ALTER TABLE

  • ADD

    格式

    ALTER TABLE [schema.]table_name ADD
        (column datatype [DEFAULT value] [constraint]
        [,column datatype [DEFAULT value] [constraint]...]);

    schema :結構名稱
    table_name : 表格名稱
    column : 欄位名稱
    datatype : 資料型別
    value : 欄位預設值
    constraint : 條件約束
     
    ALTER TABLE customers
      ADD customer_name varchar2(45) ;
    ALTER TABLE customers
      ADD city varchar2(40) DEFAULT 'Seattle' ;
    ALTER TABLE customers
      ADD (customer_name varchar2(45),
           city varchar2(40) DEFAULT 'Seattle') ;
     
  • MODIFY
    ALTER TABLE customers
      MODIFY customer_name varchar2(100) NOT NULL ;
    ALTER TABLE customers
      MODIFY city varchar2(75) DEFAULT 'Seattle' NOT NULL ;
    ALTER TABLE customers
      MODIFY (customer_name varchar2(100) NOT NULL,
              city varchar2(75) DEFAULT 'Seattle' NOT NULL) ;
     
  • DROP
    ALTER TABLE customers
      DROP COLUMN customer_name ;
     
  • ADD PRIMARY KEY
    ALTER TABLE test2
    ADD CONSTRAINT test_id_pk
    PRIMARY KEY (test_id) ;
     

參考:
Oracle / PLSQL: ALTER TABLE Statement
Oracle SQL學習筆記本: ALTER TABLE...ADD介紹
ORA-01735: invalid ALTER TABLE option | PL/SQL Tutorial Oracle for beginners
 

 

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