Complicated (for me) Order By issue...

[Jim R]

I want to get the most recent 15 instances of my a_players_review table THEN sort them by grade, then last name.  Ordering the r.id first just gives me a list of rows that I can't do much else with, unless I'm missing how I can code the output. 

Below is what I had.  ORDER BY looked good until I started filling in more rows and seeing kids in grade = 2021 pushing more recent rows off the list.  

Nested ORDER BY seems frowned upon, and I'm not even sure they work.  I kept getting parameters errors.  I really can't make heads or tails of nested SELECTs.  That might be the answer, but I've been unable to take what I've seen and apply it without getting a parameters error.  

 

 

		$query = "SELECT *,p.id,b.playerID,b.id,s.toggle AS stoggle,o.toggle AS otoggle,p.city,p.school,s.city,s.school,r.opp_city,r.opp_school,o.city,o.school,r.city,r.school 
		FROM a_players_reviews r 
		
		LEFT JOIN a_players p 
			ON CONCAT (r.nameFirst,r.nameLast) = CONCAT (p.nameFirst,p.nameLast)
	
		LEFT JOIN a_schools s 
			ON CONCAT(r.city,r.school) = CONCAT(s.city,s.school)
		LEFT JOIN a_schools o	
		 	ON CONCAT(r.opp_city,r.opp_school) = CONCAT(o.city,o.school)
		
		LEFT JOIN a_player_bookmark b
			ON p.id = b.playerID && '". $userID ."' = b.userID
		
		WHERE p.id = b.playerID && '". $userID ."' = b.userID && bookmark>0
		ORDER BY p.grade,p.nameLast,r.id desc
		LIMIT 15
		";

 

Edited April 7, 2020 by Jim R

[Barand]

7 minutes ago, Jim R said:

I want to get the most recent 15 instances of my a_players_review table

You'll stand a better chance of doing that if it is one of the tables in the query.

[Jim R]

It is.  Scroll across.  (Either you didn't see it, or you're commenting on a typo in my explanation.)

 

EDIT:  Added a carriage return for visual assistance. 

Edited April 7, 2020 by Jim R

[Jim R]

Not sure what you were referring to.  

[Barand]

I just didn't see the table - the end of that first line was somewhere in my neighbour's living room. 

[Jim R]

Any thoughts on how to get the results?  

[kicken]

How do you determine the most recent entries from a_players_reviews?  Is there a datetime column to sort by? Do you want just the most recent row for each player, or the most recent 15 even if multiple of them are from the same player?

Sample data and desired output would go a long way to describing what you want.

[Jim R]

14 hours ago, kicken said:

How do you determine the most recent entries from a_players_reviews?  Is there a datetime column to sort by? Do you want just the most recent row for each player, or the most recent 15 even if multiple of them are from the same player?

Sample data and desired output would go a long way to describing what you want.

Just the most recent 15 rows--so a_players_reviews 'r.id'.  I have a timestamp as well, but r.id is the same.  

From there, I want to organize them by grade then last name.  

I did try r.id first in the Order By, but unless I'm missing something, that's not going to allow me to organize them the way I want to.  I tried Group By r.id as well with Order By p.grade,p.nameLast, but same result (which makes sense).  

 

 

[kicken]

You'll want to do a sub-query to get the most recent 15 in order by the ID, then sort the results of that sub query how you want.

SELECT *
FROM (
    SELECT 
        p.id
        , b.playerID
        , b.id
        , s.toggle AS stoggle
        , o.toggle AS otoggle
        , p.city
        , p.school
        , s.city
        , s.school
        , r.opp_city
        , r.opp_school
        , o.city
        , o.school
        , r.city
        , r.school
        , p.grade
        , p.nameLast
    FROM a_players_reviews r 
    INNER JOIN a_players p ON CONCAT (r.nameFirst,r.nameLast) = CONCAT (p.nameFirst,p.nameLast)
    INNER JOIN a_player_bookmark b ON p.id = b.playerID AND '". $userID ."' = b.userID
    LEFT JOIN a_schools s ON CONCAT(r.city,r.school) = CONCAT(s.city,s.school)
    LEFT JOIN a_schools o ON CONCAT(r.opp_city,r.opp_school) = CONCAT(o.city,o.school)
    WHERE 
       b.bookmark > 0
    ORDER BY r.id desc
    LIMIT 15
) mostRecent
ORDER BY
    mostRecent.grade
    , mostRecent.nameLast

Some additional notes, if you're going to create a WHERE condition using columns from a joined table, you probably want to use INNER JOIN rather than LEFT JOIN unless you're accounting for NULL values.   In general you should use INNER JOIN always unless you have specific reason to use a LEFT JOIN.

