MySQL return a blank row every other row from a select?

I'm wondering if there is a way for a select statement to return an empty row (or a row with all empty values for each column) every开发者_StackOverflow中文版 other row, so that I can avoid doing this after exporting the results from MySQL.

I've been unable to do so any way I could think of, and google leads me no where.

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Lets say I have a table user with 3 columns: user_id, user_name and password. Here is a method using a LEFT JOIN to select a row of null values for every columns of a table without specifying the columns individually in the SELECT:

SELECT u.*
FROM (SELECT null) a
LEFT JOIN `user` u
ON false;

This query will return:

+---------+-----------+----------+
| user_id | user_name | password |
+---------+-----------+----------+
|    NULL |      NULL |     NULL |
+---------+-----------+----------+

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I'm not 100% sure I got what you want. Are you looking for something like SELECT * FROM table1 LIMIT 0 ?

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Sometimes this is really necessary, such as when using a database for applications.

Use just:

select 0 limit 0;

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(note: I cannot leave comments yet, so I'm posting this here) Maybe this will help you get started?

You would have to find a way to loop through this:

SELECT col1, col2, col3 FROM table LIMIT 1 UNION SELECT "", "", "";

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set @i := 0;
set @j := 1;

select c1
from (
    select c1, @i := @i + 2 as o
    from my_table
    union
    select '' as c1, @j := @j + 2 as o
    from my_table
) ss
order by o
;

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SELECT col1, col2, col3
FROM (
      SELECT dummy, col1, col2, col3
      FROM (
        SELECT col1 AS dummy, col1, col2, col3
        FROM dumbtask
        ORDER BY col1
       ) t1
       UNION ALL
       (
        SELECT col1 AS dummy, NULL AS col1, NULL AS col2, NULL AS col3
        FROM dumbtask
        ORDER BY dummy
       )
      ORDER BY dummy) t3;

I have to say though ... this is one of the most stupid tasks that I've seen lately.

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Instead of using Select, it is possible just place

values row(null)

or

values row('Or', 'any', 'other'), row('rows','and','columns')