MYSQL CODE CONCEPT

Enter password: ***** Welcome to the MySQL monitor.  Commands end with ; or \g. Your MySQL connection id is 2 Server version: 5.1.33-community  MySQL Community Server (GPL) Type 'help;' or '\h' for help. Type '\c' to clear the buffer. mysql> create database cmp; Query OK, 1 row affected (0.01 sec) mysql> use cmp; Database changed mysql> create table emp     -> (     -> eid integer,     -> ename varchar(20),     -> eage integer,     -> ejob varchar(20),     -> esal integer     -> )     -> ; Query OK, 0 rows affected (0.06 sec) mysql> select * from emp; Empty set (0.00 sec) mysql> insert into emp (eid,ename,eage,ejob,esal) values(1001,'Kumar',23,'Tech',1 8000); Query OK, 1 row affected (0.05 sec) mysql> select * from emp; +------+-------+------+------+-------+ | eid  | ename | eage | ejob | esal  | +------+-------+------+------+-------+ | 1001 | Kumar |   23 | Tech | 18000 | +------+-------+------+------+-------+ 1 row in set (0.00 sec) mysql> insert into emp(eid,ename,eage,ejob,esal) values(1001,'Kumar',23,'Tech',1 8000); Query OK, 1 row affected (0.03 sec) mysql> select * from emp; +------+-------+------+------+-------+ | eid  | ename | eage | ejob | esal  | +------+-------+------+------+-------+ | 1001 | Kumar |   23 | Tech | 18000 | | 1001 | Kumar |   23 | Tech | 18000 | +------+-------+------+------+-------+ 2 rows in set (0.00 sec) mysql> delete from emp; Query OK, 2 rows affected (0.03 sec) mysql> select * from emp; Empty set (0.00 sec) mysql> delete from emp where eid=1001; Query OK, 0 rows affected (0.00 sec) mysql> drop table emp; Query OK, 0 rows affected (0.05 sec) mysql> select * from emp; ERROR 1146 (42S02): Table 'cmp.emp' doesn't exist mysql> create table emp     -> (     -> eid integer primary key,     -> ename varchar(20),     -> eage integer,     -> ejob varchar(20),     -> esal integer     -> ); Query OK, 0 rows affected (0.05 sec) mysql> insert into emp (eid,ename,eage,ejob,esal)  values(1001,'Kumar',23,'Tech',1 8000); Query OK, 1 row affected (0.01 sec) mysql> insert into emp (eid,ename,eage,ejob,esal) values(1001,'Kumar',23,'Tech',1 8000); ERROR 1062 (23000):  Duplicate entry '1001' for key 'PRIMARY' mysql> select * from emp; +------+-------+------+------+-------+ | eid  | ename | eage | ejob | esal  | +------+-------+------+------+-------+ | 1001 | Kumar |   23 | Tech | 18000 | +------+-------+------+------+-------+ 1 row in set (0.00 sec)