الأجوبة
CREATE TABLE IF NOT EXISTS countries (
COUNTRY_ID varchar(2) NOT NULL UNIQUE PRIMARY KEY,
COUNTRY_NAME varchar(40) NOT NULL,
REGION_ID decimal(10,0) NOT NULL
);
The above statement can be written like below.
Code:
CREATE TABLE countries (
COUNTRY_ID varchar(2) NOT NULL DEFAULT '',
COUNTRY_NAME varchar(40) DEFAULT NULL,
REGION_ID decimal(10,0) DEFAULT NULL,
PRIMARY KEY (COUNTRY_ID));
Output:
postgres=# postgres=# CREATE TABLE IF NOT EXISTS countries ( postgres(# COUNTRY_ID varchar(2) NOT NULL UNIQUE PRIMARY KEY, postgres(# COUNTRY_NAME varchar(40) NOT NULL, postgres(# REGION_ID decimal(10,0) NOT NULL postgres(# ); CREATE TABLE
Here is the command to see the structure of the created table :
postgres=# \d countries
Table "public.countries"
Column | Type | Modifiers
--------------+-----------------------+-----------
country_id | character varying(2) | not null
country_name | character varying(40) | not null
region_id | numeric(10,0) | not null
Indexes:
"countries_pkey" PRIMARY KEY, btree (country_id)
أسئلة مشابهة
القوائم الدراسية التي ينتمي لها السؤال
معلومات ذات صلة