问题
Quite basic, but I am stuck at the moment.
On an Informix database (no pivot option), I am searching for a dynamic way to transform the following table using SQL:
book | info | value ----------------------------- Moby Dick | price | high Moby Dick | stock | few Hamlet | price | low Hamlet | stock | many Faust | price | medium Faust | stock | normal
Resulting table:
book | price | stock ----------------------------- Moby Dick | high | few Hamlet | low | many Faust | medium | normal
Thanks for your help!
回答1:
You can aggregate based on CASE expression grouped by book. Try something like this.
SELECT book,
MAX(CASE WHEN info = 'price' THEN value END) as price,
MAX(CASE WHEN info = 'stock' THEN value END) as stock
FROM table1
GROUP BY book
来源：https://stackoverflow.com/questions/38246875/sql-select-transform-rows-in-columns