如何在JOIN中返回主表的内容？

Question

I have table1 and table2 my goal is execute a query that take all data available (matching the code), this is my query actually:

SELECT * FROM table1
         INNER JOIN table2
         ON table1.code = table2.code

All working good, but if for example in the table2 a specific code isn't exists the data of the table1 aren't returned. An example:

TABLE1

|CODE|Info|
|R789|Home|
|R788|Away|

TABLE2

|CODE|DESCRIPTION|
|R789| Test

will return only the content of R789 , but I want that also the content of R788 must be returned, of course only the field of table1 'cause in table2 the record doesn't exists. How can I do that?

Answer 1

Use a LEFT JOIN , which will return content from both tables if the "CODE" exists in both, and items from Table1 with NULL s for items from Table2 if the code doesn't exist there.

Lots of documentation out there for this. Here's one example and another one .

Answer 2

If you want to get all the data from both tables but matching if corresponds, you should use a full outer join:

select a.*,
       b.*
from   table1 a
full   outer join
       table2 b
on     a.code=b.code

It will returns something like this:

|CODE|Info|CODE|DESCRIPTION|
|R789|Home|R789|Test|
|R788|Away|null|null|

Regards