{"id":30,"date":"2011-09-26T10:53:43","date_gmt":"2011-09-26T10:53:43","guid":{"rendered":"http:\/\/sql.programisius.lt\/?page_id=30"},"modified":"2011-09-27T12:22:08","modified_gmt":"2011-09-27T12:22:08","slug":"3-duomenu-isinkimas","status":"publish","type":"page","link":"http:\/\/sql.programisius.lt\/?page_id=30","title":{"rendered":"3. Duomen\u0173 i\u0161rinkimas"},"content":{"rendered":"

SELECT u\u017eklausa yra skirta u\u017eklausti duomen\u0173 baz\u0117s ir gauti pasirinktus duomenis, kurie atitinka i\u0161keltus reikalavimus. U\u017eklausos formatas yra:<\/p>\n

\n
SELECT \" stulpelis1\" \u00a0 [,\"stulpelis2\", t.t.] \r\nFROM \"lenetl\u0117svardas\" \u00a0 [WHERE \"s\u0105lygos\"]; <\/code><\/span><\/pre>\n
[] - nurodo, kad pasirenkamas <\/code><\/span><\/pre>\n<\/blockquote>\n
Stulpelio vardai, kurie nurodyti po SELECT, apibr\u0117\u017eia kuri\u0173 stulpeli\u0173 duomenys turi b\u016bti rezultate. Galime pasirinkti tiek stulpeli\u0173 kiek tik pageidaujame ir netgi jei mus domina visi stulpeliai, tai su \u201e*\u201c galima u\u017esakyti visus.<\/p>\n
Lentel\u0117s vardas nurodomas po raktinio \u017eod\u017eio FROM, kas rei\u0161kia, kad duomenys bus formuojami i\u0161 tos lentel\u0117s.<\/p>\n
Raktinis \u017eodis WHERE n\u0117ra b\u016btinas, bet jis nurodo s\u0105lygas, kurias turi atitikti eilut\u0117s pagal stulpeli. S\u0105lygos po WHERE gali b\u016bti:<\/p>\n
=<\/span> lygu
\n><\/span> daugiau negu
\n<<\/span> ma\u017eiau negu
\n>=<\/span> daugiau negu arba lygu
\n<=<\/span> ma\u017eiau negu arba lygu
\n<><\/span> nelygu
\nLIKE\u00a0<\/span> \u0161ablono operatorius, kuris nurodo simbolin\u0117s eilut\u0117s pana\u0161umo savybes. \u0160is operatorius rei\u0161kia, kad tekstas turi b\u016bti pana\u0161us \u012f nurodyt\u0105. Procentas % nurodo, kad gali b\u016bti bet kokie simboliai, o tuo tarpu kiti simboliai yra privalomi analizuojame\u00a0 duomenyje.<\/p>\n
Lentel\u0117 darbuotojai.<\/p>\n\n\n\n\n\n\n\n\n\n
\n
vardas<\/strong><\/p>\n<\/td>\n
\n
pavarde<\/strong><\/p>\n<\/td>\n
\n
nr<\/strong><\/p>\n<\/td>\n
\n
amzius<\/strong><\/p>\n<\/td>\n
\n
miestas<\/strong><\/p>\n<\/td>\n
\n
apskritis<\/strong><\/p>\n<\/td>\n<\/tr>\n
Vardis<\/td>\nPavardis<\/td>\n99980<\/td>\n45<\/td>\nVilnius<\/td>\nVilniaus<\/td>\n<\/tr>\n
Jonas<\/td>\nJonaitis<\/td>\n99981<\/td>\n34<\/td>\nKaunas<\/td>\nKauno<\/td>\n<\/tr>\n
Petras<\/td>\nPetraitis<\/td>\n99982<\/td>\n65<\/td>\n\u0160iauliai<\/td>\n\u0160iauli\u0173<\/td>\n<\/tr>\n
Vytautas<\/td>\nDidysis<\/td>\n99983<\/td>\n33<\/td>\nTrakai<\/td>\nVilniaus<\/td>\n<\/tr>\n
Birut\u0117<\/td>\nJonien\u0117<\/td>\n99984<\/td>\n23<\/td>\nMa\u017eeikiai<\/td>\nTel\u0161i\u0173<\/td>\n<\/tr>\n
Ona<\/td>\nPetrait\u0117<\/td>\n99984<\/td>\n27<\/td>\nPalanga<\/td>\nKlaip\u0117dos<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
SELECT vardas, pavarde, miestas<\/span>
\n\u00a0\u00a0 FROM\u00a0darbuotojai<\/span>
\n\u00a0\u00a0 WHERE pavarde LIKE ‘Jon%’;<\/span><\/p>\n
Rezultatas<\/p>\n\n\n\n\n\n
\n
vardas<\/strong><\/p>\n<\/td>\n
\n
pavarde<\/strong><\/p>\n<\/td>\n
\n
miestas<\/strong><\/p>\n<\/td>\n<\/tr>\n
Jonas<\/td>\nJonaitis<\/td>\nKaunas<\/td>\n<\/tr>\n
