIMARY KEY IDENTITY,
AnimalName VARCHAR(50) NOT NULL,
Species VARCHAR(50) NOT NULL,
Weight INT NOT NULL,
DOB DATE NOT NULL,
ExhibitID CHAR(5) REFERENCES EXHIBIT(ExhibitID)
);
CREATE TABLE FOOD_PORTION(
PortionSize INT IDENTITY,
AnimalID INT REFERENCES ANIMAL(AnimalID)
);
SELECT A.*, FP.*
FROM Animal A
INNER JOIN Food_Portion FP ON A.AnimalID = FP.AnimalID
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