Doctrine DQL: Select entities having children/relations to FK table -

-

assuming setup 

teachers (id, name) students (id, name, teacher [fk]);

how select in dql teachers have students? guess like

select t entities\teachers t count(t.students) > 0

but know count(t.students) > 0 wrong ... use then?

update

now abt many many self referencing relationship? user can teacher or student or both ... code below ... whats dql getting users have students?

/** @entity @table(name="users")) */ class user {     /**      * @id @column(type="integer")      * @generatedvalue(strategy="auto")      */     private $id;     /**      * @column(type="string", length="30")      */     private $name;     /**      * @manytomany(targetentity="user", inversedby="teachers")      * @jointable(name="teachers_students",      *              joincolumns={@joincolumn(name="teacher", referencedcolumnname="id")},      *              inversejoincolumns={@joincolumn(name="student", referencedcolumnname="id")}      *              )      */     private $students;     /**      * @manytomany(targetentity="user", mappedby="students")      */     private $teachers;

you can use join in case.

select t entities\teachers t  innerjoin entities\students s on t.id = s.teacher

if can set base follows can handle case easily. far experience know doctrine can handle many many relation within best way.

$this->hasmany('user students', array(          'local'     => 'id',          'foreign'   => 'student_id',          'refclass'  => 'usertostudents',          'ondelete'  => 'cascade'));  $this->hasmany('user teachers', array(          'local'     => 'id',          'foreign'   => 'teacher_id',          'refclass'  => 'usertoteachers',          'ondelete'  => 'cascade'));

thanks


Comments

Post a Comment

Popular posts from this blog

c++ - How do I get a multi line tooltip in MFC -

-
right now, have tool tip pops when hover on edit box. problem tool tip contains multiple error messages , in 1 long line. need have each error message on own line. error messages contained in cstring new line seperating them. my existing code below. bool ontooltiptext(uint, nmhdr* pnmhdr, lresult* presult) { assert(pnmhdr->code == ttn_needtexta || pnmhdr->code == ttn_needtextw); // need handle both ansi , unicode versions of message tooltiptexta* pttta = (tooltiptexta*)pnmhdr; tooltiptextw* ptttw = (tooltiptextw*)pnmhdr; // tchar szfulltext[256]; cstring strtiptext=_t(""); uint nid = pnmhdr->idfrom; if (pnmhdr->code == ttn_needtexta && (pttta->uflags & ttf_idishwnd) || pnmhdr->code == ttn_needtextw && (ptttw->uflags & ttf_idishwnd)) { // idfrom hwnd of tool nid = ::getdlgctrlid((hwnd)nid); } //m_errprojaccel[ch] contains 1 or more error messages each...
Read more

asp.net - In javascript how to find the height and width -

-
i having .aspx , masterpage page. in masterpage loading aspx page . in aspx page design using generating table structure using code-behind server in javascript how find height , width . regards, kumar if you're looking table height , width, should it var tbl = document.getelementbyid('tbldemo'); alert(tbl.offsetwidth + '\n' + tbl.offsetheight);
Read more

c# - DataTable to EnumerableRowCollection -

-
i have datatable according client requirement can contain invalid date "00/00/1999",null,empty string.(typed datset) when collect them enumerables wish convert of invalid forms empty string. (i.e) enumerablerowcollection<datarow> query = order in _table.asenumerable() select new { orderdate= string.isnullorempty(convert.tostring(order.field<datetime>("orderdate")) || (how check date invalid date) ? string.empty : order.field<datetime>("orderdate") } how check whether date valid date or not? datetime.tryparse...like given current code: datetime date; enumerablerowcollection<datarow> query = order in _table.asenumerable() select new { orderdate= string.isnullorempty(convert.tostring(order.field<datetime>("orderdate")) || !datetime.tryparse(convert.tostring(order.field<datetime...
Read more