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MySQLKodi mitundu yothandizidwa ndi data ndi iti?MySQLKufotokozera mwatsatanetsatane mitundu ya data mu
Mitundu ya data ya MySQL
Mitundu ya minda ya data yofotokozedwa mu MySQL ndi yofunika kwambiri pakukhathamiritsa kwa database yanu.
MySQL imathandizira mitundu ingapo, yomwe imatha kugawidwa m'magulu atatu: manambala, tsiku / nthawi ndi zingwe (makhalidwe).
Mtundu wa manambala
MySQL databaseMitundu yonse ya data ya SQL yokhazikika imathandizidwa.
Mitundu imeneyi imaphatikizapo mitundu yolimba ya data ya manambala (INTEGER, SMALLINT, DECIMAL, ndi NUMERIC), ndi mitundu pafupifupi ya manambala (FLOAT, REAL, ndi DOUBLE PRECISION).
Mawu osakira INT ndi ofanana ndi INTEGER, ndipo mawu osakira DEC ndi ofanana ndi DECIMAL.
Mtundu wa data wa BIT umasunga magawo ang'onoang'ono ndikuthandizira matebulo a MyISAM, MEMORY, InnoDB ndi BDB.
Monga chowonjezera ku mulingo wa SQL, MySQL imathandiziranso mitundu yonse ya TINYINT, MEDIUMINT ndi BIGINT. Gome lotsatirali likuwonetsa kusungirako ndi kuchuluka komwe kumafunikira pamtundu uliwonse.
| Mtundu | kukula | Range (yosaina) | Range (osasainidwa) | Gwiritsani ntchito |
|---|---|---|---|---|
| TINYINT | 1 bati | (-128) | (0) | mtengo wocheperako |
| WANTHAWI | 2 bati | (-32 768, 32 767) | (0 65) | mtengo wathunthu |
| MEDIUMINT | 3 bati | (-8 388 608, 8 388 607) | (0 16 777) | mtengo wathunthu |
| INT kapena INTEGER | 4 bati | (-2 147 483 648, 2 147 483 647) | (0 4 294 967) | mtengo wathunthu |
| ZABWINO | 8 bati | (-9 233 372 036 854 775 808, 9 223 372 036 854 775 807) | (0 18 446 744 073 709 551) | mtengo wokwanira kwambiri |
| NTHAMBO | 4 bati | (-3.402 823 466 E+38, -1.175 494 351 E-38), 0, (1.175 494 351 E-38, 3.402 823 466 351 E +38) | 0, (1.175 494 351 E-38, 3.402 823 466 E+38) | kulondola kumodzi Mtengo woyandama |
| ZOCHITIKA | 8 bati | (-1.797 693 134 862 | 0, (2.225 073 858 507 201 4 E-308, 1.797 693 134 862 315 7 E+308) | kulondola kawiri Mtengo woyandama |
| KUDZIPEREKA | Kwa DECIMAL(M,D), ngati M>D, ndi M+2 apo ayi ndi D+2 | Zimatengera mayendedwe a M ndi D | Zimatengera mayendedwe a M ndi D | mtengo wa decimal |
Mitundu ya masiku ndi nthawi
Mitundu ya deti ndi nthawi zomwe zikuyimira nthawi ndi DATETIME, DATE, TIMESTAMP, TIME, ndi YEAR.
Mtundu uliwonse wanthawi zonse umakhala ndi zikhalidwe zingapo zovomerezeka komanso mtengo wa "zero", womwe umagwiritsidwa ntchito pofotokoza mtengo wosaloledwa womwe MySQL siyingayimire.
