Syntax For Joining In SQL

-: Defect Page In ALM/QC :-

DEFECT/BUG/ISSUE

Basic element for defect report:

The basic elements QA tester need to mention in a defect reports are SI_NO, Defect ID, Defect Description, Steps to reproduce, Status, Priority, Severity, Test Data, Author, Comments, Browser version and Environment. 

What is automation?

                                                 What is automation?

Automation is a process that executes manual test cases into automation script and Execute that same Functionality without user interact.

Example: Let say we have test case for login to an application. For perform this test manually we need open browser, we need to navigate to the application URL, then insert valid credentials to the WEBEDIT and finally we need to click on login button.

Instead of doing manually we can easily automate this test case and run it for multiple number of users without any human interact. 

-:  Joining In SQL :-

-: Waterfall VS Agile Methodology :-

What is a join? Explain with example?

What is a join?

Join used to connect multiple table based on primary key & foreign key. Or join is used to combine rows from multiple tables.

What are Different Types of Join?

There are 4 different types of join.

1)      Inner join

2)      Cross join

3)      Outer join

Outer join are 3 types:

Ø  Left outer join

Ø  Right outer join

Ø  Full join

4)      Self-join

What is Inner join (Also called equi-join)?

The INNER JOIN keyword returns rows when there is at least one match in both tables. Inner join also known as Equi-join.

Example:

Select e.first_name, e.last_name, e.salary, e.department_id, d.department_name

From employees e, departments d

where e.department_id=d.department_id;

           

What is outer join?

The outer join retrieve the missing rows. The missing rows can be returned if outer join operator (+) is used in the join condition. The outer join operator (+) can be used in that side where information is missing.

The outer join are 3 types:

1)      Left outer join

2)      Right outer join

3)      Full outer join

Left Outer Join: Return all rows from the left table, even there are no matches in the right table. If information missing in the left table the outer join operator (+) is used only the left side of the equal sign ((+) =).

Example:

select e.first_name, e.last_name, e.salary, e.employee_id,  d.department_name

from employees e, departments d

where

e.department_id (+)=d.department_id;

Right Outer Join: Return all rows from the right table, even there are no matches in the left table. If information missing in the right table the outer join operator (+) is used only the right side of the equal sign (= (+)).

Example:

select e.first_name, e.last_name, e.salary, e.employee_id,  d.department_name

from employees e, departments d

where

e.department_id =d.department_id (+);

Full Outer Join: The FULL OUTER JOIN keyword returns all rows from the left table and from the right table. The FULL OUTER JOIN keyword combines the result of both LEFT and RIGHT joins.

Example:

select e.first_name, e.last_name, e.salary, e.employee_id, d.department_name

from employees e full join departments d

on e.department_id=d.department_id;

What is Cartesian or Cross join?

If there is no condition (where clause) between two tables than Cross join execute a result which is the number of rows in the first table multiplied by the number of rows in the second table and show all the result that’s called as cross join. It is also known as Cartesian product.

Example:

SELECT e.first_name, e.last_name, e.salary, e.department_id, d.department_name

FROM employees e, departments d;

OUTPUT will be 2889 rows which comes from 107*27

What is self-join (Also called nested join)?

A self-join is basically when a join is done on the same table. Whenever we make a sub query (also call nested) that means we are doing self-join.

Example:

select e.employee_id, e.first_name, e.last_name, e.salary, e.manager_id, m.first_name, m.last_name

from employees e, employees m

where e.manager_id=m.employee_id;

What is Union and UNION ALL?

UNION is used to select unique data from two tables whereas UNION ALL is used to select all data including duplicates from the tables.

What is the difference among UNION, MINUS and INTERSECT?

UNION combines the results from 2 tables and eliminates duplicate records from the result set.

MINUS operator when used between 2 tables, gives us all the rows from the first table except the rows which are present in the second table.

INTERSECT operator returns us only the matching or common rows between 2 result sets.

Why we use SQL?

We use SQL for Manipulate and Execute data.

What is a clause?

It is a command for SQL.

.
What is Drop?

Delete the whole table with table structure.

What is Deleting?

Delete the data records from a table, depending on where ‘clause’.

What is Truncate?

Delete all rows of table but the table structure remains in the database.

What is the different between Union and Join?

Union is to select related information from two tables and Join combines two or more tables to retrieve data from multiple tables.