问题
i am using H2-DB to access static databases...
i have a table which looks like:
COUNTRY STATE CITY LAT LNG COUNTRYID STATEID CITYID
"Germany" "Berlin" "" 1.23 1.23 1 1 0
"Germany" "München" "" 1.23 1.23 1 2 0
"USA" "Alabama" "Auburn" 1.23 1.23 2 1 1
"USA" "Alabama" "Birmingham" 1.23 1.23 2 1 2
"USA" "Alaska" "Anchorage" 1.23 1.23 2 2 1
"USA" "Alaska" "Cordova" 1.23 1.23 2 2 2
its a huge list with lots of countries, most of them just have Country and State (like Germany here, whereas State's are Cities), a few also have a City (like USA here)...
the problem is now, when i query
SELECT * FROM MyTable WHERE COUNTRY = 'Germany' group by STATE order by STATE
to get a sorted list of the states (or cities), i get an error saying
Field CITY must be in the GROUP BY list
if the row has a city, i need the whole row, otherwise i would only need the State column, but i can just know after having queried it, wether it uses the city column or not, so i have to query "*" instead of "STATE"
the query should be okay, or? On MySql it is properly working... so whats the problem here?
Found this if it helps: http://www.h2database.com/javadoc/org/h2/constant/ErrorCode.html#c90016
Metin
回答1:
MySQL is broken in regards to this. It allows columns in the GROUP BY that are neither in the group by nor arguments to aggregation functions. In fact, the documentation warns against using this extension.
So you can do:
SELECT state
FROM DIYANET
WHERE COUNTRY = 'Germany'
GROUP BY STATE
ORDER BY STATE;
Or something like this:
SELECT state, min(city), min(lat), . . .
FROM DIYANET
WHERE COUNTRY = 'Germany'
GROUP BY STATE
ORDER BY STATE;
But SELECT * is not allowed and doesn't really make sense.
来源：https://stackoverflow.com/questions/31596497/h2-db-column-must-be-in-group-by-list