Your p.id = b.playerID and '$userID' = b.userID conditions are duplicated between your join and WHERE clauses, you only need them in one place, and that is the ON clause so remove them from the WHERE.

You didn't qualify your bookmark column with a table but I'm assuming it probably belongs to the a_player_bookmark table (if that's wrong this advice may not apply).  If that's the case then your b.bookmark > 0 condition effectively means you're INNER JOINing that table since any null values would fail.  As such you can just convert that join to INNER JOIN.  If you're intentionally looking for players without a bookmark entry (where the join fails) then you need to make that condition part of the ON clause and use a LEFT JOIN.

 

Edited April 14, 2020 by kicken

[Jim R]

I'm getting a syntax error:

 

Quote

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'FROM a_players_reviews r INNER JOIN a_players p ON CONCAT (r.nameFirst' 

 

[Jim R]

Disregard.  I had an omission, but now I'm getting this error:

 

Quote

Duplicate column name 'id'

 

Edited April 14, 2020 by Jim R

[Jim R]

I set up the p.id as pid,  r.id as rid and b.id as bid  and now it says:

 

Quote

Unknown column 'pid' in 'on clause'
 

 

Edited April 14, 2020 by Jim R

[Jim R]

I've been searching for other samples on the Googles and play around with pid / p.id, I removed it from the SELECT, and the error moved to the next p. instance, 'p.city', saying it was a duplicate column name.  Removed all the p. columns, and it turned to having a duplicate city column.  

I removed all the column names in the sub select, leaving just * , and I was back to having duplicate column 'id'.  

 

Is it not seeing any of the aliases?  

[kicken]

10 hours ago, Jim R said:

Unknown column 'pid' in 'on clause'

You only use the aliases in the SELECT clause, not your joins or where clauses.  Continue to use p.id in those areas, but alias it in the select using p.id as pid

Since it's a sub-query each column in the SELECT has to have a unique name so alias any duplicates to something unique.  Then in your outer query you use the aliases instead of the original name.

Edited April 14, 2020 by kicken

[Jim R]

2 hours ago, kicken said:

You only use the aliases in the SELECT clause, not your joins or where clauses.  Continue to use p.id in those areas, but alias it in the select using p.id as pid

Since it's a sub-query each column in the SELECT has to have a unique name so alias any duplicates to something unique.  Then in your outer query you use the aliases instead of the original name.

But that gets me back to the duplicate column error.  I only messed around with the aliases because of that.  

 

So what you modified sent the duplicate column error.  

[kicken]

The code I posted needs to have aliases added to it as you discovered.  If after adding those you're still having issues then you need to post the code you are using after you've applied your modifications.

 

[Jim R]

Getting this error:

Unknown column 'rfirst' in 'on clause'

 

$query = "SELECT * FROM (SELECT *,p.id as pid,
		b.playerID as bplayerID,
		b.userID as buserID,
		s.toggle AS stoggle,
		o.toggle AS otoggle,
		p.city as pcity,
		p.school as pschool,
		s.city as scity,
		s.school as sschool,
		r.id as rid,
		r.opp_city as roppcity,
		r.opp_school as roppschool,
		o.city as ocity,
		o.school as oschool,
		r.city as rcity,
		r.school as rschool,
		r.nameFirst as rfirst,
		r.nameLast as rlast,
		p.nameFirst as pfirst,
		p.nameLast as plast
		
		FROM a_players_reviews r 
		
		LEFT JOIN a_players p 
			ON CONCAT (rfirst,rlast) = CONCAT (pfirst,plast)
	
		LEFT JOIN a_schools s 
			ON CONCAT(rcity,rschool) = CONCAT(scity,sschool)
		LEFT JOIN a_schools o	
		 	ON CONCAT(roppcity,roppschool) = CONCAT(ocity,oschool)
		
		LEFT JOIN a_player_bookmark b
			ON pid = bplayerID && '". $userID ."' = buserID
		
		WHERE bookmark>0
		ORDER BY rid desc
		LIMIT 15) mostRecent
 			ORDER BY mostRecent.grade,mostRecent.nameLast	
		";

 

[kicken]

36 minutes ago, Jim R said:

Getting this error:

Unknown column 'rfirst' in 'on clause'

And I told you:

5 hours ago, kicken said:

You only use the aliases in the SELECT clause, not your joins or where clauses.  Continue to use p.id in those areas, but alias it in the select using p.id as pid

The aliases are only for your SELECT and the outer query.  Continue using the table.column name syntax in your conditions and joins.

