Question

i have the following, set of array and a mysql table ,table1

$arr1 = (“A0″,”A1″,”A2″,”A3″,”A4”)
$arr2 = (“B0″,”B1″,”B2″,”B3″,”B4”)

+----+-----------------+------+------+
| id | Col1            | Col2 | Col3 |
+----+-----------------+------+------+
|  0 | A0;B1;B2;       | x    | 9    |
|  1 | A0;B1;B2;A1;A2; | x    | 15   |
|  2 | A0;             | x    | 7    |
|  3 | B0;             | x    | 5    |
|  4 | C0;             | j    | 5    |
+----+-----------------+------+------+

is it possible that i can query the values in my table so that the final output will be something like this

    +----+-------+------+
    | id |  C31T | C32T |
    +----+-------+------+
    |  0 |  19   |  17  |
    +----+-------+------+

C31T and C32T was from this table

    +----+------+------ +-------+------+------+
    | id | Arr1 | Arr2  |  C31  | C32  | tot  |
    +----+------+-------+-------+------+------+
    |  0 | 1    | 2     |  3    |  6   | 3    |
    |  1 | 3    | 2     |  9    |  6   | 5    |
    |  2 | 1    | 0     |  7    |  0   | 1    |
    |  3 | 0    | 1     |  0    |  5   | 1    |
    +----+------+-------+-------+------+------+

Following eggyal solution i’m stuck up to this point

    SELECT   table1.id,
         COUNT(DISTINCT arr1.element) AS Arr1,
         COUNT(DISTINCT arr2.element) AS Arr2,
         COUNT(DISTINCT arr1.element) +
         COUNT(DISTINCT arr2.element) AS tot,
(COUNT(DISTINCT arr1.element)/(COUNT(DISTINCT arr1.element)+COUNT(DISTINCT arr2.element)))*col3 AS c31,
(COUNT(DISTINCT arr2.element)/(COUNT(DISTINCT arr1.element)+COUNT(DISTINCT arr2.element)))*col3 AS c32
FROM     table1
  LEFT JOIN (
    SELECT 'A0' AS element
    UNION ALL SELECT 'A1'
    UNION ALL SELECT 'A2'
    UNION ALL SELECT 'A3'
    UNION ALL SELECT 'A4'
  ) arr1 ON FIND_IN_SET(
    arr1.element,
    REPLACE(table1.Col1, ';', ',')
  )
  LEFT JOIN (
    SELECT 'B0' AS element
    UNION ALL SELECT 'B1'
    UNION ALL SELECT 'B2'
    UNION ALL SELECT 'B3'
    UNION ALL SELECT 'B4'
  ) arr2 ON FIND_IN_SET(
    arr2.element,
    REPLACE(table1.Col1, ';', ',')
  )
WHERE    table1.Col2 = 'x'
GROUP BY table1.id

Answer 1

I completely agree with @Kickstart’s comment—you really should normalise your schema:

CREATE TABLE associations (
  id      INT,
  element VARCHAR(2),
  FOREIGN KEY (id) REFERENCES table1 (id)
);

INSERT INTO associations
  (id, element)
VALUES
  (0, 'A0'), (0, 'B1'), (0, 'B2'),
  (1, 'A0'), (1, 'B1'), (1, 'B2'), (1, 'A1'), (1, 'A2'),
  (2, 'A0'),
  (3, 'B0'),
  (4, 'C0')
;

ALTER TABLE table1 DROP Col1;

Then your query would be:

SELECT   table1.id,
         COUNT(DISTINCT arr1.element) AS Arr1,
         COUNT(DISTINCT arr2.element) AS Arr2,
         COUNT(DISTINCT arr1.element) +
         COUNT(DISTINCT arr2.element) AS tot
FROM     table1 JOIN associations USING (id)
  LEFT JOIN (
    SELECT 'A0' AS element
    UNION ALL SELECT 'A1'
    UNION ALL SELECT 'A2'
    UNION ALL SELECT 'A3'
    UNION ALL SELECT 'A4'
  ) arr1 USING (element)
  LEFT JOIN (
    SELECT 'B0' AS element
    UNION ALL SELECT 'B1'
    UNION ALL SELECT 'B2'
    UNION ALL SELECT 'B3'
    UNION ALL SELECT 'B4'
  ) arr2 USING (element)
WHERE    table1.Col2 = 'x'
GROUP BY table1.id

Results:

| ID | ARR1 | ARR2 | TOT |
--------------------------
|  0 |    1 |    2 |   3 |
|  1 |    3 |    2 |   5 |
|  2 |    1 |    0 |   1 |
|  3 |    0 |    1 |   1 |

Without such a normalised schema, the “quite hideous coding” to which (s)he referred would be:

SELECT   table1.id,
         COUNT(DISTINCT arr1.element) AS Arr1,
         COUNT(DISTINCT arr2.element) AS Arr2,
         COUNT(DISTINCT arr1.element) +
         COUNT(DISTINCT arr2.element) AS tot
FROM     table1
  LEFT JOIN (
    SELECT 'A0' AS element
    UNION ALL SELECT 'A1'
    UNION ALL SELECT 'A2'
    UNION ALL SELECT 'A3'
    UNION ALL SELECT 'A4'
  ) arr1 ON FIND_IN_SET(
    arr1.element,
    REPLACE(table1.Col1, ';', ',')
  )
  LEFT JOIN (
    SELECT 'B0' AS element
    UNION ALL SELECT 'B1'
    UNION ALL SELECT 'B2'
    UNION ALL SELECT 'B3'
    UNION ALL SELECT 'B4'
  ) arr2 ON FIND_IN_SET(
    arr2.element,
    REPLACE(table1.Col1, ';', ',')
  )
WHERE    table1.Col2 = 'x'
GROUP BY table1.id

Results:

| ID | ARR1 | ARR2 | TOT |
--------------------------
|  0 |    1 |    2 |   3 |
|  1 |    3 |    2 |   5 |
|  2 |    1 |    0 |   1 |
|  3 |    0 |    1 |   1 |

UPDATE

Following your edit, you merely need to perform an outer query on this existing one:

SELECT SUM(Arr1/tot) AS C31T, SUM(Arr2/tot) AS C32T
FROM (

  SELECT   COUNT(DISTINCT arr1.element) * table1.Col3 AS Arr1,
           COUNT(DISTINCT arr2.element) * table1.Col3 AS Arr2,
           COUNT(DISTINCT arr1.element) +
           COUNT(DISTINCT arr2.element) AS tot
  FROM     table1
    LEFT JOIN (
      SELECT 'A0' AS element
      UNION ALL SELECT 'A1'
      UNION ALL SELECT 'A2'
      UNION ALL SELECT 'A3'
      UNION ALL SELECT 'A4'
    ) arr1 ON FIND_IN_SET(
      arr1.element,
      REPLACE(table1.Col1, ';', ',')
    )
    LEFT JOIN (
      SELECT 'B0' AS element
      UNION ALL SELECT 'B1'
      UNION ALL SELECT 'B2'
      UNION ALL SELECT 'B3'
      UNION ALL SELECT 'B4'
    ) arr2 ON FIND_IN_SET(
      arr2.element,
      REPLACE(table1.Col1, ';', ',')
    )
  WHERE    table1.Col2 = 'x'
  GROUP BY table1.id

) t

Results:

| C31T | C32T |
---------------
|   19 |   17 |