gorm - How to implements tablePerHierarchy with disciminator in grails? -

-

i have class hirarchy :

class item {} class participation extends item{} class contribution extends participation{} class question extends participation{}

i have table per class so, add tableperhierarchy false in item

i need discrimator implements query : class = "contribution"

i try lot of implementation it's not working.

how ?

thanks

do want table per hierarchy or table per class? it's not clear in question.

with following domain objects, can either way:

// item.groovy class item {     string x }  // participation.groovy class participation extends item {                         string y }

using default, table per hierarchy strategy, 1 table used store items , subclasses of items too. default discriminator column called class, grails use automatically. schema generated grails schema-export looks this:

create table item (     id bigint generated default identity (start 1),      version bigint not null,      x varchar(255) not null,     class varchar(255) not null,     y varchar(255),     primary key (id) );

there's 1 table both classes contains fields declared in every class in hierarchy plus discriminator column class. if query participation.list(), sql grails generates looks this:

select     this_.id id1_0_,     this_.version version1_0_,     this_.x x1_0_,     this_.y y1_0_     item this_     this_.class='participation'

by changing inheritance strategy table per class static mapping { tableperhieracrchy false } in item.groovy, grails generate table each of classes in hierarchy. each table stores fields declared in each class, participation object represented row in both item table , participation table. schema looks this:

create table item (     id bigint generated default identity (start 1),     version bigint not null,     x varchar(255) not null,     primary key (id) );  create table participation (     id bigint not null,     y varchar(255) not null,     primary key (id) );

and sql participation.list() changes to:

select     this_.id id1_0_,     this_1_.version version1_0_,     this_1_.x x1_0_,     this_.y y2_0_     participation this_ inner join     item this_1_         on this_.id=this_1_.id

Comments

Post a Comment

Popular posts from this blog

c# - How to set Z index when using WPF DrawingContext? -

-
how set z-index drawing object when using drawingcontext.drawxxx() methods? the object drawn last have higher z index. can't change index of drawn objects. way draw in order. if using wpf (as placed tag), can use, example, canvas control. create shapes need like polyline obj = new polyline(); //... // ... set properties of obj and add them canvas uielementcollection: yourcanvasname.children.add(obj); //or yourcanvasname.children.insert(i, obj); first items of collection have higher z index. advantages in way: no need redraw on window changes, can anytime move objects , change order.
Read more

razor - Is this a bug in WebMatrix PageData? -

-
i think may have found bug in webmatrix's pagedata, not sure. concerns how pass data partial page calling page. in webmatrix documentation (tutorials, e.g. " 3 - creating consistent look ", , example code), pagedata recommended mechanism pass data between pages (e.g. content page layout page, or partial page). however have found not work other way, pass data partial page calling page. modifying or adding entries in pagedata in partial page, not seem calling page. cutting right down simplest possible example, in test page may have this: @{ pagedata["test"] = "initial entry"; } <p>before calling partial page, test value @pagedata["test"]</p> @renderpage("_testpartial.cshtml") <p>after returning calling page, test value @pagedata["test"]</p> and in _testpartial.cshtml page might have this: @{ pagedata["test"] = "modified entry"; } <p>in partial page...
Read more

visual c++ - Using relative values in array sorting ( asm ) -

-
i need sort through array , sort each individual row in array in ascending order. doesn't seem going (surprise!) keep getting hit 2 errors: a2101: cannot add 2 relocatable labels , a2026: constant expected here's sort, makes sense me, think i'm still trying implement high-lvl language techniqes assembly. there way around not being able use relative values? (the array 7 rows 9 columns, btw). mov cx, 7; cx = number of rows outer: ; outer loop walk through rows push cx mov cx, 9 mov row, cx ;rows middle: ; middle-loop walk through columns push cx sub cx, 1 ;cx = cx-1 mov column, cx ;columns inner: ;inner loop - compare , exchange column values cmp marray[row*9 + column], marray[row*9 + column+1] xchg marray[row*9 + column+1], marray[row*9 + column] ; compare , exchange values marray table inc column loop inner pop cx loop mid...
Read more