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  • 052-164

    Examine the command that is used to create a table:
    SQL> CREATE TABLE orders ( oid NUMBER(6) PRIMARY KEY,
    odate DATE, ccode NUMBER (6),
    oamt NUMBER(10,2) )
    TABLESPACE users;
    Which two statements are true about the effect of the above command? (Choose two.)
    A. A CHECK constraint is created on the OID column.
    B. A NOT NULL constraint is created on the OID column.
    C. The ORDERS table is the only object created in the USERS tablespace.
    D. The ORDERS table and a unique index are created in the USERS tablespace.
    E. The ORDERS table is created in the USERS tablespace and a unique index is created on the OID column in the SYSTEM tablespace.

    加在 OID 列上的是主键约束,包含唯一约束和非空约束,A 错,B 对
    因为 OID 上有主键索引,所以会自动创建唯一索引,也在 USERS 表空间,CE 错,D 对

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  • 原文地址:https://www.cnblogs.com/Babylon/p/8039064.html
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