MySQL数据透视表 - 将行转换为列

Question

This is the structure of my table:

Then I run a query

SELECT `date`,`index_name`,`results` FROM `mst_ind` WHERE `index_name` IN ('MSCI EAFE Mid NR USD', 'Alerian MLP PR USD') AND `time_period`='M1'

and get a table like

How can I convert "index_name" rows to columns like:

date | MSCI EAFE Mid NR USD | Alerian MLP PR USD etc

In other words I need each column to represent an index and rows to represent date-result. I understand that MySQL doesn't have pivot table functions. What is the easiest way of doing this?

I've tried this code, but it generates an error:

SELECT
  `date`,
  MAX(IF(index_name = 'Alerian MLP PR USD' AND `time_period`='M1', results, NULL)) AS res1,
  MAX(IF(index_name = 'MSCI EAFE Mid NR USD' AND `time_period`='M1', results, NULL)) AS res2
FROM
  `mst_ind`
GROUP BY `date

I need to make the conversion on the query level - not PHP. Please suggest a nice and elegant solution. Thanks!

Answer 1

Try

SELECT date,
       MAX(CASE WHEN index_name = 'Alerian MLP PR USD' THEN results END) `Alerian MLP PR USD`,
       MAX(CASE WHEN index_name = 'MSCI EAFE Mid NR USD' THEN results END) `MSCI EAFE Mid NR USD`
  FROM mst_ind
 WHERE index_name IN ('MSCI EAFE Mid NR USD', 'Alerian MLP PR USD') 
   AND time_period = 'M1'
 GROUP BY date

Sample output:

|       DATE | ALERIAN MLP PR USD | MSCI EAFE MID NR USD |
|------------|--------------------|----------------------|
| 1995-01-31 |            -0.0167 |               0.0335 |
| 1995-02-28 |             0.0128 |               0.0409 |
| 1995-03-31 |             0.0464 |               0.0286 |
| 1995-04-28 |             0.0331 |               0.0297 |
| 1995-05-31 |             0.0069 |               0.0398 |
...

Here is SQLFiddle demo