MySQL e theha tatellano joang? Polelo ea tatelano ea tatellano ea tatellano ea database ea MySQL

MySQLJoang ho theha tatellano?MySQL databaseTheha polelo ea tatelano e iketselitseng

Tšebeliso ea tatellano ea MySQL

Tatelano ea MySQL ke sete sa lipalo-palo: 1, 2, 3, ..., kaha tafole ea data e ka ba le senotlolo se le seng sa mantlha sa "auto-increment", haeba u batla ho fihlela increment ea likarolo tse ling, u ka sebelisa tatellano ea MySQL ho finyella.

Khaolong ena re tla hlalosa mokhoa oa ho sebelisa tatellano ea MySQL.


Sebelisa AUTO_INCREMENT

Mokhoa o bonolo oa ho sebelisa tatellano ho MySQL ke ho sebelisa MySQL AUTO_INCREMENT ho hlalosa likholomo.

Mohlala

Lethathamo la data Sekokoanyana se entsoe ka mohlala o latelang, moo ho se nang boleng bo boletsoeng bakeng sa kholo ea boiketsetso.

mysql > CREATE TABLE昆虫
     - > - > id INT UNSIGNED NOT NULL AUTO_INCREMENT - > PRIMARY KEY id ),- > name VARCHAR 30 NOT NULL #昆虫类型- > 日期DATE NOT NULL #收集日期- > origin VARCHAR 30 NOT NULL #where collected ); 查询OK 0 行受影响0.02 
mysql > 
    
    
     
     
    

 INSERT INTO insects id name date origin VALUES
     - > NULL 'housefly' '2001-09-10' 'kitchen' ),- > NULL 'millipede' '2001-09-10 ' '车道' ),- > NULL 'grasshopper' '2001-09-10' 'front yard' ); 查询OK  
     
     
 记录3 重复0 警告0 
mysql > 选择* 从昆虫ORDER BY ID ; + ---- + ------------- + ------------ + ------------ + | id | 名字         | 日期        | 起源      | + ---- + ------------- + ------------ + ------------ + | 1 | 家蝇     | 2001 - 09 - 10 | 厨房     | | 2 | 千足虫   
       



     
   | 2001 - 09 - 10 | 车道    | | 3 | 蚱蜢| 2001 - 09 - 10 | 前院| + ---- + ------------- + ------------ + ------------ + 3 0.00   
     

  

Fumana boleng ba AUTO_INCREMENT

Ho moreki oa MySQL o ka sebelisa LAST_INSERT_ID() ts'ebetso ho SQL ho fumana boleng ba kholomo ea ho qetela ea auto-incremented e kentsoeng tafoleng.

Mesebetsi e tsamaellanang e boetse e fanoe ho PHP kapa PERL script ho fumana boleng ba kholomo ea ho qetela ea "auto-increment" e kentsoeng tafoleng.

Mohlala oa PERL

Sebelisa thepa ea mysql_insertid ho fumana boleng ba AUTO_INCREMENT.Mehlala ke e latelang:

$ dbh - > do “INSERT INTO insect(name,date,origin) 
VALUES('moth','2001-09-14','windowsill')“ ); my $ seq = $ dbh - > { mysql_insertid };

PHP mohlala

PHP e fumana boleng ba kholomo ea AUTO_INCREMENT polelong e kentsoeng ea SQL ka ts'ebetso ea mysql_insert_id().

mysql_query “INSERT INTO昆虫(名字,日期,起源)
VALUES('moth','2001-09-14','windowsill')“ $ conn_id ); 
$ seq = mysql_insert_id $ conn_id );

tsosolosa tatelano

Haeba u hlakola lirekoto tse ngata tafoleng ea data 'me u batla ho hlophisa bocha kholomo ea AUTO_INCREMENT ea data e setseng, u ka etsa joalo ka ho hlakola kholomo e ikatisang ebe u e eketsa hape.Leha ho le joalo, ts'ebetso ena e tlameha ho ba hlokolosi haholo, haeba ho hang.Ka nako e ts'oanang ea ho hlakoloa, lirekoto tse ncha lia eketsoa, ​​​​mme ho ka ba le pherekano ea data. Ts'ebetso e tjena:

mysql > ALTER TABLE昆虫DROP ID ; 
mysql > ALTER TABLE昆虫
     - > ADD ID INT UNSIGNED NOT NULL AUTO_INCREMENT FIRST - > ADD PRIMARY KEY id );
    

Beha boleng ba ho qala ba tatellano

Ka kakaretso, boleng ba ho qala ba tatellano ke 1, empa haeba u hloka ho hlakisa boleng ba ho qala ba 100, re ka e etsa ka polelo e latelang:

mysql > CREATE TABLE昆虫
     - > - > id INT UNSIGNED NOT NULL AUTO_INCREMENT - > PRIMARY KEY id ),- > name VARCHAR 30 NOT NULL - > date DATE NOT NULL - > origin VARCHAR 30 NOT NULL
 engine = innodb auto_increment = 100 charset = utf8 ; 
    
    
     
    
    

Kapa u ka sebelisa polelo e latelang ka mor'a hore tafole e thehoe ka katleho:

mysql > ALTER TABLE t AUTO_INCREMENT = 100 ; 

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