SQL 连接两列并连接两个表

Question

Table person :

| id | f_name | l_name |

Table sales :

| id | amount | date | itemname |

I have a problem joining the two tables which concat f_name and last_name as fullname column, and joining with table sales. Here id is same on both tables.

Output:

| itemname| date |fullname |

What I have tried:

select * 
from
    (select 
         concat(f_name, l_name) as fullname 
     from 
         tblperson) p 
left join
    select itemname, date 
    from table sales s on s.id = p.id

Answer 1

It should actually be

SELECT table_sales.*, concat(table_person.f_name, table_person.l_name) as fullname
FROM table_person
LEFT JOIN table_sales
ON table_person.id = table_sales.id

have not tested this but that is the syntax

Answer 2

you're missing a field like person_id in your sales table (which references the id field in the person table). You can then use a join to properly join the data together.

Answer 3

You are so close. Try this

select p.*,concat(f_name,l_name)as fullname, s.itemname,s.date, s.amount
    from person p left join
    sales  s on s.id=p.id

Here ia good read on sql join. https://www.w3schools.com/sql/sql_join.asp