{"id":190,"date":"2022-08-30T12:29:03","date_gmt":"2022-08-30T12:29:03","guid":{"rendered":"https:\/\/informatika.tbg.hu\/?page_id=190"},"modified":"2022-08-30T12:29:03","modified_gmt":"2022-08-30T12:29:03","slug":"sql-nem-valaszto-lekerdezesek","status":"publish","type":"page","link":"https:\/\/informatika.tbg.hu\/index.php\/sql-nem-valaszto-lekerdezesek\/","title":{"rendered":"SQL \u2013 nem v\u00e1laszt\u00f3 lek\u00e9rdez\u00e9sek"},"content":{"rendered":"\n

Friss\u00edt\u0151 (adatm\u00f3dos\u00edt\u00f3) lek\u00e9rdez\u00e9s<\/h2>\n\n\n\n

A parancsunk az UPDATE<\/strong>.<\/p>\n\n\n\n

UPDATE<\/strong> t\u00e1blan\u00e9v SET<\/strong> mez\u01511=\u00e9rt\u00e9k1, mez\u01512=\u00e9rt\u00e9k2 [WHERE<\/strong> felt\u00e9tel]<\/p>\n\n\n\n

A t\u00e1blan\u00e9v a t\u00e1bl\u00e1n neve, \u00e9s a SET parancs ut\u00e1n felsoroljuk, milyen mez\u0151[k]nek kell megv\u00e1ltozni[uk]. A legt\u00f6bb esetben nem mindegyiknek, \u00edgy a WHERE paranccsal sz\u0171rhetj\u00fck a rekordokat. P\u00e9lda lent.<\/p>\n\n\n\n

Adatok beilleszt\u00e9se<\/h2>\n\n\n\n

A parancsunk az INSERT<\/strong><\/p>\n\n\n\n

INSERT INTO<\/strong> t\u00e1blan\u00e9v(mez\u01511, mez\u01512, \u2026.) VALUES<\/strong> (\u00e9rt\u00e9k1, \u00e9rt\u00e9k2, \u2026)<\/p>\n\n\n\n

A t\u00e1blan\u00e9v ut\u00e1n meg kell adnunk, hogy milyen mez\u0151kbe, a VALUES ut\u00e1n, hogy RENDRE milyen \u00e9rt\u00e9keke ker\u00fcljenek. \u00dcgyelni kell a sorrendre, az \u00e9rt\u00e9kek olyan sorrendbe \u00e9rkezzenek, amiben a t\u00e1blan\u00e9v ut\u00e1n meghat\u00e1roztuk!<\/p>\n\n\n\n

Rekordok t\u00f6rl\u00e9se<\/h2>\n\n\n\n

A parancs a DELETE<\/strong><\/p>\n\n\n\n

DELETE FROM<\/strong> t\u00e1blan\u00e9v [WHERE<\/strong> felt\u00e9tel]<\/p>\n\n\n\n

A WHERE felt\u00e9tel-t [ ] k\u00f6zz\u00e9 \u00edrtam, teh\u00e1t nem k\u00f6telez\u0151, de vigy\u00e1zzunk, mert ha elmarad, minden rekordot t\u00f6rl\u00fcnk a t\u00e1bl\u00e1b\u00f3l!<\/p>\n\n\n\n

