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MySQLMefuta ea data e tšehetsoeng ke efe?MySQLLintlha tsa mefuta ea data ho
Mefuta ea data ea MySQL
Mefuta ea masimo a data e hlalositsoeng ho MySQL e bohlokoa haholo ho ntlafatseng database ea hau.
MySQL e ts'ehetsa mefuta e fapaneng ea mefuta, e ka aroloang ka mekhahlelo e meraro: mefuta ea linomoro, letsatsi / nako le likhoele (mofuta).
Mofuta oa linomoro
MySQL databaseMefuta eohle e tloaelehileng ea lintlha tsa linomoro tsa SQL lia tšehetsoa.
Mefuta ena e kenyelletsa mefuta e thata ea lintlha tsa linomoro (INTEGER, SMALLINT, DECIMAL, le NUMERIC), le mefuta e hakanyetsoang ea lintlha tsa linomoro (FLOAT, REAL, le DOUBLE PRECISION).
Lentsoe la sehlooho INT ke lentsoe le le leng la INTEGER 'me lentsoe la sehlooho DEC ke lentsoe le tšoanang le la DECIMAL.
Mofuta oa data oa BIT o na le boleng ba tšimo mme o ts'ehetsa litafole tsa MyISAM, MEMORY, InnoDB le BDB.
E le katoloso ea maemo a SQL, MySQL e boetse e ts'ehetsa mefuta e felletseng ea TINYINT, MEDIUMINT, le BIGINT.Tafole e ka tlase e bonts'a sebaka sa polokelo le mefuta e hlokahalang bakeng sa mofuta o mong le o mong o felletseng.
| Mofuta | boholo | sebaka (saennweng) | sebaka (se sa saenneng) | Sebelisa |
|---|---|---|---|---|
| TINYINT | 1 baiti | (-128, 127) | (0, 255) | boleng ba palo e nyane |
| MONYANE | 2 baiti | (-32 768, 32 767) | (0, 65 535) | palo e kholo ea palo |
| MEDIUMINT | 3 baiti | (-8 388 608, 8 388 607) | (0, 16 777 215) | palo e kholo ea palo |
| INT kapa INTEGER | 4 baiti | (-2 147 483 648, 2 147 483 647) | (0, 4 294 967 295) | palo e kholo ea palo |
| MOHOLO | 8 baiti | (-9 233 372 036 854 775 808, 9 223 372 036 854 775 807) | (0, 18 446 744 073 709 551 615) | palo e kholo haholo |
| MOROALLO | 4 baiti | (-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) | nepo e le nngwe boleng ba ntlha e phaphametseng |
| DOUBLE | 8 baiti | (-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, 693 134, 862 315, 7 308, XNUMX XNUMX E-XNUMX) | 0, (2.225 073 858 507 201 4 E-308, 1.797 693 134 862 315 7 E+308) | ho nepahala habeli boleng ba ntlha e phaphametseng |
| QETO | Bakeng sa DECIMAL(M,D), haeba M>D, ke M+2 hape ke D+2 | e ipapisitse le boleng ba M le D | e ipapisitse le boleng ba M le D | boleng ba decimal |
letsatsi le mofuta oa nako
Mefuta ea matsatsi le nako e emelang boleng ba nako ke DATETIME, DATE, TIMESTAMP, TIME, le YEAR.
Mofuta o mong le o mong oa nako o na le mefuta e mengata ea boleng bo nepahetseng le boleng ba "zero", bo sebelisoang ha ho hlakisoa boleng bo fosahetseng boo MySQL e ke keng ea bo emela.
Mofuta oa TIMESTAMP o na le karolo ea hau ea ntlafatso e tla hlalosoa hamorao.
| Mofuta | boholo (baiti) | mefuta | Sebopeho | Sebelisa |
|---|---|---|---|---|
| DATE | 3 | 1000-01-01/9999-12-31 | YYYY-MM-DD | boleng ba letsatsi |
| NAKO | 3 | ‘-838:59:59'/'838:59:59' | HH: MM: SS | boleng ba nako kapa bolelele ba nako |
| SELEMO | 1 | 1901/2155 | ECHA | boleng ba selemo |
| LETSATSI | 8 | 1000-01-01 00:00:00/9999-12-31 23:59:59 | YYYY-MM-DD HH: MM: SS | Maemo a kopaneng a letsatsi le nako |
| NAKO NAKO | 4 | 1970-01-01 00:00:00/2037 年某时 | YYYYMMDDHMMSS | matsatsi a tsoakaneng le nako boleng, timestamp |
Mofuta oa khoele
Mefuta ea likhoele e bua ka CHAR, VARCHAR, BINARY, VARBINARY, BLOB, TEXT, ENUM, le SET.Karolo ena e hlalosa kamoo mefuta ena e sebetsang kateng le mokhoa oa ho e sebelisa lipotsong.
| Mofuta | boholo | Sebelisa |
|---|---|---|
| CHARELA | 0-255 li-byte | khoele e bolelele bo tsitsitseng |
| VARCHAR | 0-65535 li-byte | khoele ea bolelele bo fapaneng |
| TINYBLOB | 0-255 li-byte | binary khoele ea ho fihlela ho 255 litlhaku |
| MONYANE | 0-255 li-byte | khoele ea mongolo o mokgutshwane |
| BOLLO | 0-65 535 li-byte | data e telele ea mongolo ka mokhoa oa binary |
| TEXT | 0-65 535 li-byte | data mongolo o molelele |
| KHABANE LEBAKA | 0-16 777 215 li-byte | Lintlha tsa mongolo oa bolelele bo mahareng ka mokhoa oa binary |
| TS'OANELO TSE KHOLO | 0-16 777 215 li-byte | data ya mongolo wa bolelele bo mahareng |
| LENGOLO | 0-4 294 967 295 li-byte | Lintlha tse kholo haholo tsa mongolo ka mokhoa oa binary |
| TLHOKOMELISO | 0-4 294 967 295 li-byte | data e kgolo haholo ya mongolo |
Mefuta ea CHAR le VARCHAR lia tšoana, empa li bolokoa le ho khutlisoa ka tsela e fapaneng.Li boetse li fapane ho ea ka bolelele ba tsona bo boholo le hore na libaka tsa litsela li bolokiloe.Ha ho phetoho ea nyeoe e etsoang nakong ea polokelo kapa ea ho khutlisa.
Lihlopha tsa BINARY le VARBINARY li tšoana le CHAR le VARCHAR, ntle le hore li na le likhoele tsa binary ho e-na le likhoele tseo e seng tsa binary.Ke hore, li na le likhoele tsa byte ho fapana le likhoele tsa litlhaku.Sena se bolela hore ha ba na sebopeho sa litlhaku, 'me ho hlopha le ho bapisa ho ipapisitse le boleng ba linomoro tsa li-byte tsa boleng ba kholomo.
BLOB ke ntho e kholo ea binary e ka bolokang palo e fapaneng ea data.Ho na le mefuta e 4 ea BLOB: TINYBLOB, BLOB, MEDIUMBLOB le LONGBLOB.Li fapana feela ka bolelele bo boholo ba boleng boo ba ka bo tšoarang.
Ho na le mefuta e 4 ea TEXT: TINYTEXT, TEXT, MEDIUMTEXT le LONGTEXT.Tsena li lumellana le mefuta ea 4 BLOB, e nang le bolelele bo lekanang le litlhoko tsa polokelo.
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