来自2个不同数据库的2个SQL查询，创建1个表合并列

Question

Suppose that I have two queries from two databases as below.

LIST 1 from [Alphabet] table

• ABCD

  1. A
  2. B
  3. C
  4. D

LIST 2 from [Integers] table

• Numbers

  2. 101
  3. 201
  4. 301
  5. 401

I would like to merge them so that in Excel sheet, I want to see that alphabet table is in columns A and integers table is in column B.

Here my suggestion:

Create Table merged ( Select [ABCD] from [Alphabet] join with [Numbers]  from [Integers])

How can I improve the quality to work?

And should the row numbers be equal in both tables? Say, 27 letters and 27 integers, or would work with 27 letters and integers [1,20]?

Answer 1

This Is My First Answer and i hope it would help ...Back to your question How can I improve the quality to work? You Must use constraints to enforce rules for the data in your tables. You need two columns of the same type, one on each table [Alphabet table] and [Integers table], to JOIN on. Whether they're primary and foreign keys or not doesn't matter.

And should the row numbers be equal in both tables? the answer is No Depending on what joins you will Use ! SQL joins are used to query data from two or more tables, based on a relationship between the corresponding rows in these tables. • INNER JOIN: Returns all corresponding rows from multiple tables. • LEFT OUTER JOIN: Returns all rows from the left table, corresponding rows in the right table & if there are no matches, returns NULL. • RIGHT OUTER JOIN: Returns all rows from the right table, corresponding rows in the left table, & if there are no matches, returns NULL.