Question

谁能帮我解答一下下面的数据库问题啊？？？？？？？？？？？？？

SELECT A.URN_CONT,B.URN_ACCT,A.EMAIL,B.COMPANY
FROM Contacts A
INNER JOIN Accounts B
CONTACTS
URN_CONT URN_ACCT EMAIL
0123 0001 jonesa@somecompany.com
0457 0002 Changt@anothercompany.com
0879 0004 kellerJ@Lastcompany.com
ACCOUNTS
URN_ACCT COMPANY
0001 Some Company, Inc.
0002 Another Company, Ent.
0003 Last Company, Inc.
Question 1:
Referring to the SQL EXAMPLE #1 and table values above, complete the SQL using the common key needed to join the contacts and Accounts table?

Question 2:
Referring to the SQL EXAMPLE #1 and the table values above, complete the values returned by the SQL query.

URN_CONT URN_ACCT EMAIL COMPANY(3行)

Question 3: The following query generates an error. Can you explain what can be done to the SQL to
correct this error given the data types used for the table queried?
SELECT * FROM cont_ctry WHERE country=US
TABLE: CONT_CTRY
URN_CONT INTEGER NOT NULL,
VENDOR VARCHAR(30) NOT NULL
COUNTRY VARCHAR(3)

Answer 1

SELECT A.URN_CONT,B.URN_ACCT,A.EMAIL,B.COMPANY
FROM Contacts A
INNER JOIN Accounts B

ON A.URN_ACCT = B.URN_ACCT

SELECT * FROM cont_ctry WHERE country='US'

追问

这是第一个的答案么 ？

然后第二题的表是什么样子的呢?

第三题对于报错完全看不明白啊