Subquery in MySQL View with GROUP -


i'm trying build view using code:

select *  `ergebnis` left join (     select `nr` `messwert_nr`, `ergebnisnummer`,`teststepreihenfolge`, `messbezeichnung`, `step_bezeichnung`, `messwert`, `messergebnis`     (         select *         `messwerte`         order `nr` desc         ) `f_messwerte`     group `ergebnisnummer`,`teststepreihenfolge`     order `ergebnisnummer`,`teststepreihenfolge` ) `t_messwerte` on (`t_messwerte`.`ergebnisnummer` = `ergebnis`.`nr`) order `nr` desc,`teststepreihenfolge`;

as can see, relies heavily on order instruction in messwerte on grouped by. subqueries not allowed in views.

assuming source table:

nr  ergebnisnummer  teststepreihenfolge messwert 1   1               1                   80 2   1               1                   86 3   1               2                   306 4   1               2                   302 5   1               2                   304 6   1               3                   0.2 7   2               1                   81 8   2               1                   79 9   2               1                   80 10  2               2                   305 11  2               2                   301 12  2               3                   0.1 13  2               3                   0.3

this want:

nr  ergebnisnummer  teststepreihenfolge messwert 13  2               3                   0.3 11  2               2                   301 9   2               1                   80 6   1               3                   0.2 5   1               2                   304 2   1               1                   86

i tried using multiple views, order alway lost, , didn't entry highest nr.

could give me hint on how solve this?

thanks in advance!

 drop table if exists my_table;   create table my_table  (nr  int not null auto_increment primary key  ,ergebnisnummer  int not null  ,teststepreihenfolge int not null  ,messwert decimal(5,2) not null  );   insert my_table values  (1   ,1               ,1                   ,80),  (2   ,1               ,1                   ,86),  (3   ,1               ,2                   ,306),  (4   ,1               ,2                   ,302),  (5   ,1               ,2                   ,304),  (6   ,1               ,3                   ,0.2),  (7   ,2               ,1                   ,81),  (8   ,2               ,1                   ,79),  (9   ,2               ,1                   ,80),  (10  ,2               ,2                   ,305),  (11  ,2               ,2                   ,301),  (12  ,2               ,3                   ,0.1),  (13  ,2               ,3                   ,0.3);   select x.*     my_table x     join        ( select ergebnisnummer              , teststepreihenfolge              , max(nr) max_nr            my_table           group              ergebnisnummer              , teststepreihenfolge       ) y       on y.ergebnisnummer = x.ergebnisnummer      , y.teststepreihenfolge = x.teststepreihenfolge     , y.max_nr = x.nr;   +----+----------------+---------------------+----------+  | nr | ergebnisnummer | teststepreihenfolge | messwert |  +----+----------------+---------------------+----------+  |  2 |              1 |                   1 |    86.00 |  |  5 |              1 |                   2 |   304.00 |  |  6 |              1 |                   3 |     0.20 |  |  9 |              2 |                   1 |    80.00 |  | 11 |              2 |                   2 |   301.00 |  | 13 |              2 |                   3 |     0.30 |  +----+----------------+---------------------+----------+

or slower, no subquery...

 select x.*    my_table x    left     join my_table y      on y.ergebnisnummer = x.ergebnisnummer     , y.teststepreihenfolge = x.teststepreihenfolge     , y.nr > x.nr   y.nr null;   +----+----------------+---------------------+----------+   | nr | ergebnisnummer | teststepreihenfolge | messwert |   +----+----------------+---------------------+----------+   |  2 |              1 |                   1 |    86.00 |   |  5 |              1 |                   2 |   304.00 |   |  6 |              1 |                   3 |     0.20 |   |  9 |              2 |                   1 |    80.00 |   | 11 |              2 |                   2 |   301.00 |   | 13 |              2 |                   3 |     0.30 |   +----+----------------+---------------------+----------+

Comments

Post a Comment

Popular posts from this blog

commonjs - How to write a typescript definition file for a node module that exports a function? -

consider, toml node module can use: // toml.d.ts declare module toml { export function parse(value:string):any; } declare module "toml" { export = toml; } then: /// <reference path="../../../../../defs/toml/toml.d.ts"/> import toml = require('toml'); toml.parse(...); however, node module export single function, such 'glob' ( https://github.com/isaacs/node-glob ). the node usage of module be: var glob = require("glob") glob("*.js", {}, callback(err, files) { ... }); you'd naively expect this: // glob.d.ts declare function globs(paths:string, options:any, callback:{(err:any, files:string[]):void; ...but because typescripts 'import' semantics bit strange, seems can use 'import .. = require()' statement alias modules . trying call: /// <reference path="../../../../../defs/glob/glob.d.ts"/> import blog = require('glob'); results in: error ts2072: mod
Read more

openid - Okta: Failed to get authorization code through API call -

i'm integrating okta own idp server using okta's api. i'm implementing authorization code flow following steps below: in own server, use /api/v1/authn endpoint sessiontoken. use sessiontoken obtain authorization calling endpoint: /oauth2/v1/authorize?client_id=" + clientid + "&sessiontoken=" + sessiontoken + "&response_type=code&response_mode=query&scope=openid&redirect_uri=" + redirecturl + "&state=evanyang&nonce=" it's supposed return response status code 302 , location header containing redirect url code value. however, keep getting response status code 200 , without location header, html body saying "you using unsupported browser." , "javascript disabled on browser." according api documentation: http://developer.okta.com/docs/api/resources/oidc.html#authentication-request , sessiontoken parameter sufficient this: an okta one-time sessiontoken. allows api-based
Read more

thorough guide for profiling racket code -

did googling ("racket profiling", "racket measure performance"), didn't find , there no examples in docs. did google "profile" search on htdp - no luck. (profile (f ...)) output isn't obvious other small snippets. ideally want python's python -m cprofile usage examples. when search "python profiling", both duckduckgo , google give top result: 26.4. python profilers . (although scanned quickly, seems more of reference "thorough usage guide" examples. if had else in mind, perhaps please link that?) the equivalent racket documentation be: profile: statistical profiler . a usage example: #lang racket (require profile) (profile-thunk (thunk (function-to-profile arg0 arg1) )) here (thunk e) convenience (lambda () e) . bigger example: #lang racket (module mod racket (provide f) (define (f) (for/list ([i 10000]) i))) (require (prefix-in mod: 'mod)) (define (f) (for ([i 10000
Read more