 

[Jim R]

Now I'm getting...

 

Duplicate column name 'id'
 

$query = "SELECT * FROM (SELECT *,p.id as pid,
		b.playerID as bplayerID,
		b.userID as buserID,
		s.toggle AS stoggle,
		o.toggle AS otoggle,
		p.city as pcity,
		p.school as pschool,
		s.city as scity,
		s.school as sschool,
		r.id as rid,
		r.opp_city as roppcity,
		r.opp_school as roppschool,
		o.city as ocity,
		o.school as oschool,
		r.city as rcity,
		r.school as rschool,
		r.nameFirst as rfirst,
		r.nameLast as rlast,
		p.nameFirst as pfirst,
		p.nameLast as plast
		
		FROM a_players_reviews r 
		
		LEFT JOIN a_players p 
			ON CONCAT (r.nameFirst,r.nameLast) = CONCAT (p.nameFirst,p.nameLast)
	
		LEFT JOIN a_schools s 
			ON CONCAT(r.city,r.school) = CONCAT(s.city,s.school)
		LEFT JOIN a_schools o	
		 	ON CONCAT(r.opp_city,r.opp_school) = CONCAT(o.city,o.school)
		
		LEFT JOIN a_player_bookmark b
			ON p.id = b.playerID && '". $userID ."' = b.userID
		
		WHERE bookmark>0
		ORDER BY r.id desc
		LIMIT 15) mostRecent
 			ORDER BY mostRecent.grade,mostRecent.nameLast	
		";

 

[kicken]

Get rid of the * in your select.

[Jim R]

Quote

Unknown column 'mostRecent.grade' in 'order clause'

 

 

At least we're working down the query. 🥴

Edited April 14, 2020 by Jim R

[kicken]

You need have whatever columns you want to order by in the outer query as part of the select clause of the inner query.  If you check my original query you'll see I added the grade and nameLast columns to the select list.

If you alias them, then use the alias in the order by clause of the outer query.

[Jim R]

6 minutes ago, kicken said:

You need have whatever columns you want to order by in the outer query as part of the select clause of the inner query.  If you check my original query you'll see I added the grade and nameLast columns to the select list.

If you alias them, then use the alias in the order by clause of the outer query.

 

I pasted your original query.  It yielded the same set of errors we're getting now, and the order by columns at the end were not in the original select list, certainly not with mostrecent.grade and mostrecent.nameLast.  Giving it a try.

Edited April 14, 2020 by Jim R

[Jim R]

I tried mostRecent.grade and mostRecent.nameLast in the inner select and outer select.  I tried them in both at the same time.  All three instances I got the following error:

 

Unknown column 'mostRecent.grade' in 'field list'

 

$query = "SELECT *,mostRecent.grade,
		mostRecent.nameLast
		
		FROM (SELECT p.id as pid,
		b.playerID as bplayerID,
		b.userID as buserID,
		s.toggle AS stoggle,
		o.toggle AS otoggle,
		p.city as pcity,
		p.school as pschool,
		s.city as scity,
		s.school as sschool,
		r.id as rid,
		r.opp_city as roppcity,
		r.opp_school as roppschool,
		o.city as ocity,
		o.school as oschool,
		r.city as rcity,
		r.school as rschool,
		r.nameFirst as rfirst,
		r.nameLast as rlast,
		p.nameFirst as pfirst,
		p.nameLast as plast
		
		
		FROM a_players_reviews r 
		
		LEFT JOIN a_players p 
			ON CONCAT (r.nameFirst,r.nameLast) = CONCAT (p.nameFirst,p.nameLast)
	
		LEFT JOIN a_schools s 
			ON CONCAT(r.city,r.school) = CONCAT(s.city,s.school)
		LEFT JOIN a_schools o	
		 	ON CONCAT(r.opp_city,r.opp_school) = CONCAT(o.city,o.school)
		
		LEFT JOIN a_player_bookmark b
			ON p.id = b.playerID && '". $userID ."' = b.userID
		
		WHERE bookmark>0
		ORDER BY r.id desc
		LIMIT 15) mostRecent
 			ORDER BY mostRecent.grade,mostRecent.nameLast	
		";

 

Edited April 14, 2020 by Jim R

[kicken]

 

You need to select the columns in your inner query.  Alias them if needed.

Then in the outer query is where you use them.  mostRecent is the name assigned to the results of the inner query so it is only valid in the outer query and you use it to reference whichever columns you select.