如何编写包含左联接的创建表语句？

Question

I can get a left join with the following mysql statement: Table fields defination:

 show columns from back;
+-------------------------+------------+------+-----+---------+-------+
| Field                   | Type       | Null | Key | Default | Extra |
+-------------------------+------------+------+-----+---------+-------+
| code                    | text       | YES  |     | NULL    |       |
| report_date             | varchar(4) | YES  |     | NULL    |       |
| total_operating_revenue | double     | YES  |     | NULL    |       |
+-------------------------+------------+------+-----+---------+-------+
3 rows in set (0.01 sec)

I have uploaded the table into dropbox

back table download for test mysql statement

My query.

select * from ((
    select *  from  back   
    ) a 
left join(    
    select * from  back  
    ) b on  a.report_date  = b.report_date + 1 
            and  a.code = b.code);

Now i want to rewrite it as a create table statement:

create table result as(( 
    select *  from  back   
    ) a 
left join(    
    select * from  back  
    ) b on  a.report_date  = b.report_date + 1 
            and  a.code = b.code);

I encounter issue:

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '( 
    select *  from  back   
    ) a 
left join(    
    select * from  back  ' at line 1

How to write the create table statement which contains a left join?
@Barmar,both method encounter same error:ERROR 1060 (42S21): Duplicate column name 'code'

MariaDB [finance]> create table result as( 
    -> select * from ((
    ->     select *  from  back   
    ->     ) a 
    -> left join(    
    ->     select * from  back  
    ->     ) b on  a.report_date  = b.report_date + 1 
    ->             and  a.code = b.code));

ERROR 1060 (42S21): Duplicate column name 'code'

The second way:

MariaDB [finance]> CREATE TABLE result AS
    -> SELECT *
    -> FROM back AS a
    -> LEFT JOIN back AS b ON a.report_date = b.report_date + 1 AND a.code = b.code;
ERROR 1060 (42S21): Duplicate column name 'code'

My latest try:

create table result as 
select a.code,a.report_date,a.total_operating_revenue,b.code,b.report_date,b.total_operating_revenue from (
    select a.code,a.report_date,a.total_operating_revenue  from  back   
    ) a 
left join(    
    select b.code,b.report_date,b.total_operating_revenue from  back  
    ) b on  a.report_date  = b.report_date + 1 
            and  a.code = b.code;

Unknown column error:

ERROR 1054 (42S22): Unknown column 'a.code' in 'field list'

Answer 1

Just put create table result before the original query.

create table result as
select * from ((
    select *  from  back   
    ) a 
left join(    
    select * from  back  
    ) b on  a.report_date  = b.report_date + 1 
            and  a.code = b.code);

or without all the subqueries:

CREATE TABLE result AS
SELECT *
FROM back AS a
LEFT JOIN back AS b ON a.report_date = b.report_date + 1 AND a.code = b.code

However, using a self-join with SELECT * will try to create duplicate column names in the new table, which I think will cause another error. You should select specific columns, and if you need the same column from both a and b you must give them different aliases for the new table columns.

Answer 2

CREATE TABLE result AS
select * from ((
    select code as a_code ,report_date as a_report_date,total_operating_revenue as a_revenue from  back   
    ) a 
left join(    
    select code as b_code ,report_date as b_report_date,total_operating_revenue as b_revenue  from  back 
    ) b on  a_report_date  = b_report_date + 1 
            and  a_code = b_code);

Answer 3

edit

You could use this query to create a table with a left join and your condition

create table result as
select a.* from back a
left join back b on (a.report_date = b.report_date + 1) and a.code = b.code;