code
vscode sql:
create table students(
roll number (4) not null ,
name varchar (20),
primary key (roll)
);
insert into students( roll , name)
values (121, ‘Maruf’);
insert into students (roll , name)
values (122, ‘Kanu’);
create table courses(
c_id varchar (10) not null,
c_name varchar (30),
year number (1),
term number (1),
primary key (c_id)
);
insert into courses( c_id, c_name, year, term)
values (‘123’, ‘Bangla’ , 1 , 2);
insert into courses (c_id , c_name, year , term)
values (‘124’, ‘English’ , 2, 4);
run sql code :
SQL*Plus: Release 11.2.0.2.0 Production on Thu Mar 23 02:35:33 2023
Copyright (c) 1982, 2014, Oracle. All rights reserved.
SQL> connect system
Enter password:
Connected.
SQL> create user Mobile identified by 1234;
User created.
SQL> grant all privileges to Mobile;
Grant succeeded.
SQL> @C:\Users\creat\Desktop\DBS\new.sql;
create table students(
*
ERROR at line 1:
ORA-00955: name is already used by an existing object
1 row created.
1 row created.
create table courses(
*
ERROR at line 1:
ORA-00955: name is already used by an existing object
insert into courses( c_id, c_name, year, term)
*
ERROR at line 1:
ORA-00904: “C_ID”: invalid identifier
insert into courses (c_id , c_name, year , term)
*
ERROR at line 1:
ORA-00904: “C_ID”: invalid identifier
SQL> select * from students;
ROLL NAME PHONE 3008 Maruf
3058 Kanij
3012 Maruf
121 Maruf
122 KanuSQL> select from courses;
select from courses
*
ERROR at line 1:
ORA-00936: missing expression
SQL> select * from courses;
C_NO C_NAME YEAR TERM
101 c 2 6
202 c++ 1 3
SQL> describe students;
Name Null? Type
ROLL NOT NULL NUMBER(7)
NAME VARCHAR2(20)
PHONE VARCHAR2(15)
SQL> describe courses;
Name Null? Type
C_NO NOT NULL VARCHAR2(10)
C_NAME VARCHAR2(30)
YEAR NUMBER(1)
TERM NUMBER(1)
SQL> alter table students
2 add phone varchar(15);
add phone varchar(15)
*
ERROR at line 2:
ORA-01430: column being added already exists in table
SQL> describe students;
Name Null? Type
ROLL NOT NULL NUMBER(7)
NAME VARCHAR2(20)
PHONE VARCHAR2(15)
SQL> alter table students
2 modify roll number (7);
Table altered.
SQL> alter table courses
2 rename column c_id to c_no;
alter table courses
*
ERROR at line 1:
ORA-00957: duplicate column name
SQL> describe students;
Name Null? Type
ROLL NOT NULL NUMBER(7)
NAME VARCHAR2(20)
PHONE VARCHAR2(15)
SQL> describe courses;
Name Null? Type
C_NO NOT NULL VARCHAR2(10)
C_NAME VARCHAR2(30)
YEAR NUMBER(1)
TERM NUMBER(1)
SQL> insert into students(roll, name, number)
2 values(3092, ‘Hridoy’ , 154656410);
insert into students(roll, name, number)
*
ERROR at line 1:
ORA-01747: invalid user.table.column, table.column, or column specification
SQL> insert into students (roll, name, number)
2 values (3013, ‘Tuhin’ , 166465666);
insert into students (roll, name, number)
*
ERROR at line 1:
ORA-01747: invalid user.table.column, table.column, or column specification
SQL> insert into courses (c_no, c_name, year, term)
2 values (454, ‘Itihas’, 4, 8);
1 row created.
SQL> insert into courses (c_no, c_name, year, term)
2 values(74, ‘Patihas’ , 3, 4);
1 row created.
SQL> select * from students;
ROLL NAME PHONE 3008 Maruf
3058 Kanij
3012 Maruf
121 Maruf
122 KanuSQL> select * from courses;
C_NO C_NAME YEAR TERM
101 c 2 6
202 c++ 1 3
454 Itihas 4 8
74 Patihas 3 4
SQL>
Reset system password :
SQL> conn/ as sysdba
Connected.
SQL> alter user system identified by password;