索引的数量是多少？ [英] Which is the number of indexes ?

问题描述

Table adresses estre created with the following statement . How many indexes will be created when you create it ?

我尝试了什么：



CREATE TABLE ADDRESSES（

NAME VARCHAR2（40）PRIMARY KEY，

STREET VARCHAR2（40），

CITY VARCHAR2（40）

状态字符（2）参考状态（ST_CODE），

ZIP编号（5）非空，

PHONE VARCHAR2（12）独一无二）;





A）0

B）1 br />
C）2

D）3

What I have tried:

CREATE TABLE ADDRESSES(
NAME VARCHAR2 (40) PRIMARY KEY,
STREET VARCHAR2(40),
CITY VARCHAR2(40)
STATE CHAR(2) REFERENCES STATE(ST_CODE),
ZIP NUMBER(5) NOT NULL,
PHONE VARCHAR2(12) UNIQUE);


A)0
B)1
C)2
D)3

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