Birut\u0117<\/td>\nJonien\u0117<\/td>\nMa\u017eeikiai<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\u012eveskite kitus pavyzdines SELECT u\u017eklausas, kurios pateiktos \u017eemiau. Palyginkite k\u0105 jos duoda, kuo jos skiriasi.<\/p>\n
select vardas, pavarde, miestas from darbuotojai;\u00a0<\/span><\/p>\n
select vardas, pavarde, miestas from darbuotojai<\/span>
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 where amzius > 30;<\/span><\/p>\n
\u00a0select vardas, pavarde, miestas from darbuotojai<\/span>
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 where vardas LIKE ‘J%’;<\/span><\/p>\n
\u00a0select * from darbuotojai;<\/span><\/p>\n
\u00a0select vardas, pavarde from darbuotojai<\/span>
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 where pavarde LIKE ‘%s’;<\/span><\/p>\n
\u00a0select vardas, pavarde, amzius from darbuotojai<\/span>
\n\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 where pavarde LIKE ‘%ait%’;<\/span><\/p>\n
\u00a0select * from darbuotojai where vardas \u00a0= ‘Ona’;<\/span><\/p>\n
\u00a0<\/span>SELECT u\u017eklausos u\u017edaviniai:<\/p>\n
 <\/p>\n
1. Pateikti vis\u0173 lentel\u0117je esan\u010di\u0173j\u0173 tik vard\u0105 ir am\u017ei\u0173.
\n2. Pateikti vis\u0173 vardus, pavardes ir miestus, kurie yra i\u0161 Vilniaus apskrities.
\n3. Pateikti vis\u0105 informacij\u0105 apie tuos, kurie vyresni nei 30 met\u0173.
\n4. Gauti vardus ir pavardes t\u0173, kuri\u0173 pavard\u0117 baigiasi gal\u016bne \u201eis\u201c.
\n5. Gauti vis\u0105 informacij\u0105, kuri\u0173 pavard\u0117 turi jungin\u012f \u201eon\u201c.<\/p>\n
 <\/p>\n","protected":false},"excerpt":{"rendered":"
SELECT u\u017eklausa yra skirta u\u017eklausti duomen\u0173 baz\u0117s ir gauti pasirinktus duomenis, kurie atitinka i\u0161keltus reikalavimus. U\u017eklausos formatas yra: SELECT ” stulpelis1″ \u00a0 [,”stulpelis2″, t.t.] FROM “lenetl\u0117svardas” \u00a0 [WHERE “s\u0105lygos”]; [] – nurodo, kad pasirenkamas Stulpelio vardai, kurie nurodyti po SELECT, apibr\u0117\u017eia kuri\u0173 stulpeli\u0173 duomenys turi b\u016bti rezultate. Galime pasirinkti tiek stulpeli\u0173 kiek tik pageidaujame ir […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2,"menu_order":3,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-30","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"http:\/\/sql.programisius.lt\/index.php?rest_route=\/wp\/v2\/pages\/30","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/sql.programisius.lt\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/sql.programisius.lt\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/sql.programisius.lt\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/sql.programisius.lt\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=30"}],"version-history":[{"count":11,"href":"http:\/\/sql.programisius.lt\/index.php?rest_route=\/wp\/v2\/pages\/30\/revisions"}],"predecessor-version":[{"id":194,"href":"http:\/\/sql.programisius.lt\/index.php?rest_route=\/wp\/v2\/pages\/30\/revisions\/194"}],"up":[{"embeddable":true,"href":"http:\/\/sql.programisius.lt\/index.php?rest_route=\/wp\/v2\/pages\/2"}],"wp:attachment":[{"href":"http:\/\/sql.programisius.lt\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=30"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}