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  • 3.学会命令行管理代码

    3.学会命令行管理代码
    大航海时代1:世界的创建

    --------------表的操作:海贼王世界
    CREATE DATABASE ONE_PIECE
    DROP DATABASE ONE_PIECE


    CREATE TABLE ROLE(
    ID INT IDENTITY(1,1) ,
    NAME VARCHAR(20),
    AGE INT ,
    REWARD INT
    )

    CREATE TABLE AREA(
    ID INT IDENTITY(1,1),
    NAME VARCHAR(20),
    REMARK TEXT,
    )
    SP_RENAME 'AREA1' , 'AREA'
    DROP TABLE AREA


    INSERT INTO ROLE(NAME , AGE , REWARD ) VALUES('lu.fei' , 20 , 5 );
    select * from ROLE ;
    delete from ROLE;

    ALTER TABLE ROLE DROP COLUMN AREA_ID;
    ALTER TABLE ROLE ADD AREA_ID INT;
    ALTER TABLE ROLE MODIFY AREA_ID BIGINT;

    -----------2.SQL 约束
    /*
    1.NOT NULL
    2.UNIQUE
    3.PRIMARY KEY :拥有自动定义的 UNIQUE 约束
    4.FOREIGN KEY :一个表中的 FOREIGN KEY 指向另一个表中的 PRIMARY KEY。
    5.CHECK CHECK 约束用于限制列中的值的范围。
    6.DEFAULT DEFAULT 约束用于向列中插入默认值
    */
    1.ALTER TABLE ROLE MODIFY NAME NOT NULL
    2.ALTER TABLE ROLE ADD UNIQUE( NAME)
    ALTER TABLE ROLE ADD CONSTRAINT UC_PERSON UNIQUE( NAME , AGE )
    ALTER TABLE ROLE DROP CONSTRAINT UC_PERSON
    3.ALTER TABLE ROLE ADD PRIMARY KEY( ID )
    ALTER TABLE ROLE ADD CONSTRAINT PK_PERSON PRIMARY KEY ( ID ,NAME )
    ALTER TABLE ROLE DROP CONSTRAINT PK_PERSON

    4.ALTER TABLE ROLE ADD FOREIGN KEY (AREA_ID) REFERENCES AREA(ID)
    ALTER TABLE ROLE ADD CONSTRAINT fk_PerOrders FOREIGN KEY (AREA_ID) REFERENCES AREA(ID)
    ALTER TABLE ROLE DROP CONSTRAINT fk_PerOrders

    5.ALTER TABLE ROLE ADD CHECK (AGE<30)
    ALTER TABLE ROLE ADD CONSTRAINT chk_Person CHECK (AGE<30 AND NAME IS NOT NULL)
    ALTER TABLE ROLE DROP CONSTRAINT chk_Person
    INSERT INTO ROLE(AGE , NAME ) VALUES( 5,'yai si ')

    --6
    ALTER TABLE ROLE ALTER COLUMN REWARD SET DEFAULT 'not find'
    ALTER TABLE ROLE ALTER COLUMN REWARD DROP DEFAULT
    ------------3.索引

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  • 原文地址:https://www.cnblogs.com/0to9/p/6063933.html
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