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MySQLWaa maxay noocyada xogta la taageeray?MySQLFaahfaahinta noocyada xogta ee
Noocyada xogta MySQL
Noocyada goobaha xogta ee lagu qeexay MySQL ayaa aad muhiim ugu ah hagaajinta xogtaada.
MySQL waxay taageertaa noocyo kala duwan, kuwaas oo qiyaas ahaan loo qaybin karo saddex qaybood: nuucyada, taariikhda/waqtiga, iyo xargaha (dabeecada).
Nooca tirada
database MySQLDhammaan noocyada xogta tirada SQL ee caadiga ah waa la taageeray.
Noocyadan waxaa ka mid ah noocyada xogta nambarada adag (INTEGER, SMALLINT, DECIMAL, iyo NUMERIC), iyo noocyada xogta nambarada qiyaas ahaan (FLOAT, REAL, iyo DOUBLE PRECISION).
Erayga muhiimka ah ee INT waxa uu la mid yahay INTEGER iyo erayga muhiimka ah ee DEC waxa uu la mid yahay DECIMAL.
Nooca xogta BIT waxa ay haysaa qiyamka goobta yar waxayna taageertaa MyISAM, MEMORY, InnoDB, iyo miisaska BDB.
Sida kordhinta heerka SQL, MySQL sidoo kale waxay taageertaa noocyada isku-darka TINYINT, MEDIUMINT, iyo BIGINT.Jadwalka hoose waxa uu tusinayaa kaydinta iyo kala duwanaanta looga baahan yahay nooc kasta oo tirooyin ah.
| 类型 | cabir | kala duwan (saxiixan) | kala duwan (aan saxeexin) | Adeegso |
|---|---|---|---|---|
| TININT | 1 byte | (-128, 127) | (0, 255) | qiimaha tiro yar |
| YAR YAR | 2 byte | (-32 768, 32 767) | (0, 65 535) | qiimaha isugeynta weyn |
| DHEXDHEXAAD | 3 byte | (-8 388 608, 8 388 607) | (0, 16 777 215) | qiimaha isugeynta weyn |
| INT ama INTEGER | 4 byte | (-2 147 483 648, 2 147 483 647) | (0, 4 294 967 295) | qiimaha isugeynta weyn |
| WEYN | 8 byte | (-9 233 372 036 854 775 808, 9 223 372 036 854 775 807) | (0, 18 446 744 073 709 551 615) | qiimaha isugeynta aad u weyn |
| WADAAD | 4 byte | (-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) | saxda ah hal qiimaha barta sabayn |
| labo | 8 byte | (-1.797 693 134 862 315 7 E+308, -2.225 073 858 507 201 4 E-308), 0, (2.225 073 858 507 201 4 E-308, 1.797) | 0, (2.225 073 858 507 201 4 E-308, 1.797 693 134 862 315 7 E+308) | labanlaab sax ah qiimaha barta sabayn |
| GO'AAN | DECIMAL(M,D), haddii M>D, waa M+2 kale waa D+2 | waxay ku xiran tahay qiimaha M iyo D | waxay ku xiran tahay qiimaha M iyo D | qiimaha tobanle |
taariikhda iyo nooca waqtiga
Noocyada taariikhda iyo wakhtiga ee metelaya qiyamka wakhtiga waa DATETIME, DATE, TIMESTAMP, TIME, iyo YEAR.
Nooc kastaa wuxuu leeyahay qiimeyaal kala duwan oo ansax ah iyo "eber", kaas oo la isticmaalo marka la tilmaamayo qiime aan sax ahayn oo MySQL uusan matali karin.
