Wrong Query MySQL selecting the record with oldest or newest Date -


i need know how obtain code of access (idaccess) older (or more recent) date of access user (identified iduser) made table accesstbl using different queries. each user.

create table accesstbl (  idacess varchar(16) unique not null,  iduser varchar(16) not null, thedate date not null  ); insert accesstbl (idacess, iduser, thedate) values  ('a00', '0', '1983-12-30'),  ('a01', '0', '2004-09-09'),  ('a02', '1', '2013-02-01'),  ('a03', '1', '2012-05-09'),  ('a04', '2', '1983-12-30'),  ('a13', '2', '2013-03-01'),  ('a05', '2', '2004-09-09'),  ('a06', '3', '2013-02-01'),  ('a07', '3', '2012-05-09'),  ('a08', '4', '1983-12-30'),  ('a09', '4', '2004-09-09'),  ('a10', '5', '2013-04-01'),  ('a12', '5', '2013-03-01'),  ('a11', '5', '2012-05-01');

example:

the user 5 recent 'a10' , oldest 'a11' user 4 recent 'a09' , oldest 'a08'

but, need newest date of users in 1 query.

i tried with...

select idacess, iduser, thedate accesstbl (   thedate in (select max(thedate) accesstbl  group iduser) )  group iduser;

but have:

+---------+--------+ | idacess | iduser | +---------+--------+ | a01     | 0      | | a02     | 1      | | a05     | 2      |  //bad!!!!! must a13 | a06     | 3      | | a09     | 4      | | a10     | 5      | +---------+--------+ 6 rows in set (0.13 sec)

later, tried with:

select idacess, iduser, max(thedate) accesstbl group iduser;

having...

+---------+--------+--------------+ | idacess | iduser | max(thedate) | +---------+--------+--------------+ | a00     | 0      | 2004-09-09   | //must a01 | a02     | 1      | 2013-02-01   |  | a04     | 2      | 2013-03-01   | //must a13 | a06     | 3      | 2013-02-01   | | a08     | 4      | 2004-09-09   | //must a09 | a10     | 5      | 2013-04-01   | +---------+--------+--------------+ 6 rows in set (0.00 sec)

thank valuable help.

ann

if want both oldest , newest simultaneously, you'll need use subqueries compare existing dates (filtered iduser) selected min , max date.

select idacess accesstbl iduser = ? , (   thedate in (select max(thedate) accesstbl iduser = ?)   or thedate in (select min(thedate) accesstbl iduser = ?) )

http://sqlfiddle.com/#!2/38594/20/0


Comments

Post a Comment

Popular posts from this blog

Why does Ruby on Rails generate add a blank line to the end of a file? -

running rails generate controller foo home results in: class foocontroller < application controller def home end end (there's nothing on line in actual file, blank line) is there purpose blank line? it's common use newline indicate end of line, last line. many editors (like vi, use) add in newline silently. consensus text files (especially in unix world) should end in newline, , there have been problems historically if wasn't present. why should text files end newline? the tool used count lines in file "wc" counts newlines in file, without trailing newline show 3 instead of 4. it improves readability of templates used in generator. consider: https://github.com/rails/rails/blob/master/railties/lib/rails/generators/rails/controller/templates/controller.rb to remove trailing newline, template have last line of: end<% end -%> instead of: end <% end -%> that seems less readable me. the discussion below refers
Read more

keyboard - Smiles and long press feature in Android -

i've created android keyboard. how add features inserting smilies, , using long keypresses display symbols? to create long-press behavior allows select several options pop-up menu, follow guide (specifically pop-up menu section): http://developer.android.com/guide/topics/ui/menus.html smileys (also known emoticons) combination of keys, understood programs , parsed same way. have do, when clicks smiley face on keyboard, simulate pressing of key combination matching emoticon. example, when clicks smiley, should simulate key presses ':' , ')' :). here's list of emoticons: http://en.wikipedia.org/wiki/list_of_emoticons
Read more

node.js - Bad Request - node js ajax post -

i'm using express 3.0 , node v0.11.0. have button submits form , i'm using ajax post data json object node server. client code is: $('#contact').submit(function(e) { console.log('submit called'); var formdata = json.stringify($('form').serializeobject()); console.log(formdata); $.ajax({ url: "http://localhost:3000/savedata/", type: "post", datatype: 'json', data: {objectdata: formdata}, contenttype: "application/json", complete: function() { console.log('process complete'); }, success: function(data) { console.log('process sucess'); }, error: function() { console.log('process error'); }, }); return false; }); then on server: var express = require('express'); var app = express(); app.set('views', __dirname + '/views'); app.set('view engine', 'jade'); app.use(express.bodyparser());
Read more