How to Join two or more than two Tables using multiple columns | How to Join Multiple Tables #Joins

SQL JOIN
A JOIN clause is used to combine rows from two or more tables, based on a related column between them.

Different Types of SQL JOINs
(INNER) JOIN: Returns records that have matching values in both tables
LEFT (OUTER) JOIN: Returns all records from the left table,
and the matched records from the right table,
The LEFT JOIN keyword returns all records from the left table (table1),
and the matched records from the right table (table2).
The result is NULL from the right side, if there is no match.
RIGHT (OUTER) JOIN: Returns all records from the right table,
and the matched records from the left table
FULL (OUTER) JOIN: Returns all records when there is a match in either left or right table,
The FULL OUTER JOIN keyword returns all records when there is a match in left (table1)
or right (table2) table records.
Note: FULL OUTER JOIN can potentially return very large result-sets!
Tip: FULL OUTER JOIN and FULL JOIN are the same.

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[nsangchat]

OMG you are a god !!! I have been looking at minimum 10 videos and yours are the most CLEARLY illustrated ONE !! Thanks a lot

[Tabla_Tejas]

OMG you are a god !!! I have been looking at minimum 10 videos and yours are the most CLEARLY illustrated ONE !! Thanks a lot

[glorygabriel]

Explanations are so clear.
Thanks a bunch, I understand it clearly now. Please make a video for full outer join

[roi__dayz]

Great tutorial. Thank you for your help!

[alexg]

Fantastic fantastic you explained this so clearly please continue dropping videos. I am subscribing

[abhishekmahapatra]

Thank You Sir. Concept is very well explained.

[danielalejandrorobayo]

I noticed that all the 3 tables had the same key "roll_no", so it's somehow easy. However, what happens for example when table 1 and 2 has a common key, and table 2 and 3 have a different key, how to relate table 1 and 3 in this case?

[m.a.s]

If you change a record or some data in one table does it change in all the tables that reference it?

[gayatrichaudhari]

We can use distinct keywords for marks

[leecallaghan]

good day . i have an issue with my leads platform . when i enter a lead it says it already exists . i wa looking into this issue and found that it maybe an issue with a DUPLICATE KEY . does anyone have any idea .

[ToLoHasso]

One Question

If i need to print the name and percentage that they got from the same data how we can write the query for the same???

Please reply fast i am very curious

[arunajain]

why to use left join twice cannot we get the answer only with second left join

[farahamirah]

hi, i have question,
if we are using left join
from student_data as sd
left join Student_Course_Data as scd

so the table on the left is sd,

let say we add left join student_marks_data as smd
on scd.Roll_No=smd.Roll_No

are we consider table scd as left table for joining or still sd?

[deepthimurali]

Hi, can you tell why we went for left join for both joins?

[pradeepravi]

Sir can we use where condition in left join

[nsnreddy]

Could you please share with us excel sheet for practicing?

[nexsitymusichub]

hello please what is 'sd ' and ' 'scd'

[sahilrohilla]

can you share this video insert query?

[neharoy]

Can someone pls explain what query we can use in this to get the final o/p


Source A

ID Name State

1 A Delhi

2 B Delhi

3 C



Source B

ID Name State
1 A Delhi

3 C Haryana

4 D Mumbai

5 E



Final Output:

ID Name State

1 A Delhi

2 B Delhi

3 C Haryana

4 D Mumbai

5 E Null

[tejindersingh]

Aise to koi paise le k bhi ni samjhata !! 🫀