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2.1 SQL

2.1.1 CREATE TABLE

. , , , .

2.1.

CREATE TABLE CUSTOMER(
CustomerlD int PRIMARY KEY,
Name char(25) NOT NULL,
Street char(30) NULL,
City char(35) NULL,
State char(2) NULL,
ZipPostalCode char(5) NULL,
Country varchar(50) NULL,
AreaCode char(3) NULL,
PhoneNumber char(8) NULL,
Email varchar(100) NULL);

SQL : PRIMARY KEY, NULL/NOT NULL, UNIQUE, FOREIGN KEY CHECK. 2.1 CustomerlD Integer () Primary Key. , Name, Character () 25 . Not Null , .

SQL . CustomerlD Primary Key, , (Not Null). Primary Key , CustomerlD . , , .

, Country, VarChar(50) Null. VarChar . , Country , 50 . Null , .

Char . Name Char(25), , Name 25 , , . 25 . VarChar . , Country.

. 2.1 , Oracle

2.1. SQL Oracle

BLOB

. 4

CHAR(n)

n. 2000

DATE

7 ,

INT

38

NUMBER(n,d)

n d

VARCHAR(n)

VARCHAR2(n)

n . n=4000



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