Using Different Order by with Union

Using different order by with union

This should work:

SELECT * 
FROM (SELECT TOP 10 A.*, 0 AS Ordinal
      FROM A
      ORDER BY [Price]) AS A1

UNION ALL

SELECT * 
FROM (SELECT TOP 3 A.*, 1 AS Ordinal
      FROM A
      ORDER BY [Name]) AS A2

ORDER BY Ordinal

From MSDN:

In a query that uses UNION, EXCEPT, or INTERSECT operators, ORDER BY
is allowed only at the end of the statement. This restriction applies
only to when you specify UNION, EXCEPT and INTERSECT in a top-level
query and not in a subquery.

Edited: to force the order you need to apply an ORDER BY to the outer query. I've added a constant value column to both queries.

Mysql multiple ORDER BY with UNION

Try this

SELECT n.nid, max(na.gid) as mid,fav.field_date_posted_value, UNIX_TIMESTAMP(fav.field_date_posted_value) as pdate, 1 as ob FROM `node` as n
JOIN nodeaccess AS na ON na.nid = n.nid
LEFT JOIN field_data_field_date_posted AS fav ON fav.entity_id = n.nid
WHERE (na.gid IN(10,11) AND (n.status = '1') AND (n.type IN  ('article','blog', 'events', 'media', 'press_releases', 'expert_speak', 'feature', 'case_study', 'news', 'the_igtb_series', 'trend', 'white_paper')) )
GROUP BY n.nid 

UNION ALL

SELECT n.nid, max(na.gid) as mid,fav.field_date_posted_value, UNIX_TIMESTAMP(fav.field_date_posted_value) as pdate, 2 as ob FROM `node` as n
JOIN nodeaccess AS na ON na.nid = n.nid
LEFT JOIN field_data_field_date_posted AS fav ON fav.entity_id = n.nid
WHERE (na.gid IN(2) AND (n.status = '1') AND (n.type IN  ('article','blog', 'events', 'media', 'press_releases', 'expert_speak', 'feature', 'case_study', 'news', 'the_igtb_series', 'trend', 'white_paper')) )
GROUP BY n.nid  

ORDER BY ob ASC, pdate DESC

Fixed the order by date only base or group

Apply ORDER BY on a UNION (Mysql)

SELECT *
FROM (
(SELECT * FROM user_relation WHERE from_user_id = 1)
UNION
(SELECT * FROM user_relation WHERE to_user_id = 1)
) AS i
ORDER BY trust_degree

You have to assign an alias to your select. But in this case a UNION is not necessary and could be replaced by a simple OR, as @Karoly Horvath points out in his comment. The resulting query would look like this:

SELECT 
 * 
FROM user_relation 
WHERE from_user_id = 1 OR to_user_id = 1 
ORDER BY trust_degree

Using group/order by with union clause in sql query

A union query may only have one order by clause.

If you are satisfied with ordering the whole resultset, you can remove all order by clauses and just keep the very last one, at the end of the query. It applies to the entire dataset that union generates.

Note that your UNIONs are equivalent to UNION ALLs - because the client name is different in each member - and should be phrased as such.

If, on the other hand, you want to order reach sub-result, then this is different. Basically you need a flag in each member, that can then be used to identify each group. The client name might be a good pick, so:

order by client_name, client_id

How to use order by with union all in sql?

SELECT  * 
FROM 
        (
            SELECT * FROM TABLE_A 
            UNION ALL 
            SELECT * FROM TABLE_B
        ) dum
-- ORDER BY .....

but if you want to have all records from Table_A on the top of the result list, the you can add user define value which you can use for ordering,

SELECT  * 
FROM 
        (
            SELECT *, 1 sortby FROM TABLE_A 
            UNION ALL 
            SELECT *, 2 sortby FROM TABLE_B
        ) dum
ORDER   BY sortby 

Using union and order by clause in mysql

You can do this by adding a pseudo-column named rank to each select, that you can sort by first, before sorting by your other criteria, e.g.:

select *
from (
    select 1 as Rank, id, add_date from Table 
    union all
    select 2 as Rank, id, add_date from Table where distance < 5
    union all
    select 3 as Rank, id, add_date from Table where distance between 5 and 15
) a
order by rank, id, add_date desc

How to use ORDER BY inside UNION

Something like this should work in MySQL:

SELECT a.*
  FROM ( 
         SELECT ...  FROM ... ORDER BY ... 
       ) a
 UNION ALL 
SELECT b.*
  FROM ( 
         SELECT ...  FROM ... ORDER BY ... 
       ) b

to return rows in an order we'd like them returned. i.e. MySQL seems to honor the ORDER BY clauses inside the inline views.

But, without an ORDER BY clause on the outermost query, the order that the rows are returned is not guaranteed.

If we need the rows returned in a particular sequence, we can include an ORDER BY on the outermost query. In a lot of use cases, we can just use an ORDER BY on the outermost query to satisfy the results.

But when we have a use case where we need all the rows from the first query returned before all the rows from the second query, one option is to include an extra discriminator column in each of the queries. For example, add ,'a' AS src in the first query, ,'b' AS src to the second query.

Then the outermost query could include ORDER BY src, name, to guarantee the sequence of the results.

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FOLLOWUP

In your original query, the ORDER BY in your queries is discarded by the optimizer; since there is no ORDER BY applied to the outer query, MySQL is free to return the rows in whatever order it wants.

The "trick" in query in my answer (above) is dependent on behavior that may be specific to some versions of MySQL.

Test case:

populate tables

CREATE TABLE foo2 (id INT PRIMARY KEY, role VARCHAR(20)) ENGINE=InnoDB;
CREATE TABLE foo3 (id INT PRIMARY KEY, role VARCHAR(20)) ENGINE=InnoDB;

INSERT INTO foo2 (id, role) VALUES 
  (1,'sam'),(2,'frodo'),(3,'aragorn'),(4,'pippin'),(5,'gandalf');
INSERT INTO foo3 (id, role) VALUES 
  (1,'gimli'),(2,'boromir'),(3,'elron'),(4,'merry'),(5,'legolas');

query

SELECT a.*
  FROM ( SELECT s.id, s.role
           FROM foo2 s
          ORDER BY s.role
       ) a
 UNION ALL
SELECT b.*
  FROM ( SELECT t.id, t.role
           FROM foo3 t
          ORDER BY t.role
       ) b

resultset returned

    id  role     
 ------  ---------
      3  aragorn  
      2  frodo    
      5  gandalf  
      4  pippin   
      1  sam      
      2  boromir  
      3  elron    
      1  gimli    
      5  legolas  
      4  merry    

The rows from foo2 are returned "in order", followed by the rows from foo3, again, "in order".

Note (again) that this behavior is NOT guaranteed. (The behavior we observer is a side effect of how MySQL processes inline views (derived tables). This behavior may be different in versions after 5.5.)

If you need the rows returned in a particular order, then specify an ORDER BY clause for the outermost query. And that ordering will apply to the entire resultset.

As I mentioned earlier, if I needed the rows from the first query first, followed by the second query, I would include a "discriminator" column in each query, and then include the "discriminator" column in the ORDER BY clause. I would also do away with the inline views, and do something like this:

SELECT s.id, s.role, 's' AS src
  FROM foo2 s
 UNION ALL
SELECT t.id, t.role, 't' AS src
  FROM foo3 t
 ORDER BY src, role

Create a UNION ALL query when the columns are in different order

Alas, no. UNION ALL goes by position not by names. However, you can generate the columns:

select string_agg(column_name, ', ')
from information_schema.columns
where table_name = ? and
      table_schema = ?;

You can then plug the list into your code.

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