SQL Trying to select only the first record out of several returned -

-

i have query returns students , roommates. idea have show in first column , column 2 , 3 have each roommate. column 3 blank, columns 1 , 2 have results.

my query returning correct data exception of when there 3 people in room, more 1 record. such below.

_roommate1  roommate2 roommate3  room1_    _roommate1  roommate3 roommate2  room1_   _roommate2  roommate1 roommate3  room1_   _roommate2  roommate3 roommate1  room1_    _roommate3  roommate1 roommate2  room1_   _roommate3  roommate2 roommate1  room1_

all want keep first instance of each row when field appears in column 1.

so reduce output to: 

_roommate1  roommate2 roommate3  room1_   _roommate2  roommate1 roommate3  room1_   _roommate3  roommate1 roommate2  room1_

the intent send form letter each person in column 1 tell them names of roommates.

since can use distinct on row , not on field, @ temporary loss how might able this. able if worked is:

select (distinct column1), column2, column3 first instance of each column1. suggestions?

sounds group might useful?

http://www.w3schools.com/sql/sql_groupby.asp


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