mysql - Combining two tables in a complex way -

-

the situation:

i have main table, lets call maintable.

+---------+----------+----------+----------+  |  id (pk)| title    | text     | type     | +---------+----------+----------+----------+  |   1     | text|more stuff|        |  |   2     |  | example  | b        |  +---------+----------+----------+----------+

and have second table called translationstable, in id field representation of maintable row id (no foreign key, can refering different tables), objtype objecttype (same name table), fieldname name of field objectype , value has translation value fieldname value in objtype table.

+---------+-----------+-----------+------------+----------+ |   id    | objtype   | fieldname | value      | language | +---------+-----------+-----------+------------+----------+ |   1     | maintable | title     | algum texto| pt       | |   1     | maintable | text      | mais coisas| pt       | +---------+-----------+-----------+------------+----------+

and because need search in translated fields, figured use temporary table so, came problem of "which select query should use?". read posts pivot table queries, i don't know how can build query temp table like

+---------+------------+------------+----------+  |  id (pk)| field_1    | field_2    | field_3  | +---------+------------+------------+----------+  |   1     | algum texto| mais coisas|        |   +---------+------------+------------+----------+

thank you.

edit:

i accepted ad7six answer because 500.000 entries in maintable , 1.500.000 in translations 30x times faster other one.

that's not complex

it's query 1 join per translated field.

that means query/sort/whatever other e.g. (using real names it's easier read):

select     products.id,     coalesce(product_name.value, products.name) name,     coalesce(product_description.value, products.description) description     products left join     translationstable product_name     on (         product_name.language = 'pt' ,         product_name.objecttype = 'products' ,         product_name.fieldname = 'name' ,         product_name.id = products.id     ) left join     translationstable product_description     on (         product_description.language = 'pt' ,         product_description.objecttype = 'products' ,         product_description.fieldname = 'description' ,         product_description.id = products.id     )     product_name.value = "algum texto" // find products named "algum texto"

you don't need temp table

but if want create one, it's easy using query itself:

create table     products_pt select     products.id,     coalesce(product_name.value, products.name) name,     coalesce(product_description.value, products.description) description ...

this create table (no indexes) matching structure of query. if data not change can make querying multilingual data lot easier manage, has disadvantages such (obviously) translation-specific table not date if source table data changes.


Comments

Post a Comment

Popular posts from this blog

ios - Memory not freeing up after popping viewcontroller using ARC -

-
hi project arc based, using uinavigationcontroller make transition between viewcontroller. using profiler analyse happening behind scene memory. noticed when push viewcontroller allocate memory components , when pop not freeing allocated memory. since using arc unable implement dealloc or release component. have analysed in detail , there no memory leak in project. i not using strong property push viewcontroller. here how pushing viewcontroller. viewcontroller *obj = [[viewcontroller alloc] init]; [self.navigationcontroller pushviewcontroller:obj animated:no]; any clue whats going on? should free memory have consumed. please advise your description indicates have retain cycle, leads objects not being deallocated. typical source of retain cycles properties assigned loading nib files (usually declared iboutlet ). two strategies break them , release objects: declare property weak : @property (nonatomic, weak) iboutlet uilabel *statuslabel; set property nil in...
Read more

Django REST Framework perform_create: You cannot call `.save()` after accessing `serializer.data` -

-
i have following viewset: class artistprofileviewset(viewsets.modelviewset): queryset = artistprofile.objects.all() serializer_class = artistprofileserializer def perform_create(self, serializer): if serializer.is_valid(): serializer.save() with following serializers: class simpleartisttrackserializer(serializers.hyperlinkedmodelserializer): class meta: model = artisttrack fields = (...my fields...) class artistprofileserializer(serializers.hyperlinkedmodelserializer): owners = userserializer(many=true, required=false) tracks = simpleartisttrackserializer(many=true, required=false) class meta: model = artistprofile fields = (...my fields...) i getting following error: assertionerror: cannot call `.save()` after accessing `serializer.data`.if need access data before committing database inspect 'serializer.validated_data' instead. i don't see editing serializer.data object. th...
Read more

Why does Go error when trying to marshal this JSON? -

-
i'm trying rather simple example of trying decode json file structs using golang. however, when attempting error that json: cannot unmarshal object go value of type []main.track which don't understand. here's code in question, , json can found here . package main import ( "encoding/json" "fmt" "net/http" "os" ) // tracks group of track types type tracks struct { tracks []track } // track represents singular track type track struct { name string url string artist artist } // artist represents single artist type artist struct { name string mbid string url string } func main() { url := "http://ws.audioscrobbler.com/2.0/?method=geo.gettoptracks&api_key=c1572082105bd40d247836b5c1819623&format=json&country=netherlands" response, err := http.get(url) if err != nil { fmt.printf("%s\n", err) os.exit(1) } de...
Read more