P\u00e9lda:<\/p>\n\n\n\n

Adott egy tanulok nev\u0171 adatt\u00e1bla:<\/p>\n\n\n\n

tanulok<\/strong><\/td><\/tr>
ID<\/th>NEV<\/th>EVFOLYAM<\/th>OSZTALY<\/th>ATLAG<\/th><\/tr>
1<\/td>Kis B\u00e9la<\/td>10<\/td>A<\/td>4,5<\/td><\/tr>
2<\/td>Kis Bogl\u00e1rka<\/td>10<\/td>B<\/td>3,89<\/td><\/tr>
3<\/td>Aranyos Alad\u00e1r<\/td>9<\/td>A<\/td>3,48<\/td><\/tr>
4<\/td>Zsupp\u00e1n Aranka<\/td>10<\/td>A<\/td>5<\/td><\/tr>
5<\/td>Neholovics B\u00e9la<\/td>9<\/td>A<\/td>2,89<\/td><\/tr>
6<\/td>Turi Zs\u00f3fia<\/td>10<\/td>B<\/td>4,29<\/td><\/tr>
7<\/td>Ger\u0151 Imola<\/td>10<\/td>A<\/td>5<\/td><\/tr>
8<\/td>Barab\u00e1s Imre<\/td>9<\/td>B<\/td>4,11<\/td><\/tr>
9<\/td>Kiss Lajos<\/td>10<\/td>B<\/td>3,12<\/td><\/tr>
10<\/td>Nagy Lajos<\/td>10<\/td>B<\/td>3,40<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
  1. A 3-as ID-vel rendelkez\u0151 tanul\u00f3nak az \u00e9vfolyama t\u00e9ves! Jav\u00edtsuk 10-re
    UPDATE tanulok SET evfolyam=10 WHERE ID=3__________________________________<\/li>
  2. K\u0151m\u00edves Kelemen 9.B oszt\u00e1lyos tanul\u00f3, kinek az \u00e1tlaga 4,77 hi\u00e1nyzik. P\u00f3toljuk!
    INSERT INTO tanulok(nev,evfolyam,osztaly,atlag) VALUES (\u201eK\u0151m\u00edves Kelemen\u201d,9,\u201dB\u201d,4,77)__
    Megjegyz\u00e9s: Az ID mez\u0151 egy Sz\u00e1ml\u00e1l\u00f3 t\u00edpus\u00fa \u00e9rt\u00e9k, automatikan kap \u00e9rt\u00e9ket, ez\u00e9rt nem szerepelt)<\/em><\/li>
  3. T\u00f6r\u00f6lj\u00fck Kiss Lajos 10.B oszt\u00e1lyos tanul\u00f3t a t\u00e1bl\u00e1b\u00f3l!
    DELETE FROM tanulok WHERE nev=\u201dKiss Lajos\u201d AND evfolyam=10 AND osztaly=\u201dB\u201d________<\/li><\/ol>\n","protected":false},"excerpt":{"rendered":"

    Friss\u00edt\u0151 (adatm\u00f3dos\u00edt\u00f3) lek\u00e9rdez\u00e9s A parancsunk az UPDATE. UPDATE t\u00e1blan\u00e9v SET mez\u01511=\u00e9rt\u00e9k1, mez\u01512=\u00e9rt\u00e9k2 [WHERE felt\u00e9tel] A t\u00e1blan\u00e9v a t\u00e1bl\u00e1n neve, \u00e9s a SET parancs ut\u00e1n felsoroljuk, milyen mez\u0151[k]nek kell megv\u00e1ltozni[uk]. A legt\u00f6bb esetben nem mindegyiknek, \u00edgy a WHERE paranccsal sz\u0171rhetj\u00fck a rekordokat. P\u00e9lda lent. Adatok beilleszt\u00e9se A parancsunk az INSERT INSERT INTO t\u00e1blan\u00e9v(mez\u01511, mez\u01512, \u2026.) VALUES (\u00e9rt\u00e9k1, \u00e9rt\u00e9k2, \u2026) A t\u00e1blan\u00e9v ut\u00e1n meg kell adnunk, […]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-190","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/informatika.tbg.hu\/index.php\/wp-json\/wp\/v2\/pages\/190","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/informatika.tbg.hu\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/informatika.tbg.hu\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/informatika.tbg.hu\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/informatika.tbg.hu\/index.php\/wp-json\/wp\/v2\/comments?post=190"}],"version-history":[{"count":1,"href":"https:\/\/informatika.tbg.hu\/index.php\/wp-json\/wp\/v2\/pages\/190\/revisions"}],"predecessor-version":[{"id":191,"href":"https:\/\/informatika.tbg.hu\/index.php\/wp-json\/wp\/v2\/pages\/190\/revisions\/191"}],"wp:attachment":[{"href":"https:\/\/informatika.tbg.hu\/index.php\/wp-json\/wp\/v2\/media?parent=190"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}