带COUNT个查询的MySQL CASE

Question

I asked a similar question before but I realized my desired output is totally different.

I have the following query

SELECT LEVEL, COUNT(*) AS total FROM admin_xxx
GROUP BY LEVEL ORDER BY total DESC LIMIT 10

Table output

Level  Total
4       27
3       24
7       19
5       10
8       9
6       7
1       5
2       3

Now I just want to rename the actual level with words instead of numbers.

I would like to following as output

Level     Total
Bronze      27
Silver      24
Gold        19
Gold2       10
Gold3       9
Gold4       7
Gold5       5
Gold6       3

Each 10 levels have a separate level name.

I tried the following but get syntax error

SELECT LEVEL, COUNT(*) AS total FROM admin_xxx
CASE
WHEN LEVEL = 1 THEN "Bronze",
etc...
WHEN LEVEL = 10 THEN "Gold10"
  END as LEVEL

GROUP BY LEVEL ORDER BY total DESC LIMIT 10

Answer 1

Change your GROUP BY to

GROUP BY (
    CASE
        WHEN LEVEL = 1 THEN "Bronze",
        etc...
        WHEN LEVEL = 10 THEN "Gold10"
    END
)

You also have syntax error on your SELECT

SELECT (
    CASE
        WHEN LEVEL = 1 THEN "Bronze",
        etc...
        WHEN LEVEL = 10 THEN "Gold10"
    END
) AS LEVEL
     , COUNT(*) AS total 
FROM admin_xxx
GROUP BY (
    CASE
        WHEN LEVEL = 1 THEN "Bronze",
        etc...
        WHEN LEVEL = 10 THEN "Gold10"
    END
)
ORDER BY total DESC LIMIT 10

Answer 2

you have from clause in the wrong position

  SELECT 
      CASE
        WHEN LEVEL = 1 THEN "Bronze" 

        WHEN LEVEL = 10 THEN "Gold10"
      END as  LEVEL
    , COUNT(*) AS total 
  FROM admin_xxx
  GROUP BY LEVEL ORDER BY total DESC LIMIT 10

Answer 3

You can also separate yours levels/labels to another table, and you can join these. For example:

SELECT levels.level_label, COUNT(*) AS total 
FROM admin_xxx
LEFT JOIN levels ON levels.label_value = admin_xxx.level
GROUP BY levels.level_label ORDER BY total DESC LIMIT 10

And this is the levels table:

id  level_label     label_value
1   Bronze          10
2   Silver          9
3   Gold            1
4   Gold2           2
5   Gold3           3
6   Gold4           4
7   Gold5           5
8   Gold6           6
9   Gold7           7
10  Gold8           8

Answer 4

TRY THIS: Obviously you should use CASE in the following way to achieve the desired output

SELECT CASE level 
        WHEN 1 THEN 'Bronze'
        WHEN 2 THEN 'Silver'
        WHEN 3 THEN 'Gold'
        WHEN 4 THEN 'Gold2'
        WHEN 5 THEN 'Gold3'
        WHEN 6 THEN 'Gold4'
        WHEN 6 THEN 'Gold5'
        WHEN 6 THEN 'Gold6'
        ELSE 'Unknown' END Level, 
    COUNT(*) AS total 
FROM admin_xxx
GROUP BY level 
ORDER BY total DESC LIMIT 10