Monday, August 6, 2012

List of Important My SQL Query used

1.         a)         Create your own database.
 create database Practical;

b)         Create table within it with the following fields giving name as Employee
            table.   (Empno,  empname, Job, Salary, Deptno.)

create table Practical.Employee(
Empno int(5),
Empname varchar(50),
Job varchar(50),
Salary float(10,2),
Deptno int(3)


c)         Insert five records in above created table.
insert into Practical.employee values(00019,'Sanjay Mishra', 'Associate Test Engineer',20800.00,901);
insert into Practical.employee values(00020,'Rakesh Sah','Network Support Engineer',15000.50,912);
insert into Practical.employee values(00021,'Yadvendra Dutt Yadav', 'Associate Test Engineer',20800.00,920);
insert into Practical.employee values(00023,'Manoj Negi','Senior Test Engineer',93000.00,901);
insert into Practical.employee values(00022,'Devendra Kumar','Associate Test Engineer',20800.00,915);


d)         Verify by displaying data by select statement.

Select * from Practical.employee;


2.         Use Employee table :
a)         Display records of a selected deptno.
            Select * from Practical.employee where Deptno=901;


b)         Display the record of selected person.
            Select * from Practical.employee where Empname=’Sanjay Mishra’;

c)         Display the record of selected Job.
            Select * from Practical.employee where Job=”Associate Test Engineer”;

d)         Display the records of given selected salary range.
            Select * from Practical.employee where Salary between 10000 and 30000;

e)         Display only the selected columns.
Select Empname, Job  from Practical.employee;

f)          Display by adding some title to the column.
            Select Empname AS “List of Employee” from Practical.employee;

3.         Use Employee table :
a)         Add one more column to table i.e. Phone_no.
                      Alter table Practical.employee add Phone_no int(10);

            b)         Modify the Employee name column by changing the data length
                        Alter table Practical.employee Modify Empname varchar(55);

c)         Make the empno. as primary key.
            ALTER TABLE Practical.employee ADD PRIMARY KEY(Empno);

d)         Insert data in phone field of each each employee by selecting him with empno.
            UPDATE Practical.employee SET Phone_no=”9910358271” WHERE Empno=019;
UPDATE Practical.employee SET Phone_no=’7875277745’ WHERE Empno=020;
UPDATE Practical.employee SET Phone_no=’9560731770’ WHERE Empno=021;
UPDATE Practical.employee SET Phone_no=’9650022039’ WHERE Empno=022;
UPDATE Practical.employee SET Phone_no=’9540963436’ WHERE Empno=023;

4.         a)  Create another table dept with three column:
                  deptno, dname and Location with deptno was primary key.
          CREATE Table Practical.dept(
Deptno int(3) Primary Key,
Dname varchar(50),
Location varchar(30)

                 Insert records in it keeping in view deptno in employee table.

            INSERT INTO Practical.dept VALUES(901,’ Computer’,’Gurgaon’);
INSERT INTO Practical.dept VALUES(912,’HR’,’Nagpur’);
INSERT INTO Practical.dept VALUES(920,’Sales’,’Gurgaon’);
INSERT INTO Practical.dept VALUES(915,’Finance’,’Gurgaon’);

b)         Create the relation between employee table and Dept table on the basis of deptno that mean deptno in the employee will be as foreign key in that table.
            ALTER Table Practical.employee ADD FOREIGN KEY(Deptno) REFERENCES Practical.dept(Deptno);

c)         Display the available records in dept table.
            Select * FROM Practical.dept;

5.         a)   Insert some more record in employee table and verify the effects of
                 constraints applied in adding deptno.
insert into Practical.employee values(00025,'Ravi Jain', 'Manager',30000.00,913,9911004410);
insert into Practical.employee values(00026,'Saina soni', 'Technical Leader',25000.00,913,9911345510);
Unable to insert into employee table until we add deptno into dept table
INSERT INTO Practical.dept VALUES(913,’Marketing’,’Delhi’);

b)         Update records of some employee by transferring them from one dept to
UPDATE Practical.employee SET Deptno=913 WHERE Empno=23;
UPDATE Practical.employee SET Deptno=912 WHERE Empno=26;

c)         Update the  salary of some employees (give 10% increase) on dept basis
             in employee table.
UPDATE Practical.employee SET Salary=(Salary+10/100*Salary)  WHERE         Deptno=912;

d)     Delete some record from employee table and  verify the output using select.

            DELETE From Practical.employee WHERE Empno=26;

6.         a)         Count the total no of employee.
                        Select COUNT(Empno) FROM Practical.employee;

            b)         Count the sum of salary using employee table.
                        Select SUM(Salary) FROM Practical.employee;

            c)         Calculate the avg salary of employee.
                        Select AVG(Salary) FROM Practical.employee;

            d)         Determine the max and min salary of employees.
                        Select MAX(Salary) FROM Practical.employee;
                        Select MIN(Salary) FROM Practical.employee;

7.         a)  Count the no of employees deptt wise using Group by & having clauses.
            Select Deptno, Count(Deptno) FROM Practical.employee group by          Deptno Having Count(Deptno)>0;

            b)         Display the some of salaries deptt wise.
            Select Deptno, SUM(Salary) FROM Practical.employee group by Deptno;

            c)         Display avg salary deptt wise.
                        Select Deptno, AVG(Salary) FROM Practical.employee group by Deptno;

            d)         Display max and min salary deptt. wise.
                        Select Deptno, MAX(Salary) FROM Practical.employee group by Deptno;
                        Select Deptno, MIN(Salary) FROM Practical.employee group by Deptno;

8.      a)   Display emp_no and emp name from employee table alongwith deptt. name from dept table.
                        Select Empno, Empname, Dname FROM Practical.employee, Practical.dept WHERE employee.Deptno= dept.Deptno;

b)         Count employee of employee table by giving department name.
                        Select COUNT(Empno) FROM Practical.employee, Practical.dept WHERE
                        dept.Dname=’Marketing’ AND dept.Deptno=employee.deptno;

            c)      Display some more lists by using join statement.
                        Select Empname, Location FROM Practical.employee INNER JOIN Practical.dept ON employee.Deptno=dept.Deptno;

9.         a)   Create table by using sub query statement. Display the records.

                  CREATE table Practical.temp as Select * FROM Practical.employee;
                  Select * FROM Practical.temp;

b)       Create table with selected column by using sub queries. Display the output
to see  data.  
 CREATE table Practical.branch as Select DISTINCT Location FROM Practical.dept;
Select * FROM Practical.branch;

10.      a)       Create view using single table with selected columns.

CREATE VIEW Practical.newview AS SELECT Empname,Job From Practical.employee;
Select * FROM Practical.newview;             

            b)      Create view using multiple tables using selected columns.
             CREATE VIEW Practical.locview AS SELECT Empname, Job,     Location FROM Practical.employee, Practical.dept WHERE employee.Deptno=dept.Deptno;
                     Select * FROM Practical.locview;

11.      a)         Delete selected records from table by using some conditions.
                     Delete FROM Practical.employee WHERE Salary between 25000 and 50000;

            b)         Drop column from table.
                        ALTER TABLE Practical.employee DROP COLUMN Phone_no;

            c)         Truncate table.
                        Truncate table Practical.employee;

            d)         Drop table.
                        DROP TABLE Practical.dept;
As in Table employee deptno is defined as Foreign  Key, so we unable to delete it . To Delete it first we have to remove table employee key constraint or delete table employe.
DROP TABLE Practical.employee;
DROP TABLE Practical.dept;

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