Answers for "sql joins"

how to join tables in sql

JOINING 2 Tables in sql

SELECT X.Column_Name , Y.Column_Name2
FROM TABLES1_NAME X 
INNER JOIN TABLES2_NAME Y ON X.Primary_key = Y.Foreign_key;


--FOR EXAMPLE
--GET THE FIRST_NAME AND JOB_TITLE
--USE EMPLOYEES AND JOBS TABLE
--THE RELATIONSHIP IS JOB_ID

SELECT E.FIRST_NAME , J.JOB_TITLE
FROM EMPLOYEES E
INNER JOIN JOBS J ON J.JOB_ID = E.JOB_ID;

joins in sql

INNER JOIN:
is used when retrieving data from multiple
tables and will return only matching data.

LEFT OUTER JOIN:
is used when retrieving data from
multiple tables and will return
left table and any matching right table records.

RIGHT OUTER JOIN:
is used when retrieving data from
multiple tables and will return right
table and any matching left table records

FULL OUTER JOIN:
is used when retrieving data from
multiple tables and will return both
table records, matching and non-matching.



INNER JOIN :
SELECT select_list From TableA A
Inner Join TableB B
On A.Key = B.Key


LEFT OUTER JOIN :
SELECT select_list From TableA A
Left Join TableB B
On A.Key = B.Key

(where b.key is null)//For delete matching data



RIGTH OUTER JOIN :
SELECT select_list From TableA A
Right Join TableB B
On A.Key = B.Key


FULL JOIN :
SELECT select_list From TableA A
FULL OUTER Join TableB B
On A.Key = B.Key

full join sql

#The FULL JOIN keyword return rows when there is a match in one of the tables
synatax->SELECT column_name(s)
FROM table_name1
FULL JOIN table_name2
ON table_name1.column_name=table_name2.column_name 
/////example////
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo
FROM Persons
FULL JOIN Orders
ON Persons.P_Id=Orders.P_Id
ORDER BY Persons.LastName

sql join

-- Rows with ID existing in both a, b and c
-- JOIN is equivalent to INNER JOIN
SELECT a.ID, a.NAME, b.VALUE1, c.VALUE1 FROM table1 a 
  JOIN table2 b ON a.ID = b.ID
  JOIN table3 c ON a.ID = c.ID
WHERE a.ID >= 1000;
-- ⇓ Test it ⇓ (Fiddle source link)

join three tables sql

Suppose we are having three table named as 
Student_details
Attendance_details
Batch_details
And we have to apply join these three tables for fetching records

Example query:
select column_names
from Student_detail as s join Attendance_details as a on
s.s_id = a.s_id join Batch_details as b on 
s.s_id = b.s_id;

Here in the above example we implemented simple join but you change it with own join requirements.

sql joins

SELECT members.`first_name` , members.`last_name` , movies.`title`
FROM members ,movies
WHERE movies.`id` = members.`movie_id`