postgres=# \c shafeen;
You are now connected to database "shafeen" as user "postgres".
shafeen=# create table customer(cust_no varchar(5),cust_name varchar(15),age int phone varchar(10
shafeen(# ));
ERROR:  syntax error at or near "phone"
LINE 1: ...(cust_no varchar(5),cust_name varchar(15),age int phone varc...
                                                             ^
shafeen=# create table customer(cust_no varchar(5),cust_name varchar(15),age int, phone varchar(10
));
CREATE TABLE
shafeen=# insert into customer values(100,'amal',18,221930);
INSERT 0 1
shafeen=# insert into customer values(101,'mithilaj',21,221930);
INSERT 0 1
shafeen=# insert into customer values(101,'arun',20,221930);
INSERT 0 1
shafeen=# insert into customer values(101,'hanna',20,22930);
INSERT 0 1
shafeen=# insert into customer values(101,'shahnaa',20,2223930);
INSERT 0 1
shafeen=# select * from customer;
 cust_no | cust_name | age |  phone  
---------+-----------+-----+---------
 100     | amal      |  18 | 221930
 101     | mithilaj  |  21 | 221930
 101     | arun      |  20 | 221930
 101     | hanna     |  20 | 22930
 101     | shahnaa   |  20 | 2223930
(5 rows)

shafeen=# drop customer;
ERROR:  syntax error at or near "customer"
LINE 1: drop customer;
             ^
shafeen=# delete customer;
ERROR:  syntax error at or near "customer"
LINE 1: delete customer;
               ^
shafeen=# drop *from  customer;
ERROR:  syntax error at or near "*"
LINE 1: drop *from  customer;
             ^
shafeen=# drop * from  customer;
ERROR:  syntax error at or near "*"
LINE 1: drop * from  customer;
             ^
shafeen=# select * from customer;
 cust_no | cust_name | age |  phone  
---------+-----------+-----+---------
 100     | amal      |  18 | 221930
 101     | mithilaj  |  21 | 221930
 101     | arun      |  20 | 221930
 101     | hanna     |  20 | 22930
 101     | shahnaa   |  20 | 2223930
(5 rows)

shafeen=# alter table customer add(d_birth date);
ERROR:  syntax error at or near "("
LINE 1: alter table customer add(d_birth date);
                                ^
shafeen=# alter table customer add (d_birth date);
ERROR:  syntax error at or near "("
LINE 1: alter table customer add (d_birth date);
                                 ^
shafeen=# alter table customer add birth date;
ALTER TABLE
shafeen=# select * from customer;
 cust_no | cust_name | age |  phone  | birth 
---------+-----------+-----+---------+-------
 100     | amal      |  18 | 221930  | 
 101     | mithilaj  |  21 | 221930  | 
 101     | arun      |  20 | 221930  | 
 101     | hanna     |  20 | 22930   | 
 101     | shahnaa   |  20 | 2223930 | 
(5 rows)

shafeen=# create table cust_phone as (select cust_name ,phone from custome);
ERROR:  relation "custome" does not exist
LINE 1: ... table cust_phone as (select cust_name ,phone from custome);
                                                              ^
shafeen=# create table cust_phone as (select cust_name ,phone from customer);
SELECT 5
shafeen=# select * from cust_phone;
 cust_name |  phone  
-----------+---------
 amal      | 221930
 mithilaj  | 221930
 arun      | 221930
 hanna     | 22930
 shahnaa   | 2223930
(5 rows)

shafeen=# alter table customer drop (age);
ERROR:  syntax error at or near "("
LINE 1: alter table customer drop (age);
                                  ^
shafeen=# alter table customer drop age;
ALTER TABLE
shafeen=# select * from customer;
 cust_no | cust_name |  phone  | birth 
---------+-----------+---------+-------
 100     | amal      | 221930  | 
 101     | mithilaj  | 221930  | 
 101     | arun      | 221930  | 
 101     | hanna     | 22930   | 
 101     | shahnaa   | 2223930 | 
(5 rows)

shafeen=# alter table customer modify (cust_name varchar(25));
ERROR:  syntax error at or near "modify"
LINE 1: alter table customer modify (cust_name varchar(25));
                             ^
shafeen=# alter table customer modify cust_name varchar(25);
ERROR:  syntax error at or near "modify"
LINE 1: alter table customer modify cust_name varchar(25);
                             ^
shafeen=# alter table customer alter column cust_name type varchar(25);
ALTER TABLE
shafeen=# select * from customer;
 cust_no | cust_name |  phone  | birth 
---------+-----------+---------+-------
 100     | amal      | 221930  | 
 101     | mithilaj  | 221930  | 
 101     | arun      | 221930  | 
 101     | hanna     | 22930   | 
 101     | shahnaa   | 2223930 | 
(5 rows)

shafeen=#      delete from customer;
DELETE 5
shafeen=# select * from customer;
 cust_no | cust_name | phone | birth 
---------+-----------+-------+-------
(0 rows)

shafeen=# alter table customer rename to cust;
ALTER TABLE
shafeen=# select * from customer;
ERROR:  relation "customer" does not exist
LINE 1: select * from customer;
                      ^
shafeen=# select * from cust;
 cust_no | cust_name | phone | birth 
---------+-----------+-------+-------
(0 rows)

shafeen=# drop table cust;
DROP TABLE
shafeen=# select * from cust;
ERROR:  relation "cust" does not exist
LINE 1: select * from cust;