Lead and Lag in SQL -

-

my table has following columns: product_id, customer_id, start_date, end_date, product, product_use. goal find product customer using @ beginning of each month end of each month? ideas how in sql? thanks.

product_id   cust_id    start_dt    end_dt 8398d           8678    12/18/2013  3/10/2014 270b9           8678    2/14/2014   3/16/2014 c0867           8678    3/25/2014   4/1/2014 2f9d2           8678    4/3/2014    5/7/2014 9ae65           8678    4/25/2014   5/6/2014

expected results

month    product_begining_of_month     product_end_of_month  december        8398d                  8398d january         8398d                  8398d february        8398d                  8398d , 270b9   march           8398d , 270b9        c0867 april           2f9d2                  2f9d2 , 9ae65

you select ids, , first , last dates result set; use outer table query these results select productid using inner table results of dates , customerid.. 

  select custid, (select product_id customertable ctbl2   (custid=inntbl.custid ,  (transcationdate=inntbl.lastmostdate)) lastmostproduct, (select product_id customertable ctbl3    (custid=inntbl.custid_ , (transcationdate=inntbl.firstdate)) firstproduct           (select custid, max(transcationdate) lastmostdate,     min(transcationdate) firstdate customertable ctbl    group custid) inntbl

Comments

Post a Comment

Popular posts from this blog

php - render data via PDO::FETCH_FUNC vs loop -

-
i've been using 2 methods render data. the first one: function name($id,$name){ return '<div id="'.$id.'">'.$name.'</div>'; } echo implode($pdo->query("select id,name user")->fetchall(pdo::fetch_func,'name')); the second one: $users = $pdo->query("select id,name user")->fetchall(pdo::fetch_obj); foreach($users $user){ echo name($user->id,$user->name); } i don't understand how pdo::fetch_func works. tried figure out. however, not well-documented. could please explain fetch mode? , also, 1 performs better? thank you. both methods wrong , have learn how use templates , how separate business logic presentation logic. $users = $pdo->query("select id,name user")->fetchall(pdo::fetch_obj); tpl::assign('users', $users); is code business logic part. then in template <?php foreach $users $row): ?> <div id="<?=$...
Read more

c++ - OpenCV Error: Assertion failed <scn == 3 ::scn == 4> in unknown function, -

-
i read alot other solution still confused should mine... #include <opencv2/objdetect/objdetect.hpp> #include <opencv2/highgui/highgui.hpp> #include <opencv2/imgproc/imgproc.hpp> #include <iostream> #include <stdio.h> using namespace std; using namespace cv; int main(int argc, const char** argv) { //create cascade classifier object used face detection cascadeclassifier face_cascade; //use haarcascade_frontalface_alt.xml library face_cascade.load("haarcascade_frontalface_alt.xml"); //setup video capture device , link first capture device videocapture capturedevice; capturedevice.open(0); //setup image files used in capture process mat captureframe; mat grayscaleframe; //create window present results namedwindow("outputcapture", 1); //create loop capture , find faces while (true) { //capture new image frame capturedevice >> captureframe; ...
Read more

The canvas has been tainted by cross-origin data in chrome only -

-
uncaught securityerror: failed execute 'getimagedata' on 'canvasrenderingcontext2d': canvas has been tainted cross-origin data i getting above error in chrome. code(following) works fine in mozilla. have not corss domain issue. why above error in chrome? var wheel_canvas, wheel_context, can_w, can_h, wheel_grd; var large_radius = 160; var small_radius = 120; var wheel_canvas = document.getelementbyid('wheel_canvas'); var wheel_context = wheel_canvas.getcontext('2d'); var can_w = $(wheel_canvas).width(); var can_h = $(wheel_canvas).height(); var centerx = can_w / 2, centery = can_h / 2; var wheel_grd = null; test('#ff0000'); function test(hex) { $('#clrpicker').css({'left': 210, 'top': 210 }); inverted = hexbw(hex); $('#color_val_show').val(hex); current_color_hex_val_selected = hex; $('#color_val_show').css({'color':inverted,'background':hex}); fillgradient...
Read more