sql join tutorial code example
Example 1: 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;
SELECT E.FIRST_NAME , J.JOB_TITLE
FROM EMPLOYEES E
INNER JOIN JOBS J ON J.JOB_ID = E.JOB_ID;
Example 2: 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.
Example 3: MySQL Join
A relational database consists of multiple related tables linking together using common columns which are known as foreign key columns. Because of this, data in each table is incomplete from the business perspective.
MySQL supports the following types of joins:
Inner join
Left join
Right join
Cross join
The following shows the basic syntax of the inner join clause that joins two tables table_1 and table_2:
SELECT column_list
FROM table_1
INNER JOIN table_2 ON join_condition;
SELECT column_list
FROM table_1
INNER JOIN table_2 USING (column_name);
SELECT column_list
FROM table_1
LEFT JOIN table_2 USING (column_name);
Here is the syntax of the right join:
SELECT column_list
FROM table_1
RIGHT JOIN table_2 ON join_condition;
The following shows the basic syntax of the cross join clause:
SELECT select_list
FROM table_1
CROSS JOIN table_2;
Example 4: sql join
SELECT Coloumn_Name(s) FROM Table_1, Table_2 WHERE Table_1.Primary_key = Table_2.Foreign_key;