Question

I have a KVP Table and the structure is ID, Key, Value.

Here are some example values…

ID, KEY,       VALUE
---------------------
 1, STATUS,    TRUE
 1, AGE GROUP, 10
 1, TRAVEL,    Y
 2, STATUS,    FALSE
 2, AGE GROUP, 20
 2, TRAVEL,    N

I want these values to be transformed as below…

ID, STATUS, AGE GROUP, TRAVEL
------------------------------
 1, TRUE,   10,        Y
 2, FALSE,  20,        N

I have read about crosstab/pivot, but I’m not able to make a query which can give me the above output. Is there any way in SQL to make my output look like the above example?

Answer 1

There are probably optimizations, but this works (tested in SQLite and MySQL)

select stat.id as id, status, age_group, travel from 
(select id, Value as status from kvp
where Key = 'STATUS') as stat JOIN
(select id, Value as age_group from kvp
where Key = 'AGE GROUP') as age on stat.id = age.id JOIN
(select id, Value as travel from kvp
where Key = 'TRAVEL') as trav on stat.id = trav.id;

Edited to fix a possible ambiguity.