Izinhlobo eziyinhloko zedatha ye-Mysql

Kulabo abangazi ukuthi i-Mysql yimuphi, sibika ukuthi lena yindlela ephumelela kakhulu ongayiphatha ngayo idatha enkulu. Kumahhala futhi unikezwa kubasebenzisi ngaphansi kwelayisense jikelele. Ekuqaleni kokuthuthukiswa kobuchwepheshe bekhompyutha, ulwazi "lwalondolozwe" emafayeleni ahlukene, bese lukhishwa kubo njengokudinga. Namuhla izinhlelo ezinjalo azihlali zisebenza njalo, ngoba Kuthatha isikhathi esiningi nomzamo. Uhlelo lwe-Mysql likuvumela ukuba uhlele ulwazi futhi wenze imisebenzi kumathuluzi wedatha usebenzisa ikhodi yomyalo ohlangene kakhulu.

Ukuze i -database isebenze kahle, i-Mysql inomqondo wohlobo lwedatha. Kunezinketho eziningana zedatha:

- I-VAR (n) noma i-VARCHAR (n) - umlingisi, lapho n inombolo yezinyathelo ezingasetshenziswa (VARCHAR izitolo ezingekho kuka-255 izinhlamvu);

- izinhlobo zezintambo zezintambo ze-mysql, kufaka phakathi amafomethi alandelayo: TEXT (n) - lapho n ingafinyelela ku-65535, TINITEXT (n) - lapho n ingaba khona ku-255, MEDIUMTEXT (n) kusuka ku-n 77 kuya ku-16 777 215 ne-LONGTEXT ( N) eguquguqukayo n, engafinyelela ku-4,294,967,295 (kusuka ku-VARCHAR i-TEXT ehlukahluka kulokho ku-TEXT (n) izinhlamvu zokuqala zikhokhelwe);

- VARBINARY noma BINARY - ukugcina izithombe kukhodi kanambambili ;

- I-Mysql BLOB (n) izinhlobo zedatha ezinesimo esifanayo nama-prefixes njenge-TEXT (TINY-, MEDIUM-, LONGBLOB) sebenzisa izinhlobo zeDatha ye-Mysql BLOB (n) zokugcina izinto ezinkulu zobunambambili necala labalingiswa; Isibonelo, i-MEDIUMBLOB (n) inezinga elilingana no-16 777 215;

- izinhlobo zedatha isikhathi nosuku, kufaka phakathi: DATE - idethi yenyanga yenyanga, i-TIME - isikhathi ngehora lesigamu sesigamu sehora, iminyaka engu-YEAR kusukela ngo-1901 kuya ku-2155 nonyaka we-0000, i-DATETIME - ihlanganisa u-DATE futhi I-TIME (uhlobo lokugcina lwedatha lukhishwa kwifomethi yenyanga-yehora-ngomzuzu-wesibili); Futhi, kunezinhlobo zedatha yefomethi ye-Mysql TIMESTAMP, evumela ukuthi wenze iminyaka yedatha kusukela ngo-1970 kuya ku-2037 (lokhu kungenxa yokucabanga kwabadali behlelo ukuthi i-Mysql igcina isiphelile ngo-2037);

- izinombolo, ezakhiweni zayo ezinamanani aphelele we-data, kufaka phakathi i-INT - inamba kusuka ku-2.1 billion kuya kwezingu-2.1 billion, i-TINYINT - inombolo kusuka ku-128 kuya ku -127 noma kusuka ku-255 kuya ku-0, i-SMALINT - kusuka ku-76 768 kuya ku-32 767, i-BIGINT - kusuka ku-9 x 10 ngezinga leshumi nesishiyagalombili kuya ku -9 x 10 ngezinga leshumi nesishiyagalombili, MEDIUMINT - kusuka ku-8.388 million ukuya ku -8.388 million (uma ngabe olunye uhlobo lwedatha lubeka inombolo enkulu kunaleyo Isilinganiso esiphezulu sesethi, sizobe sithathwe ngamanani anamukelekayo).

Futhi kunezinhlobo zezinombolo ezingxenyeni ezithile - I-FLOAT iyinombolo ye-floating-point, i-DOUBLE ne-REAL yinombolo yobukhulu obuphindwe kabili ngephuzu elintantayo, i-NUMERIC ne-DECIMAL yinombolo encane egciniwe njengezintambo. Kuhlelo, ikakhulukazi i-FLOAT ne-INT isetshenzisiwe, esekela isivinini esiphezulu se-database.

Ukusebenza ngolwazi olwenziwe ngethuluzi le-PHPMyAdmin, elinikezwa mahhala ku-Denver iphakheji. Ukusebenzisa, ungakha idatha ngokucacisa amagama e-database kanye namatafula ahlukahlukene, izinhlobo zedatha, amaphasiwedi. Emva kwalokho i-database igcwele ulwazi, ungadala imibuzo ngendlela yokusesha (khetha), shintsha (Shintsha, RENAME, MODIFY), susa (Sula), engeza (ADD) noma uhlele idatha etholakalayo bese ubonisa imingcele ethile esibukweni. Izinhlobo zedatha ye-Mysql kuleli cala kufanele zengezwe ngokucophelela ukuze izinhlelo zingenzi amaphutha. Isibonelo, ungacacisa uhlobo lwemininingwane ye-VARCHAR, evumela ukuthi ukufaka umbhalo kube ngaphezu kwezinhlamvu ezingu-255. Futhi uma i-database isigcwele, umbhalo uzoba mkhulu, okuzokwenza i-Mysql "iqede" umbhalo kumkhawulo owamukelekayo.