Mtundu wa TIMESTAMP uli ndi zosintha zokha, zomwe zidzafotokozedwe mtsogolo.
| Mtundu | kukula (bayiti) | osiyanasiyana | mtundu | Gwiritsani ntchito |
|---|---|---|---|---|
| DATE | 3 | 1000-01-01/9999-12-31 | YYYY-MM-DD | tsiku mtengo |
| TIME | 3 | ‘-838:59:59'/'838:59:59' | HH: MM: SS | mtengo kapena nthawi |
| YEAKA | 1 | 1901/2155 | YYYY | mtengo wa chaka |
| DETETIME | 8 | 1000-01-01 00:00:00/9999-12-31 23:59:59 | YYYY-MM-DD HH: MM: SS | Sakanizani tsiku ndi nthawi |
| NTHAWI YOCHITIKA | 4 | 1970-01-01 00:00:00/2037 年某时 | YYYYMMDDHMMSS | Zosakaniza za tsiku ndi nthawi, masitampu a nthawi |
mtundu wa chingwe
Mitundu ya zingwe imatchula CHAR, VARCHAR, BINARY, VARBINARY, BLOB, TEXT, ENUM, ndi SET. Gawoli likufotokoza momwe mitunduyi imagwirira ntchito komanso momwe mungagwiritsire ntchito mafunso.
| Mtundu | kukula | Gwiritsani ntchito |
|---|---|---|
| TANKA | 0-255 mabayiti | Chingwe chachitali chokhazikika |
| VARCHAR | 0-65535 mabayiti | kutalika kwa chingwe |
| Mtengo wa TINYBLOB | 0-255 mabayiti | Chingwe cha Binary chosaposa zilembo 255 |
| TINYTEXT | 0-255 mabayiti | chingwe chachifupi cha mawu |
| BUKU | 0-65 535 mabayiti | Zambiri zamalemba zazitali mu mawonekedwe a binary |
| TEXT | 0-65 535 mabayiti | zolemba zazitali zambiri |
| Chithunzi cha MEDIUMBLOB | 0-16 777 215 mabayiti | Zolemba zazitali zazitali mu mawonekedwe a binary |
| MALANGIZO APAKATI | 0-16 777 215 mabayiti | Zolemba zazitali zazitali |
| Zotsatira LONGBLOB | 0-4 294 967 295 mabayiti | Zolemba zazikulu kwambiri zamawonekedwe a binary |
| LONGTEXT | 0-4 294 967 295 mabayiti | Zolemba zazikulu kwambiri |
Mitundu ya CHAR ndi VARCHAR ndizofanana, koma zimasungidwa ndikubwezedwa mosiyana. Amasiyananso malinga ndi kutalika kwake kokwanira komanso ngati malo otsetsereka amasungidwa. Palibe kutembenuka kwamilandu komwe kumachitika panthawi yosungira kapena kubweza.
Makalasi a BINARY ndi VARBINARY ndi ofanana ndi CHAR ndi VARCHAR, kupatula kuti ali ndi zingwe zama binary m'malo mwa zingwe zosagwirizana ndi binary. Ndiko kuti, amakhala ndi zingwe zomangira m'malo mokhala ndi zingwe. Izi zikutanthauza kuti alibe seti ya zilembo, ndipo kusanja ndi kufananitsa kumatengera kuchuluka kwa ma byte amitundu.
BLOB ndi chinthu chachikulu cha binary chomwe chimatha kusunga kuchuluka kwa data. Pali mitundu inayi ya BLOB: TINYBLOB, BLOB, MEDIUMBLOB ndi LONGBLOB. Amangosiyana ndi kutalika kwake komwe angagwire mtengo.
Pali mitundu inayi ya TEXT: TINYTEXT, TEXT, MEDIUMTEXT ndi LONGTEXT. Izi zimagwirizana ndi mitundu 4 ya BLOB, yokhala ndi kutalika kofanana ndi zofunikira zosungira.
Hope Chen Weiliang Blog ( https://www.chenweiliang.com/ ) adagawana "Kodi mitundu ya data yothandizidwa ndi MySQL ndi iti?" Kufotokozera mwatsatanetsatane mitundu ya data mu MySQL" kudzakuthandizani.
Takulandirani kugawana ulalo wa nkhaniyi:https://www.chenweiliang.com/cwl-466.html