Nooca TIMESTAMP waxa uu leeyahay sifo dib-u-cusbooneysiin oo iskeed u gaar ah oo hadhow lagu sifayn doono.
| 类型 | cabir (byte) | kala duwan | qaab | Adeegso |
|---|---|---|---|---|
| DATE | 3 | 1000-01-01/9999-12-31 | YYYY-MM-DD | qiimaha taariikhda |
| TIME | 3 | ‘-838:59:59'/'838:59:59' | HH: MM: SS | qiimaha waqtiga ama muddada |
| YEAR | 1 | 1901/2155 | SSSS | qiimaha sanadka |
| WAQTIGA | 8 | 1000-01-01 00:00:00/9999-12-31 23:59:59 | YYYY-MM-DD HH: MM: SS | Qiimaha taariikhda iyo wakhtiga isku dhafan |
| WAQTIGA | 4 | 1970-01-01 00:00:00/2037 年某时 | YYYYMMDDHHMMSS | qiimaha taariikhda iyo wakhtiga isku dhafan, timestamp |
Nooca xargaha
Noocyada xargaha waxay tixraacaan CHAR, VARCHAR, BINARY, VARBINARY, BLOB, TEXT, ENUM, iyo SET.Qaybtani waxa ay sharraxaysaa sida noocyadani u shaqeeyaan iyo sida loogu isticmaalo su'aalaha.
| 类型 | cabir | Adeegso |
|---|---|---|
| SHARCIGA | 0-255 bytes | xadhig go'an |
| VARCAR | 0-65535 bytes | xadhig dhererka variable |
| TINYBLOB | 0-255 bytes | Xadhig binary ah oo gaaraya ilaa 255 xaraf |
| TINYTEXT | 0-255 bytes | xadhig qoraal gaaban |
| XADGUDUB | 0-65 535 bytes | xogta qoraalka dheer ee qaabka binary |
| TEXT | 0-65 535 bytes | xogta qoraalka dheer |
| BLOB DHEXE | 0-16 777 215 bytes | Xogta qoraalka dhererka dhexdhexaadka ah ee qaabka laba-geesoodka ah |
| DHEXDHEXAADTEXT | 0-16 777 215 bytes | xogta qoraalka dhererka dhexdhexaadka ah |
| LONGBLOB | 0-4 294 967 295 bytes | Xog qoraal ah oo aad u weyn oo qaab laba-geesood ah |
| LONGTEXT | 0-4 294 967 295 bytes | xogta qoraalka aad u weyn |
Noocyada CHAR iyo VARCHAR waa isku mid, laakiin si kala duwan ayaa loo kaydiyaa oo loo soo ceshado.Waxay kaloo ku kala duwan yihiin dhererkooda ugu badan iyo haddii meelaha daba-galka ah la ilaaliyo.Ma jiro beddel kiis oo la sameeyo inta lagu jiro kaydinta ama soo celinta.
Fasallada BINARY iyo VARBINARY waxay la mid yihiin CHAR iyo VARCHAR, marka laga reebo inay ka kooban yihiin xargaha binary halkii ay ka ahaan lahaayeen xargaha aan binary-ga ahayn.Taasi waa, waxay ka kooban yihiin xargaha byte halkii ay ka ahaan lahaayeen xargaha xargaha.Tani waxay ka dhigan tahay inaysan lahayn dabeecad dejin, kala-soocidda iyo isbarbardhigga waxay ku saleysan tahay qiyamka tirada ee byteska qiimaha tiirka.
BLOB waa shay weyn oo laba-jibaaran ah oo hayn kara xog badan oo isbedbedesha.Waxaa jira 4 nooc oo BLOB ah: TINYBLOB, BLOB, MEDIUMBLOB iyo LONGBLOB.Kaliya waxay ku kala duwan yihiin dhererka ugu sarreeya ee qiimaha ay hayn karaan.
Waxaa jira 4 nooc oo qoraal ah: TINYTEXT, TEXT, MEDIUMTEXT iyo LONGTEXT.Kuwani waxay u dhigmaan noocyada 4 BLOB, oo leh dherer isku mid ah iyo shuruudaha kaydinta.
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