Yadda ake share bayanai daga tebur ta amfani da DELETE
sanarwa a cikin SQL
Amsa: Yi amfani da DELETE
bayanin don cire bayanai daga tebur
Misali:
Bayyana manufar wani Index
da fa'idodin amfani da Fihirisa a cikin SQL
Amsa: An Index
shine tsarin bayanan da ke inganta saurin dawo da bayanai a cikin ma'ajin bayanai. An ƙirƙira shi akan ɗaya ko fiye da ginshiƙan tebur kuma yana taimakawa wajen rage lokacin da ake buƙata don nema da rarraba bayanai. Fa'idodin amfani da Fihirisar sun haɗa da ingantattun aikin tambaya da maido da bayanai cikin sauri.
Yadda ake amfani da CREATE TABLE
bayanin don ƙirƙirar sabon tebur a cikin SQL
Amsa: Yi amfani da CREATE TABLE
bayanin don ƙirƙirar sabon tebur a cikin bayanan.
Misali:
Yadda ake amfani da ALTER TABLE
bayanin don ƙara sabon shafi zuwa tebur a cikin SQL.
Amsa: Yi amfani da ALTER TABLE
bayanin don ƙara sabon shafi zuwa tebur mai gudana.
Misali:
Yadda ake amfani da DROP TABLE
bayanin don share tebur a cikin SQL
Amsa: Yi amfani da DROP TABLE
bayanin don cire tebur daga ma'ajin bayanai.
Misali:
Bayyana yadda ake amfani da bayanan UNION
da UNION ALL
maganganun a cikin SQL
Amsa:
UNION
: Yana haɗa sakamakonSELECT
tambayoyi biyu ko fiye zuwa saitin sakamako ɗaya kuma yana cire kwafi.UNION ALL:
Kama daUNION
, amma yana riƙe da kwafin layuka.
Yadda ake amfani da LIKE
bayanin da haruffa na musamman a cikin yanayin bincike a cikin SQL
Amsa: Yi amfani da bayanin LIKE don yin daidaitaccen tsari don binciken rubutu. Akwai haruffa na musamman guda biyu da aka saba amfani da su tare da LIKE
:
- %: Yana wakiltar kowane jeri na haruffa, gami da sifili ko fiye da haruffa.
- _: Yana wakiltar hali guda ɗaya.
Yi bayani daban-daban tambayoyin dawo da bayanai: SELECT, SELECT DISTINCT, SELECT TOP
a cikin SQL
Amsa:
SELECT
: Maido bayanai daga tebur ɗaya ko fiye.SELECT DISTINCT
: Yana dawo da keɓaɓɓun bayanai daga ginshiƙi, yana cire ƙima mai kwafi.SELECT TOP
: Yana dawo da takamaiman adadin layuka daga sakamakon tambaya.
Yadda ake amfani da GROUP BY, HAVING, ORDER BY
maganganun tare a cikin SQL
Amsa: Ta hanyar haɗa GROUP BY, HAVING, ORDER BY
bayanan, za mu iya tattara bayanai, tace ƙungiyoyi, da tsara sakamakon.
Misali:
Bayyana manufar a transaction
da kuma yadda ake amfani da BEGIN TRANSACTION, COMMIT, ROLLBACK
maganganun a cikin SQL.
Amsa: Ma'amala shine jerin ayyuka guda ɗaya ko fiye da ake kula da su azaman raka'a ɗaya. Idan kowane ɗayan ayyukan da ke cikin ma'amala ya gaza, gabaɗayan ma'amalar za ta koma baya kuma duk canje-canjen an soke su.
BEGIN TRANSACTION
: Fara sabon ciniki.COMMIT
: Ajiye da kuma tabbatar da canje-canjen da aka yi a cikin ma'amala zuwa bayanan bayanai.ROLLBACK
: Yana soke ciniki kuma yana soke duk wani canje-canje da aka yi a cikin ciniki